Reference Manual The specifications and data given in this documentation are subject to modification without prior notice. Unless otherwise stated, any names and data used in the examples are completely fictitious. No part of this documentation may be reproduced or transmitted for whatever purpose, in any form or by any means (electronically or mechanically), without the express permission in writing from DataKustik GmbH. DataKustik GmbH. All rights reserved. Gilching, October 2017 (release 2018, 161.4800) CadnaA is a registered trademark of Datakustik GmbH, Gilching, Germany. Contents III Contents License Agreement. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .XV Index. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . XIX Chapter 1 - Introduction Structure of CadnaA documentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3 New Features of CadnaA 2018 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7 Notations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-11 Literature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-13 Chapter 2 - Sound Sources Industrial Sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3 Common Input Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7 ISO 9613 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-27 Nordic Prediction Method 1996 . . . . . . . . . . . . . . . . . . . . . . . . . . 2-29 Nord 2000. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-31 Ljud från vindkraftverk . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-33 BS 5228 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-35 Harmonoise . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-37 Concawe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-39 NMPB-Industry 2008 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-41 CNOSSOS-EU (Industry) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-43 Schall03 (2014) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-45 HJ 2.4 (2009) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-47 Further Procedures for Industrial Noise . . . . . . . . . . . . . . . . . . . . 2-49 Directivity at Industrial Sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-51 Sound Radiation from Chimneys or Stacks . . . . . . . . . . . . . . . . . 2-57 Sound Radiation from Elements & Openings . . . . . . . . . . . . . . . . 2-59 Frequency-dependent Directivity . . . . . . . . . . . . . . . . . . . . . . . . . 2-63 Tennis - Point-of-Serve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-67 Roads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-73 CadnaA - Reference Manual Contents IV Common Input Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-75 RLS-90 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-89 Nordic Prediction Method 1996 . . . . . . . . . . . . . . . . . . . . . . . . . 2-103 NMPB-Routes 1996 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-111 NMPB-Routes 2008 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-119 CNOSSOS-EU (Road) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-127 CRTN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-137 TNM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-145 Czech Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-151 SonRoad . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-157 HJ 2.4 (2009) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-161 Further Procedures for Road Noise . . . . . . . . . . . . . . . . . . . . . . 2-167 Air Pollution according to MLus-92. . . . . . . . . . . . . . . . . . . . . . . 2-169 Crossings with Traffic Lights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-171 Railways . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-179 Common Input Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-181 Schall 03 (1990) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-189 Schall 03 (2014) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-195 Nordic Prediction Method 1996 . . . . . . . . . . . . . . . . . . . . . . . . . 2-205 CRN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-211 SRM II . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-217 NMPB-Fer 1996 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-225 NMPB-Fer 2008 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-229 CNOSSOS-EU (Railway) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-233 FTA / FRA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-243 Further Procedures for Railway Noise . . . . . . . . . . . . . . . . . . . . 2-253 Train Class Libraries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-255 Traffic-Count Calculator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-269 Parking Lots. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-271 RLS-90 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-275 LfU-Study (2007) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-277 SN 640 578 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-285 Pass-By of individual Vehicles. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-289 Optimisable Source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-299 CadnaA - Reference Manual Contents V Chapter 3 - Obstacles Building . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3 Residential and non-residential Buildings . . . . . . . . . . . . . . . . . . . 3-9 Acoustic Transparency (%) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-11 Snap Point to Facade . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-17 Edit Facades . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-21 Defining a Roof Ridge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-33 Generate Building. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-39 Barrier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-41 Floating Barrier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-43 Barrier with special crowning . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-47 Barrier with transmission . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-53 Barrier staggered in height . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-59 Bridge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-61 Ground Absorption Areas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-63 Built-Up Areas and Foliage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-65 Cylinder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-69 3D-Reflector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-71 Embankment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-87 Automatically Optimize Noise Barriers . . . . . . . . . . . . . . . . . . . . . 3-91 Chapter 4 - Topography Terrain generating Objects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-9 Contour Line . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-11 Height Point . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-15 Line of Fault . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-19 Object’s Geometry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-21 Point-like Objects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-21 Line-like Objects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-25 Area-like Objects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-29 Additional Input Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-31 Topography-specific Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-37 Fit Objects to DTM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-39 Fit DTM to Object . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-45 CadnaA - Reference Manual Contents VI Generate Terrain Contours from Height Points . . . . . . . . . . . . . . 4-51 Generate a Grid of Height Points from Terrain Contours . . . . 4-57 Generate Cluster of Heights Points from Bitmap . . . . . . . . . . . . 4-63 Chapter 5 - Immissions Receiver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3 Consistency Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-9 Partial Levels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-11 Area of Designated Land Use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-13 Type of Land Use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-15 Receiver Grid. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-17 Grid Specification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-25 Grid Appearance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-31 Grid Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-39 Grid Arithmetic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-41 Generating a Grid from Noise Contours . . . . . . . . . . . . . . . . . . . . 5-51 Vertical Grid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-57 Building Evaluation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-61 Building Noise Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-69 Result Table for the Building Noise . . . . . . . . . . . . . . . . . . . . . . . 5-79 Level Difference Map for Building Noise . . . . . . . . . . . . . . . . . . . 5-83 Chapter 6 - Calculation Sound Rays and Reflection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-3 Sound Rays at Point Sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-5 Sound Rays at Line and Area Sources . . . . . . . . . . . . . . . . . . . . . 6-7 Projection at extended Sound Sources . . . . . . . . . . . . . . . . . . . . . 6-9 Reflection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-13 Reflection of the 1st Order . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-15 Reflections of Higher Order . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-19 Displaying Sound Rays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-23 Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-31 Country Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-33 General Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-35 Partition Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-51 CadnaA - Reference Manual Contents VII Reference Time Tab. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-59 Evaluation Parameters Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-65 DTM Digital Terrain Model Tab . . . . . . . . . . . . . . . . . . . . . . . . . . 6-71 Ground Absorption Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-75 Reflection Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-77 Industry Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-87 ISO 9613 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-93 Nordic Prediction Method (1996) . . . . . . . . . . . . . . . . . . 6-111 Nord 2000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-117 Ljud från vindkraftverk . . . . . . . . . . . . . . . . . . . . . . . . . . 6-123 BS 5228 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-127 Harmonoise . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-133 Concawe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-141 NMPB-Industry 2008 . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-151 CNOSSOS-EU . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-155 HJ 2.4 (2009) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-157 Road Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-159 RLS-90 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-165 Nordic Prediction Method (1996) . . . . . . . . . . . . . . . . . . 6-171 NMPB-Routes 1996 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-179 NMPB-Routes 2008 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-185 CNOSSOS-EU . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-189 CRTN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-195 TNM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-205 Czech Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-209 SonRoad . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-211 HJ 2.4 (2009) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-213 Railroad Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-215 Schall 03 (1990) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-221 Schall 03 (2014) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-225 Nordic Prediction Method (1996) . . . . . . . . . . . . . . . . . . 6-229 CRN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-233 SRM II . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-235 NMPB-Fer 1996 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-237 NMPB-Fer 2008 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-239 CadnaA - Reference Manual Contents VIII CNOSSOS-EU . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-243 FTA/FRA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-245 Aircraft Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-249 Optimizable Source Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-251 Adjustment of the Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-253 Selecting Data for the Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-257 Calculation Protocol. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-259 Compact Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-271 Multithreading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-273 Multiple Source Effect . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-275 Monetary Evaluation of Noise according to BUWAL . . . . . . . . . 6-281 QSI - Statistical Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-282 QSI - Statistical Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-289 Batch Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-297 PCSP - Program Controlled Segmented Processing . . . . . . . . . . . . . . 6-303 Chapter 7 - Import Import Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-3 Allocate Object Type to Layer . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-5 Import only Section. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-7 Importing selected Object Types . . . . . . . . . . . . . . . . . . . . . . . . . 7-11 Coordinate Transformation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-13 Unknown Attributes to Memo-Variable . . . . . . . . . . . . . . . . . . . . . 7-29 Process Ring Polygons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-33 Import Formats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-35 CadnaA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-37 ArcView . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-39 Atlas GIS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-43 MicroStation-DGN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-45 AutoCad-DWG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-47 AutoCad-DXF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-49 SketchUp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-61 EDBS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-69 GML (UK) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-71 CityGML . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-73 CadnaA - Reference Manual Contents IX Open Street Map XML . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-77 MapInfo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-85 Sicad . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-87 Special Formats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-89 Stratis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-91 WINPUT-DGM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-95 Building Height Points . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-97 ASCII-Objects. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-99 ASCII-Grid DTM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-107 ASCII-Spectra . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-109 Third-Party Software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-111 Import / Export of Numbers of Trains . . . . . . . . . . . . . . . . . . . . . 7-113 Import via ODBC Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-115 Chapter 8 - Digitizer Digitizer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-3 Digitizing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-5 Tablet Menu. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-9 Chapter 9 - Graphics Limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-3 Coordinate Grid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-7 Object Snap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-9 Coordinate System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-11 Object Appearance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-13 General Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-21 Symbol Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-25 Line Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-27 Line of Symbols Tab. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-29 Fill Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-31 Fill with Symbols Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-33 Fill with Hatch Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-37 3D Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-39 Dialog Color . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-41 Default Object Appearance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-49 CadnaA - Reference Manual Contents X Edit Toolbar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-51 Layer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-53 Fix Objects. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-55 Auxiliary Polygon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-57 Section. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-59 Settings for Objects with Frames. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-61 Text Box . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-63 Level (dB) Box . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-69 Symbol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-71 Station Mark . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-77 Cross Section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-79 3D-Wire Model. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-81 3D-Special View . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-85 Menu Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-91 Miscellaneous . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-99 Chapter 10 - Bitmaps Insert Bitmaps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-5 Bitmap Size and Position . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-7 Import Bitmap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-11 Delete Bitmap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-17 Web-Bitmaps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-19 Chapter 11 - Tables Object Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-3 Buttons in Object Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-11 Editing Object Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-13 Changing Column Content . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-19 Result Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-23 Editing the Result Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-25 Chapter 12 - Libraries Spectra . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-5 Sound Level Spectra . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-7 Sound Reduction Spectra . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-23 CadnaA - Reference Manual Contents XI Absorption Spectra . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-27 Road Surfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-31 Modify Spectrum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-33 SET-S . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-39 Diurnal Patterns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-47 Symbol Library. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-51 Text Blocks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-63 Color Palettes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-67 Default Color Palettes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-77 Library Manager . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-79 Purge Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-81 Chapter 13 - Print & Export Designing and printing the Graphics . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-3 Plot-Designer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-3 PlotDesigner - Cell Types. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-17 Cell Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-21 Print Graphics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-35 Print Graphics using a Template File (outdated) . . . . . . . . . . . . 13-37 Designing & Printing Reports and Tables . . . . . . . . . . . . . . . . . . . . . . . 13-39 Printing Reports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-41 Template Files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-45 Print Preview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-51 Export . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-53 AutoCad DXF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-55 ArcView (*.shp). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-57 ArcView-grid (*.asc, *.hdr) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-63 Bitmap Files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-65 Text Files (*.txt, *.rtf). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-67 Word Document (*.docx) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-69 GoogleEarth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-71 QSI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-75 CadnaA - BASTIAN - link . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-77 Chapter 14 - Project Organization CadnaA - Reference Manual XII Contents ObjectTree . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-3 Variants. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-15 Groups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-21 Defining Groups. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-23 Partial Sound Levels of Groups. . . . . . . . . . . . . . . . . . . . . . . . . 14-27 Date Interval of Objects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-29 Folders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-31 Dynmap: The dynamic Noise Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-33 Prototype File . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-39 Automatic Saving of Files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-41 Automatically generated Text Blocks . . . . . . . . . . . . . . . . . . . . . . . . . . 14-43 Project Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-45 Calculation Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-47 Chapter 15 - Options X & XL Object-Scan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-3 Scanning into Single Values . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-13 Scanning into Areas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-16 Scanning into the Grid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-19 Scanning into a Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-23 Conflict Maps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-25 Grid Evaluation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-27 Population Density . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-33 Monetary Evaluation according to BUWAL. . . . . . . . . . . . . . . . . . . . . . 15-37 Application to Areas of Designated Use . . . . . . . . . . . . . . . . . . 15-38 Loss in value as a single value . . . . . . . . . . . . . . . . . . . . . . . . . 15-43 Loss in value for all areas of designated land-use . . . . . . . . . . 15-45 Loss in value on a grid map. . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-48 Close Polygons. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-49 Delete Height Points . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-55 Lua Scripting Language . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-57 Introduction to Lua. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-59 Syntax and Data Types . . . . . . . . . . . . . . . . . . . . . . . . . 15-59 Operators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-61 Declaration and scope of variables . . . . . . . . . . . . . . . . 15-62 CadnaA - Reference Manual Contents XIII Program flow: control structures & loops . . . . . . . . . . . . 15-64 Lua and CadnaA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-67 Validity of CadnaA-Lua-Objects . . . . . . . . . . . . . . . . . . . 15-79 Handling of Variants in CadnaA-Lua . . . . . . . . . . . . . . . 15-79 Addressing Evaluation Parameters in CadnaA-Lua . . . . 15-81 Symbols for Lua-Preset-Files . . . . . . . . . . . . . . . . . . . . . 15-81 Action „Lua Command“ . . . . . . . . . . . . . . . . . . . . . . . . . 15-82 LUA-Events . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-84 Reference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-89 Commands on Project Level . . . . . . . . . . . . . . . . . . . . . 15-89 Limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-91 Grid and Grid Arithmetics . . . . . . . . . . . . . . . . . . . . . . . . 15-92 Grid Point . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-93 Table-Object . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-95 CadnaA-Object . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-97 Polygon-Object . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-98 Polygon-Vertex-Object (Polygon point) . . . . . . . . . . . . . 15-99 Partial Level . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-99 Variants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-100 Building Noise Map . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-101 Configuration of Calculation . . . . . . . . . . . . . . . . . . . . . 15-101 3D-Special . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-102 Global Variable CLOSE_DIALOG... . . . . . . . . . . . . . . . 15-104 CadnaA - Reference Manual XIV Contents CadnaA - Reference Manual License Agreement XV License Agreement Important notice: Please carefully read this software license agreement before using the software. By installing the software, you agree to be bound by the terms and conditions of this license agreement. If you do not agree to all of the terms and conditions of this license agreement, you are not allowed to use the software. 1. SUBJECT MATTER OF THE AGREEMENT: DataKustik GmbH grants the customer a non-exclusive right to use for the software including its documentation. A customer is a natural or legal person. Subsidiaries or affiliated companies are separate legal entities and therefore separate customers. The right of use is granted for one customer only. The property right and the copyright in the software do not pass to the customer. The license is issued for use on one single computer workstation. For any further computer workstation, a separate license agreement will be required. 2. COPY PROTECTION: The software is copy protected with a dongle. The license dongle represents the value of the software and cannot be replaced in case of loss. The DataKustik GmbH takes no responsibility or obligation for the purchased license dongle. The customer shall bear full responsibility in case of loss and may purchase a new license according to the current price conditions. 3. COPY PROHIBITON: Neither the licensed software nor the documentation, in whole or in parts, may be copied. The only exception to this rule is the generation of a machine-readable copy of the software for backup or archiving purposes. Any copy made by the customer for these purposes must include all copyright or other proprietary notices contained on the original. 4. ASSIGNMENT AND TRANSFER: The assignment to third parties of rights and obligations arising out of this license agreement, and the transfer of the software for use is subject to prior express written per- CadnaA - Reference Manual XVI License Agreement mission of DataKustik GmbH. In particular the customer may not rent, lease, lend or sublicense the software without prior express written permission of DataKustik GmbH. The splitting of one license bundle (client-server-license) is subject to prior written permission of DataKustik GmbH. 5. USE OF TRADEMARKS: The customer is permitted to use the trademarks and commercial names used by DataKustik GmbH to identify printouts, provided that (a) these printouts were produced by the licensed software using an electronic printing medium, (b) these trademarks and commercial names are identified in the same way as done so by DataKustik GmbH, and (c) the customer stops using these trademarks and commercial names upon termination of this license agreement. 6. PROHIBITION OF MODIFICATION: The customer may not modify the licensed software in any way or have it modified by third parties. The customer may not decompile, reverse engineer, or disassemble the software or any part thereof. 7. UNAUTHORISED USE: The customer undertakes to ensure that his employees and any other person subject to the customer's instructions, having access to the licensed software, comply with all obligations of safeguarding and the duty of care and diligence arising out of this agreement. The customer furthermore undertakes to ensure that no person gains access to the licensed software with the aim of deriving the source code. If the customer becomes aware of any such persons as indicated in the first sentence of this clause, using the software in violation of the obligations of safeguarding and the duty of care and diligence mentioned, he shall immediately take any possible action to prevent such use contrary to agreement. He shall inform DataKustik GmbH in writing of any such use contrary to agreement, should it continue nonetheless. 8. INDEMNITY: DataKustik GmbH is entitled to the protection rights and the copyright in the licensed software. The customer can be held liable by DataKustik GmbH for any violation of such protection rights which he is answerable for. CadnaA - Reference Manual License Agreement XVII 9. WARRANTY: The customer recognises that errors in the software and the pertinent documentation cannot be excluded given the state of the art. If, within 30 days from delivery to the customer, the customer asserts any deviation of the software from the software specifications/ description, he has the right to return the defective software including the dongle to his supplier, and to demand delivery of a new software version. If remedial measures cannot be taken or fail, the customer has the right to demand a cancellation of the agreement. In this case, the customer shall destroy any and all copies that he may have generated. In states where national legislation requires a term of notice of defect of more than 30 days, that legally provided term shall be taken to apply, if the software is purchased and used there. Any further warranty claims are expressly excluded. DataKustik GmbH neither warrants that the software features satisfy the customer's requirements nor that they are compatible in the selection made by the customer. Any liability for lost profit, for damage to or loss of saved data and for any other indirect or consequential damages is also excluded, unless resulting from grossly negligent or wilful action by DataKustik GmbH. Any warranty, liability or indemnity, etc. promised by a third party (e.g. by a distributor) to be granted by DataKustik GmbH is not binding for DataKustik GmbH. 10. PROTECTION RIGHTS OF THIRD PARTIES: If the customer is held liable by a third party because of an alleged violation of a patent right, copyright, or any other protection right that said third party may have in the licensed software, DataKustik GmbH shall immediately be informed in writing of the alleged violation of protection rights, and DataKustik GmbH shall be supported sufficiently in any lawsuit. If the customer is held liable by a third party in this way, DataKustik GmbH has the right to choose, at its own discretion, to either provide the customer with the appropriate license by the third party in question, to modify the licensed software, to supply the customer with an equivalent different software, or to take back the licensed software, in which case the license fees shall be fully reimbursed to the customer. DataKustik GmbH is not liable for violations of protection rights which are due to the fact that the customer altered or modified the licensed software to CadnaA - Reference Manual XVIII License Agreement suit his needs, or that the licensed software is used or sold in combination with other software, hardware or consumables not supplied by DataKustik GmbH. This material liability is the total of any liability assumed by DataKustik GmbH for violations of any patent right, trademark right, copyright or other intangible property rights. 11. SOFTWARE UPDATES: As an error-free data exchange of our software can only be granted if the software of one customer is at the same version level on all computer workstations, DataKustik always supplies the most recent version of the licensed software to the customer. In the case of acquiring additional license rights, the customer is obliged to update the existing licenses beforehand. A parallel use of different versions within the same customer is not allowed for the same reason. DataKustik GmbH reserves the right to charge the customer with additional license fees for such updated versions. 12. LEGAL INVALIDITY OF CONTRACTUAL PROVISIONS: Should one single or several provisions of this agreement be or become invalid, this shall not affect the effectiveness of the remaining provisions of the agreement. The invalid provision(s) will then have to be re-interpreted or supplemented in such a way that the originally intended commercial purpose is lawfully achieved. 13. DISCLAIM: This contract, including all provided documents, represents the full agreement between the parties. Collateral agreements do not exist. All references or information by the contracting party with regard to the validity of his terms and conditions is herewith explicitly rejected. CadnaA is a registered trademark of DataKustik GmbH, Germany. CadnaA - Reference Manual Index XIX Index Lua commands and functions are not indexed! Numerics 3D-Reflector 3|71 3D-Special View 9|85 calling 9|86 Editing Objects 9|88 Generate Camera Line 9|87 Ground Texture 9|88 Menu Commands 9|91 moving in 9|87 Text Boxes in 3D 9|89 3D-Symbol 9|71 library 12|56 Options 9|73 A Absorption Alfa 3|2 Spectra 12|27 Acoustic Transparency 3|11 Additional Width left/right 2|87 Adjusting column width 11|8 Affine Transformation 7|17 Air Attenuation, user-defined 6|105 Aircraft Tab 6|249 Angle Scanning 6|48 Appearance CadnaA - Reference Manual of Grid 5|31 of Objects 9|13 ArcView 7|39, 13|57 ArcView ASCII Grid 7|41 Area (m²) 2|20 Area of Designated Land Use 5|13 Area sources follow terrain 6|74 Areas of Equal Sound Level 5|32 Arithmetic see Building Noise Map Arithmetics see Grid Arithmetics ASCII-file 4|17 ASCII-Grid DTM 7|107, 7|109 Assign Facade Bitmaps example 3|28 Assign Roof Bitmap example 3|29 Atlas GIS 7|43 Attenuation 2|14 Auralisation 2|294 Auto save 14|41 Auto-Assignment of Objects 14|9 AutoCad 13|55 AutoCad-DWG 7|47 AutoCad-DXF 7|49 Automatic Saving of Files 14|41 Auxiliary Polygon 9|57 Average Height (m) 2|94, 2|165 B Background beyond the Limits 9|100 XX Index Barrier 3|41 cantilever 3|47 crowning 3|47 Floating Barrier 3|43 optimize noise barriers 3|91 with special Crowning 3|47 Barrier Coefficient 6|104 BASTIAN, connection with CadnaA 13|77 Batch Operation 6|297 Bitmap 7|89, 10|1 calibrate 10|7 convert to monochrome 10|9 fix Bitmap 10|9 Formats 10|11 generate height point cluster 4|63 Import from GoogleEarth 10|12 show bitmap 10|9 transforming Bitmaps 10|10 Transparency 10|9 Web-Bitmaps 10|19 Bridge 3|61 Building 3|3 acoustic transparency 3|11 Deactivate Point Objects inside 3|7 Edit Facades 3|21 facade bitmaps 3|24 Generate Building 3|39 Height Points 7|97 Level-Difference-Map 5|83 Noise Maps of 5|69 Result Table, Building Noise 5|79 roof bitmap 3|27 Snap Point to Building Facade 3|17 Building Evaluation 5|61 Building Height Points 7|97 Built-Up Areas 3|65 Built-Up Areas & Foliage 3|65 C Cadna.dat 12|3 Calc Width of Roads 2|95 Calculation 6|275 Batch Operation 6|297 Compact Protocol 6|271 Grid 5|39 HAP 6|275 Limits 9|3 QSI 6|282, 6|289 Selecting Data for 6|257 Calculation Area 6|257 Calculation Protocol 6|259 Canceling Grid Calculation 5|40 cantilever 3|47 Check Consistency 5|9 CityGML 7|71 Class Width 5|35 Closing Buildings 15|49 Color Palette Defining a new palette 12|67 dialog options 12|71 Example 12|73, 12|74 Import old Palette-File 5|36 option Progressive Colors 12|71 Color Palette "default" 5|33 Color Palette "file" 5|33 Color Palettes 5|33, 12|67 Compact Protocol 6|271 Configuration 6|31 Conflict Maps 15|25 Contour Lines 4|11 displaying triangulated lines 6|72 generate from height points 4|51, 4|57 Convert to monochrome (for PDF) 10|9 Coordinate Grid 9|7 CadnaA - Reference Manual Index XXI Coordinate System global 9|11, 10|14 Median Strip 9|12 NTv2 reference systems 9|11 Offset 9|12 User-defined coordinate system 9|12 Coordinate Transformation 7|13 Affine Transformation 7|17 General Transformation 7|20 Interactive Transformation 7|22 NTv2 reference systems 7|18 Coordinates General Transformation 7|20 Copy Data Records 11|9 Correction 2|14 Country Tab 6|33 Counts, MDTD 2|82 Criteria for Calculation of Reflections min. Dist. Source - Reflector 6|85 Crossings with Traffic Lights 2|171 Crowning 3|47 Cylinder 3|69 D Data 11|4 Data Set Delete 11|4 Edit 11|4 Database ODBC interface 7|115 Deactivate Point Objects in Buildings 3|7 Defining 12|67 Delete 4|17 Grid 5|19 Grid Points 5|29 Poly points via height z 7|20 CadnaA - Reference Manual Delete Height Points 15|55 Deviation 6|42 Dialog Grid Appearance Section "Color Palettes" 5|31 Dialog Railway 2|181 Digital Terrain Model configuration tab Fit objects to DTM 4|39, 4|45 Standard Height 6|71 Digitizer 8|3 Test 8|3 Digitizing Calibrate Digitizer 8|6 Directivity 2|51 Import via ODBC 2|64 Paste via clipboard 2|64 Sound Radiation by Chimneys 2|57 Displaying Sound Rays 6|23 Displaying triangulated terrain contours 6|72 Distance Multiple Reflection 2|94, 2|165 Distance of the outer lanes 2|75 Distance Source to Reflector 6|85 Diurnal Pattern 2|83 DTM see Digital Terrain Model DXF 13|55 Dynmap 14|33 E EDBS 7|69 Edit Facades 3|21 effect related substitute level 6|275 Embankment 3|87 Emission Lm,E Road 2|82 Emission Type 2|11 Entry in CADNAA.INI 6|299 XXII Index Evaluation 15|27 Evaluation Parameter Tab 6|65 Exact Count Data 2|83 Example Assign Facade Bitmaps 3|28 Assign Roof Bitmaps 3|29 Defining a group 14|24 Groups & Partial Sum Level 14|24 Level differences for Buildings 5|83 Example Files SmallCity01.cna 15|13 SmallCity02.cna 15|16, 15|19 SmallCity03a.cna 15|19 SmallCity03b.cna 15|22 SmallCity04.cna 15|23 Explicit Edges Only 6|72 Export 13|53 ArcView 13|57 ArcView Shape 13|57 DXF 13|55 GoogleEarth 13|71 RTF 13|67 Text file TXT, RTF 13|67 TXT 13|67 Exporting Template Files 13|45 F facade bitmaps 3|24 repeat in X/Y 3|25 repeat on all facades 3|25 Fault Lines 4|19 Fit Objects to DTM 4|39, 4|45 Fix Bitmap 10|9 Folding Markers 13|24 Frame Station Mark 9|77 Symbol 9|71 Frames 9|61 G General Tab 6|35 Angle Scanning 6|48 Mithra Compatibility 6|50 Ray Tracing 6|48 General Transformation 7|20 Generate Building 3|39 Generate Rays 5|5 Generate Tiles 6|304 Geodetic Transformation 7|18 Median Strip 7|19 Source Coordinates 7|19 Target Coordinates 7|19 Geometry 4|21 GML 7|71 GoogleEarth 13|71 KML-File 13|73 KMZ-File 13|73 GoogleEarth see Import from 10|12 Graphics Bitmap 10|1 Coordinate Grid 9|7 print 13|35 Settings for Objects with Frames 9|61 Template Files 13|45 update during drag 9|5 Vector graphics 10|1 Grid Arithmetics 5|41 Calculation 5|39 Conflict Maps 15|25 Delete 5|19 CadnaA - Reference Manual Index XXIII Evaluation 15|27 from Iso-dB-lines 5|51 Resample 5|22 Specification 5|25 vertical grid 5|57 Grid Appearance Section "Color Palettes" 5|31 Grid Arithmetics 5|59 Grid Calculation Canceling 5|40 Resuming 5|40 Grid interpolation 6|45 Grid of Receivers 5|17 Ground Absorption Ground Absorption Areas 3|63 Ground Absorption Areas 3|63 Groups Hierarchy of Groups 14|24 Partial Sound Level 14|27 H HAP-Calculation 6|275 Height of Parapet left/right 2|87 Height Points 4|15, 4|17 Delete Height Points, Multifile 15|55 generate cluster from bitmap 4|63 Import ASCII-file 4|17 Hold Value 9|69 I Import 4|17 Allocate Object type to layer 7|5 Format 7|35 formats 7|35 Height Points 7|95 CadnaA - Reference Manual Importing in Section only 7|7 Importing selected Object Types 7|11 Layer 7|1 MITHRA 7|89 Mithra Trains 7|89 NMPB08 Trains 7|89 Number of Trains 7|113 ODBC 7|115 Options 7|1, 7|3 QSI 7|89 T-Mobil 7|89 Import / Export Number of Trains 7|113 Import format CityGML 7|71 GML 7|71 Import formats ArcView 7|39 ASCII-Objects 7|99 Atlas Gis 7|43 AtlasGIS 7|43 AutoCad-DXF 7|45, 7|47, 7|49 Bitmap 7|89 Building Height points 7|97 CadnaA 7|37 CST 7|91 EDBS 7|69 MapInfo 7|85 NTF 7|89 Slip 7|89 SOSI 7|89 special formats 7|89 Stratis 7|91 third-party software 7|111 WINPUT 7|95 Import old Palette-File 5|36 Import Options Affine Transformation 7|17 XXIV Index Allocate object type to layer 7|5 General Transformation 7|20, 7|22 Import only Section 7|7 Importing selected Object Types 7|11 Inclined Sources 2|13 Individual Assignment of Objects 14|9 Industrial source horizontal area source 2|4 Line Source 2|3 Point Source 2|3 vertical area source 2|4 Industrial source dialog directivity index 2|25 Emission value A-weighted 2|11 K0 w/o ground 2|25 normalized A 2|16 radiating area (m²) 2|20 Industry Tab 6|87 Industry tab 6|87 relative humidity 6|105, 6|113, 6|119, 6|130, 6|134, 6|143, 6|152 Wind Speed for Chimney Directivity 6|113, 6|130 information on terrain models 6|73 Insert Bitmaps 10|5 Interpolation of height z 7|21 K KML-File 13|73 KMZ-File 13|73 L Labeling of Printing Ranges 13|47 LAFmaxX% 6|172 Land Use 5|13, 5|15 Lateral Diffraction 6|93, 6|94, 6|111, 6|151 Lateral Slope 2|82 Layer (for Import) 7|1 Level Box 9|69 Level Range 5|35 Level, Specifying Precision 5|8 Level-Difference-Map Building Noise 5|83 LfU-Study (2007) 2|277 Libraries Absorption Spectra 12|27 global placed on server 12|3 user-defined data 12|3 Libraries Manager 12|79 Lift Sources to Ground-Niveau 6|73 Limits Background 9|3 calc 9|3 Line of Fault 4|19 Line to Point see Text Box Lines of Equal Sound Level 5|32 Local Train List 2|193, 2|210, 2|216, 2|249 Long Straight Road 2|99 Lower/Upper Limit 5|35 M MapInfo 7|85 Margins 13|24 Marker size 9|99 Match Points 7|15 max. Error 6|35 Median Strip 7|19, 9|12 menu File|Database 7|115 MicroStation-DGN 7|45 min. Dist. Source - Reflector 6|85 Miscellaneous Background beyond the Limits 9|100 CadnaA - Reference Manual Index XXV Marker size 9|99 Segment Length 9|100 Update during Calculation of Grid 9|100 Update during Drag 9|100 MITHRA 7|89 Mithra Compatibility 6|50 Model of Terrain Area sources follow terrain 6|74 Explicit Edges Only 6|72 general information 6|73 Lift Sources to Ground-Niveau 6|73 Triangulation 6|71 Modify Objects ObjectTree 14|13 Monetary Evaluation BUWAL 15|37 Mouse transform objects s. objects Multifile 15|55 Multiple Source Effect 6|275 Multithreading 6|273 N Noise Map PCSP 6|303 Noise Maps of Buildings 5|69 Noise Source Optimisable Source 2|299 Nord 96 (Road) LAFmaxX% 6|172 Sampling Interval (s) 6|172 normalized A 2|16 NTF 7|89 NTv2 reference systems 7|18, 9|11 Number of Trains 7|113 CadnaA - Reference Manual O Object Appearance 9|13 3D tab 9|39, 9|49 Fill tab 9|31 Fill with Hatch tab 9|37 Fill with Symbols tab 9|33 General tab 9|21 Line of Symbols tab 9|29 Line tab 9|27 Symbol tab 9|25 Objects Tables 11|3 transform using the mouse 7|22 with frames 9|61 Objects’s Geometry 4|21 Object-Scan 15|3 ObjectTree Assigning Objects 14|9 Auto-Assignment of Objects 14|9 Copying Objects 14|12 Deactivated Objects 14|10 Definition 14|3 Definition and Editing 14|8 Example 14|8 Indiv. Assignment of Objects 14|9 Modify Objects 14|13 Partial Level 14|12 Sound Power Level 14|11 Obstacles 3D-Reflector 3|71 Barrier 3|41 Bridge 3|61 Building 3|3 Built-Up Areas 3|65 Cylinder 3|69 Embankment 3|87 XXVI Index Foliage 3|65 ground absorption areas 3|63 reflection properties 3|1 Obstacles in Area Source not Shield 6|103, 6|112 ODBC interface 7|115 Offset 9|12 Offset-Values 9|12 Operating Time 2|21 Optimisable Source 2|299 Usability Function 2|302 Optimisable Source Tab 6|251 Optimized Area Sources 2|299 Option XL 15|1 closing buildings 15|49 Evaluation 15|27 Facade points 5|77 Monetary Evaluation BUWAL 15|37 Object-Scan 15|3 Population Density 15|33 Options Coordinate Grid 9|7 for 3D-Symbols 9|73 Land Use 5|15 P Palette Entry 12|69 Parking Lot LfU-Study (2007) 2|277 RLS-90 2|275 SN 640 578 2|285 Partial Levels 5|11 Partial Sound Level 14|24, 14|27 Partition Tab 6|51 RBLärm 92, method 1 6|54 Pass-by level for line sources 2|289 video 2|298 paste 11|9 PCSP 6|303 Generate Tiles 6|304 User-defined Tiling 6|305 PDF s. Bitmap, convert Population Density 15|33 Precision of Levels 5|8 Preview 13|51 Zoom 13|51 Print Preview 13|51 Print Graphics 13|35 Reports 13|41 Template Files 13|45 Printing Reports 13|41 Template Files 13|45 Printing Reports 13|41 Program Controlled Segm. Processing 6|303 Progressive Colors 5|35 Projection with large sources 6|9 Protocol 6|259 Purge Tables 12|81 Q QSI Import 7|89 Statistical Analysis 6|282, 6|289 R radiating area (m²) 2|20 Railroad Tab 6|215 Railway 2|179 CadnaA - Reference Manual Index XXVII traffic-count calculator 2|269 train classes user-defined 2|255 Raster factor 6|51 Ray Tracing 6|48 Rays see Generate Rays RBLärm 92, method 1 6|54 Receiver 5|3 Check Consistency 5|9 Generate Rays 5|5 suppress empty partial levels 5|12 Receiver Grid 5|17 Reference Time Tab 6|59 Reflection 6|13 Absorption coefficient alpha 3|2 Configuration tab 6|77 of the 1st Order 6|15 Properties of Obstacles 3|1 Reflection Tab 6|77 Reflections of Higher Order 6|19 relative humidity 6|105, 6|113, 6|119, 6|130, 6|134, 6|143, 6|152 Resample (Grid) 5|22 Result Table Building Noise 5|79 Edit 11|25 Resuming Grid Calculation 5|40 Rich Text Format (RTF) 13|67 RLS-90 2|275 Road 2|73 Average Height (m) 2|94, 2|165 Calc Width of Roads 2|95 curb-to-curb 2|75 Distance (m) 2|94, 2|165 Distance of the outer lanes 2|75 Emission Lm,E 2|82 Gradient (%) 2|84 CadnaA - Reference Manual Road Width 2|75 Speed 2|84 Station Mark 9|77 Traffic Density 2|82 Traffic Lights 2|171 widening from 1 to 2 lanes 2|78 widening of lanes 2|78 width, curb-to-curb 2|75 Road Tab 6|159 Road Type 2|82 road width, curb to curb 2|75 roof bitmap 3|27 roof bitmaps texture alignment 3|27 Roof Edge see Crowning Rotation and Displacement 7|14 RTF 13|67 S Sampling Interval (s) 6|172 Saving 14|41 Scale Vertical Grid 5|58 Scale Dimension 9|65 Search Radius (m) 6|38 Search Radius for Reflectors 6|79 Section 9|59 Segment Length 9|100 segmentation RB-Lärm 92, method 1 6|54 Selecting Data for the Calculation 6|257 Self-Screening 2|187 Station from/up to 2|88 Shape 13|57 sigma 6|42 Slip 7|89 SN 640 578 2|285 XXVIII Index Snap Point to Building Facade 3|17 Sorting columns 11|7 Sosi 7|89 Sound Power Level 2|11 Sound Rays 6|23 and Reflection 6|3 from extended Sources 6|7 from Point Sources 6|5 Source Coordinates 7|19 Source dialog Steady-State 2|21 Special Calculations 6|275 Special Formats 7|89 Spectra Absorption-Spectra 12|27 Diagram 2|11 Spectrum Monitor 2|11 Speed 2|84 Speed Limit 2|84 Standard Deviation 6|42 Standard Height 6|71 Station from/up to see Self-Screening Station Mark 9|77 Status bar Information 9|5 Storeys string variable 5|81 Stratis 7|91 Strictly according to Schall 03 6|221 String variable for Building Noise Map 5|82 substitute level acc. to VDI 3722-2 6|275 Symbol 9|71 Main Aspect Ratio 9|72 Scale Dimensions 9|72 Synchronization 11|4 T Table adjusting the column width 11|8 copy & paste data records 11|9 delete Data Record 11|4 sort column 11|7 Tables 11|3 purge tables 12|81 Tabs (Object Appearance) 3D 9|39, 9|49 Fill 9|31 Fill with Hatch 9|37 Fill with Symbols 9|33 Line 9|27 Line of Symbols 9|29 Symbol 9|25 Tabs(Object Appearance) General 9|21 Target Coordinates 7|19 Temperature 6|105, 6|113, 6|119, 6|130, 6|134, 6|143, 6|152 Template Files 13|45, 13|46 Labeling of Printing Ranges 13|47 Tennis source 2|67 Text block how to enter a 12|64 Text Box 9|63 display in 3D 9|89 Line to Point 9|66 Third-Party Software 7|111 Tiling a Project 6|303 T-Mobil 7|89 Topography 4|1 Building Height Points 7|97 CadnaA - Reference Manual Index XXIX Contour Lines 4|11 Fault Lines 4|19 Height Points 4|15 Traffic Lights 2|171 Traffic-Count Calculator 2|269 Train Classes and Penalties 2|182 Train Classes User-defined 2|255 Transformation 7|13 Affine Transformation 7|17 Directivity vector 7|13 General Transformation 7|20 Geodetic Transformation 7|18 Interactive Transformation 7|22 Interpolation of height z 7|21 Match Points 7|15 Rotation and Displacement 7|14 Transforming Bitmaps 10|10 Transparency acoustic (%) 3|11 Bitmap 10|9 Triangulation 6|71 TXT 13|67 U Uncertainty 6|41 Update automatically/ Hold Value 9|69 Update during Calculation of Grid 9|100 Update during Drag 9|5, 9|100 Usability Function 2|302 User-defined coordinate system 9|12 V VDI 3722-2 see Multiple Source Effect 6|275 Vector graphics 10|1 Vertical Grid 5|57 CadnaA - Reference Manual Grid Arithmetics 5|59 Scale 5|58 Video 2|298 View see Import from GoogleEarth 10|13 W Web-Bitmaps 10|19 Wind Speed for Directivity 6|113, 6|130 WINPUT-DGM 7|95 XXX Index CadnaA - Reference Manual Chapter 1 - Introduction Chapter 1 - Introduction CadnaA is a software program for the calculation and the assessment of noise and air pollution. The program fulfills the requirements for professional experts. The software calculates and predicts the noise immission in the neighborhood of: • • commercial and industrial sites, sports and leisure facilities, and of traffic systems like • • • road and railways, airports and landing strips, or any other noisy facilities. CadnaA is suitable for noise prediction in local studies as well as for detailed analyses of mapping noise scenarios in large cities (option CadnaA-XL). Powerful features include incredible screen displays, handling and output of graphical grids and the use of scanned bitmap plans (option CadnaA-BMP). CadnaA enables automatic optimization of barriers and the automatic allocation of noise quota (option CadnaA-BPL). Aircraft noise in the vicinity of airports, landing strips and related facilities is calculated with the additional option CadnaA-FLG. The option CadnaA-APL („Air Pollution“) extends the range of application to the calculation, the assessment, and the presentation of air pollutants distribution. Basic to all, CadnaA has the ability to import and export data from and to third-party software (e.g. ArcView, MapInfo, DXF, or from databases via the ODBC-interface). CadnaA - Reference Manual 11 1 2 1 1 Chapter 1 - Introduction The sound level during pass-by’s with time history and auralization of moving sources, the different 3D-views of your project when moving through, the PCSP (Program Controlled Segmented Processing) to accelerate calculation of large projects, the groups and the ObjectTree are just some highlights of CadnaA. CadnaA - Reference Manual 13 Chapter 1 - Introduction 1.1 Structure of CadnaA documentation 1.1 Structure of CadnaA documentation 1 The range of documentation provided with the CadnaA software consists of the following parts: Document Contents Introduction installation, editing of objects, modes of calculation, modeling industrial, road, and railway noise, basic import features & grouping concept, Modify Objects & context menu actions/ commands Reference manual (present manual) detailed description of all dialogs and their options (sources, obstacles, topography, immission), configuration dialog, import/export, graphics/bitmaps, tables & libraries, project organization manual „Attributes, Variables, and Keywords“ listings of object attributes, variables & keywords, handling of string operations, operators & functions, protocol abbreviations These documents are revised with every new release of CadnaA regarding new features and also with respect to modifications or amendments of existing features. The reference manual contains the documentation and description of all CadnaA features, excluding the installation procedure, the input and the editing of objects, and the actions/commands on the dialog Modify Objects and on the context menu. Those features are explained in the introductory manual besides an introduction to all modes of calculation and all noise types. CadnaA - Reference Manual Structure of this manual 4 1 1 Chapter 1 - Introduction 1.1 Structure of CadnaA documentation Chapter 2 describes for each source type all available options on the corresponding object dialog, including short examples if necessary. The subchapters for each source type (industry, road, railway) start by a chapter explaining input data independent from the selected standard, followed by standard-specific explanations. Due to numerous standards and guidelines implemented in CadnaA, and with respect to the possible revision of national procedures between two software releases, DataKustik cannot guarantee in any case the actuality of the specifications given. Particularly, the specifications cannot substitute buying and studying the original paper. Indications on the official supplier can be found in the references (chapter 1.4 "Literature"). In chapter 3 to 4, the reference manual treats all obstacles including the topography. In chapter 5 all types of noise evaluation in CadnaA are described. This includes: the receiver point, the area of designated, the horizontal and the vertical grid as well as the building evaluation. This chapter treats also the features of the option XL as there are, e.g.: the map of conflicts, the grid evaluation, the ObjectScan, and the population density. Chapter 6 presents the principles of calculation applied in CadnaA, particularly with respect to the configuration settings. In Chapter 6, the basic principles of the calculations in CadnaA are explained. Furthermore, you will find here the description of the standardspecific configurations of calculation. The text is specific to each source type with separate chapters for each implemented calculation procedure. In addition, the other commands and features on the Calculation menu are described (e.g. multi-threading and batch operation by using PCSP.). The chapter 7 covers the handling of all import formats available in CadnaA. Chapter 8 treats the use of a digitizing board for the input of object geometry. CadnaA - Reference Manual Chapter 1 - Introduction 1.1 Structure of CadnaA documentation The chapters 9 and 10 describe all available objects and procedures for producing a graphic output in CadnaA, as well as the features for import and scaling of external bitmaps. Chapter 11 explains the features of the object’s tables while chapter 12 covers their application within the local and global libraries. The chapter 13 deals with the output of report files (for example as tables) or as a graphic printout using the CadnaA-PlotDesigner. This includes the export of geo-referenced projects to GoogleEarth™. Chapter 14 deals with all aspects of project organization. This includes the ObjectTree, used to define groups and the handling of variants. In Chapter 15, the further features for evaluation provided by the options X and XL are described (e.g. object scanning, conflict maps, grid evaluation, population density). This includes also the features „Close Polygons“ and „Delete Height Points“. Further, this chapter describes the features and commands of the scripting language Lua in CadnaA. CadnaA - Reference Manual 15 1 6 1 Chapter 1 - Introduction 1.1 Structure of CadnaA documentation 1 CadnaA - Reference Manual 17 Chapter 1 - Introduction 1.2 New Features of CadnaA 2018 1.2 New Features of CadnaA 2018 1 The list of new features offered by CadnaA 2018 is subdivided into the following sections: • • • • • • • Calculation/Configuration CadnaA-Objects Further New Features Miscellaneous Import/Export CadnaA-Options Bug Fixing • ISO 9613: new type "Ground Absorption": "WEA interim (Agr=-3 dB)" used by German Interim method for Wind Turbine Predictions (2015) • Railway ONR 305011, Semibel, FTA/FRA: new option "Calc maximum Pass-By-Level" (based on Leq-based emission per unit length) • Road Nordic Prediction Method (1996): new option "Threshold" with calculation of maximum Pass-By-Level to calculate NATs (Number above Threshold) • "Evaluation Parameters" tab: selecting "f(x)" offers new parameters Lden/Ln for evaluations acc. to VDI 3722 • dialog "Multiple Source Effect" (Calculation menu): new option "Save total in (Variant)" for sum-grid acc. to VDI 3722 • grid calculation per batch for all variants (using CALC_RASTER=2, not for PCSP) • Point, Line, Area Sources: new attribute TEINW_GANG (selects a diurnal pattern) • object "Symbol": new scale bars available • Building Evaluation: dialog Exclude Facades now accepts up to 256 facades CadnaA - Reference Manual Calculation|Configuration CadnaA-Objects 8 1 1 Further New Features Chapter 1 - Introduction 1.2 New Features of CadnaA 2018 • Bitmap: new option "Bitmap in internal memory" svaes the bitmap as part of the CadnaA file • Bitmap: extended transparency features (e.g. by specifying transparency and "white is transparent globally") • Road (CNOSSOS-EU): attribute STRO_ID selects road surface (e.g. CNS_01 .. CNS_15) • Facade Points: new attribute FAC_EINW_xy (weighted per facade length or not, all or just active ones) • Railway (Schall03-2014, CNOSSOS-EU, NMPB08-Fer): new attributes GEFAELLE, MIND, MIND_I, SLAB_TRACK • new graphical user-interface: scalable object icons (on toolbox and on toolbar) scalable font in dialogs (Options|Miscellaneous menu) • dialog ObjectTree|Definition: button "Sync. Graphics" on ObjectTree toolbar • new context menu command "Import here...": The origin (0,0) of the imported data is placed at the coordinates of a point object or were the mouse click occured. • Grid Arithmetics: now with access to grids in variants (coding: RxVvvEvalParaNo, x=0..6, vv=01..16, EvalParaNo=1..4) • Multithreading (Calculation menu): offers now up to 64 threads (requiring 64-Bit option) • command/action "Parallel Object": new option "Distance from curb/ border" for road and railway considers a specified additional width (dialog Appearance/Road or on road's geometry) • dialog Modify Objects, new action "Break Lines": just breaks line/area objects of the selected object type • dialog Modify Objects: conditions for string possible • geodetic transformation: offers now NTv2 reference systems (requires that the respective gsb-files are copied to directory <cadnadir>/NTv2) CadnaA - Reference Manual 19 Chapter 1 - Introduction 1.2 New Features of CadnaA 2018 • dialog Building Noise Map (Options menu): new options "Facade points acc. to VBEB" and "... acc. to CNOSSOS" • Grid|Delete menu: Holding CTRL key depressed deletes all grids in variants. • dialog Modify Objects: With action "Delete" now default condition match(ID$, "RAY*") deleting all rays • extended keyword #(File, ...): #(File, dpne).cna_autosave generates an autosave-file • screen scaling uses "DPI aware" for all monitors: makes fonts and icons bigger and easier to read • import formats "SOSI" and "CityGML": new option "Unknown Attributes to Memo-Variables"" • new export format DOCX: exports reports based on MS-Word template DOCX (new, table specific keywords #(CUSTOM_TABLE, ...) and #(COL, ...) • PlotDesigner (File|Print Graphics menu): new "Preview" button • printing the graphics per template file (File menu) still available for existing graphics template files • Result Table: new string variable FAC_LEN, facade length per facade point • option X/XL: new and extended LUA commands (e.g. import, grid spacing, Exclude Facades, 3D-Special) • option FLG: new calculation procedure ECAC4 • option FLG: selectable no. of corridor paths with ECAC3 and ECAC4 • option 64-Bit: multithreading now for up to 64 threads CadnaA - Reference Manual 1 Miscellaneous Import/Export CadnaA-Options 10 1 1 Bug Fixing Chapter 1 - Introduction 1.2 New Features of CadnaA 2018 • NMPB08-Fer: vertical directivity corrected (no absolute value), toggle back per local text block OPT_OLD_CALC with text: nmpb08_vdir_abs_x157 • Concawe: ground absorption K3 now just consider ray path length across absorbing round CadnaA - Reference Manual Chapter 1 - Introduction 1.3 Notations 1.3 Notations 1 The following table comprises all types of notations used in the CadnaAdocumentation. setup text to be typed in RETURN, CTRL, DEL keyboard keys CTRL+v key combinations (e.g.: hold down the CTRL-key while typing the letter v) down arrow key arrow keys (move cursor to left/right/up/down) Program Files/Datakustik directories Grid|Appearance, 3D-Special menus and commands „Geometry“, „TransLoss“ buttons in dialogs and other options in dialogs double-click, double-clicking Instructs you to rapidly press and release the left mouse button twice. • The focal point requires an action or a sequence of actions. remark or comment Examples\ reference to file, use the indicated file path to open the file 04_Topography\HP.cna CadnaA - Reference Manual 1 11 12 1 Chapter 1 - Introduction 1.3 Notations 1 CadnaA - Reference Manual 1 13 Chapter 1 - Introduction 1.4 Literature 1.4 Literature 1 Standards & Guidelines /1/ Concawe-report no. 4/81, „The propagation of noise from petroleum and petrochemical complexes to neighboring communities“, (Ref.AT 931), CONCAWE, Den Haag May 1981 /2/ AR-INTERIM-CM, Adaptation and revision of the interim noise computation methods for the purpose of strategic noise mapping, Final Report, Part A, Reference: B43040/2001/329750/MAR/C1, 25 March 2003 /3/ IMAGINE Improved Methods for the Assessment of the Generic Impact of Noise in the Environment, WP 7: Industrial noise sources, Adaptation of the Harmonoise engineering model to industrial noise sources, document IMA07MO-041126-CSTB01, Date : 26/11/2004. /4/ HARMONOISE, WP 2, Reference Model, Description of the Reference model, document HAR29TR-041118-TNO10, 22 December 2004. /5/ Development of the HARMONOISE Point-To-Point Model, Prediction of Excess Attenuation in Outdoor Noise Propagation, author: D. van Maercke/CSTB, presented at Meeting Norwegian Acoustical Society, Kristiansand, 08.09.2006. /6/ ECAC DOC 29: European Civil Aviation Conference Document 29, „Report on Standard Method of Computing Noise Contours around Civil Airports“, 2nd edition, 1997 /7/ ISO 3744 Acoustics - Determination of sound power levels of noise sources using sound pressure - Engineering method in an essential free field over a reflecting plane /8/ ISO 9613, Acoustics - Attenuation of sound during propagation outdoors, Part 1 (1993-06): Calculation of the absorption of sound by the atmosphere, Part 2 (1996-12): General method of calculation, ISO International Organization for Standardization, Geneva (CH) /9/ ISO 9614: Acoustics - Determination of sound power levels of noise sources using sound intensity: Part 1: Measurement at discrete points (as of 1993-06-03) Part 2: Measurement by scanning (as of 1996-08-01) Part 3: Precision method for measurement by scanning (as of 2002-10-22) /10/ ISO 717: Acoustics - Rating of sound insulation in buildings and of building elements, Part 1: Airborne sound insulation (ISO 717-1:1996) Part 2: Impact sound insulation (ISO 717-2:1996); ISO International Organization for Standardization, Geneva (CH) CadnaA - Reference Manual International 14 1 1 Germany Chapter 1 - Introduction 1.4 Literature /11/ ISO 11654 (1997), Acoustics - Sound absorbers for use in buildings - Rating of sound absorption, ISO International Organization for Standardization, Geneva (CH) /12/ ISO 3744:2010, Acoustics - Determination of sound power levels and sound energy levels of noise sources using sound pressure - Engineering methods for an essentially free field over a reflecting plane (as of 2010-09-22), ISO International Organization for Standardization, Geneva (CH) /13/ ISO 3745:2012, Acoustics - Determination of sound power levels and sound energy levels of noise sources using sound pressure -- Precision methods for anechoic rooms and hemi-anechoic rooms (as of 2012-03-16), ISO International Organization for Standardization, Geneva (CH) /14/ ISO 3746:2010, Acoustics - Determination of sound power levels and sound energy levels of noise sources using sound pressure -- Survey method using an enveloping measurement surface over a reflecting plane (as of 2010-11-25), ISO International Organization for Standardization, Geneva (CH) /15/ EN 12354: Building Acoustics - Estimation of acoustic performance of buildings from the performance of products, Part 1 (1999): Airborne sound insulation between rooms; Part 2 (1999): Impact sound insulation between rooms Part 3 (1999): Airborne sound insulation against outdoor sound /16/ COMMISSION DIRECTIVE (EU) 2015/996 of 19 May 2015 establishing common noise assessment methods according to Directive 2002/49/EC of the European Parliament and of the Council, ANNEX Assessment Methods for the Noise Indicators, Official Journal of the European Union L168, Legislation Volume 58, 1 July 2015 /17/ RLS90, Richtlinien für den Lärmschutz an Straßen (Guidelines for Noise Control at Roads, in German); Der Bundesminister für Verkehr, Abteilung Straßenbau, Ausgabe 1990, Verkehrsblatt 44 (1990) /18/ Richtlinien für die Anlage von Straßen RAS (Guidelines for the construction of roads, in German), Teil: Querschnitte RAS-Q Ausgabe 82, Forschungsgesellschaft für Strassen- und Verkehrswesen, Arbeitsgruppe Strassenentwurf /19/ Richtlinien für die Anlage von Straßen RAS (Guidelines for the construction of roads, in German), Teil: Querschnitte RAS-Q 96, Forschungsgesellschaft für Strassen- und Verkehrswesen, Arbeitsgruppe Strassenentwurf /20/ Rechenbeispiele zu den Richtlinien für den Lärmschutz an Straßen RBLärm-92 (Calculation Examples concerning the Guidelines for Noise Control at Roads, in German), Der Bundesminister für Verkehr Abteilung Straßenbau, Ausgabe 1992 /21/ Entwurfshinweise für planfreie Knotenpunkte an Straßen der Kategoriengruppe B, RAS-K-2-B, Ausgabe 1995. /22/ Aktuelle Hinweise zur Gestaltung planfreier Knotenpunkte außerhalb bebauter Gebiete, AH-RAL-K-2, Ausgabe 1993. CadnaA - Reference Manual Chapter 1 - Introduction 1.4 Literature /23/ Schall 03, Richtlinie zur Berechnung der Schallimmissionen von Schienenwegen (Guidelines for the Calculation of Sound Immission from Railways, in German), Akustik 03, Ausgabe 1990, Deutsche Bundesbahn, Bundesbahn-Zentralamt München /24/ Aktuelle Information des BZA München - Akustik, Einfluss von Radabsorbern, 016, 103.10313, 962/6302, vom 19.4.1991 /25/ Aktuelle Information des BZA München - Akustik, Schall 03; Aerodyn. Einflüsse, 021, 103.10313, 962/6302 vom 17.8.1991 /26/ Verordnung zur Änderung der Sechzehnten Verordnung zur Durchführung des Bundes-Immissionsschutzgesetzes (Verkehrslärmschutzverordnung - 16. BImSchV) vom 18. Dezember 2014 (BGBl Teil I Nr. 61, S. 2269-2313 vom 23.12.2014). /27/ AzB 1975 - Bekanntmachung der Datenerfassungssysteme für die Ermittlung von Lärmschutzbereichen an zivilen (DES) und militärischen Flugplätzen (DES-MIL) sowie einer Anleitung zur Berechnung, Der Bundesminister des Innern, GMBl. Ausg. A, S.125, 1975 /28/ AzB 2008 - Verordnung über die Datenerfassung und das Berechnungsverfahren für die Festsetzung von Lärmschutzbereichen vom 27. Dezember 2008 (BGBl. I S. 2980) /29/ DIN 824 (1981-03): Technische Zeichnungen; Faltung auf Ablageformat (Technical drawings - Folding to filing size, in German), Beuth Verlag, Berlin /30/ DIN 18005, Teil 1 (1987-05) Schallschutz im Städtebau - Berechnungsverfahren (Noise abatement in town planning - Calculation Methods, in German), Beuth Verlag, Berlin /31/ DIN 18005, Teil 2 (9/91) Schallschutz im Städtebau, Lärmkarten - Kartenmäßige Darstellung von Schallimmissionen (Noise abatement in town planning - Representation of noise levels on noise maps, in German), Beuth Verlag, Berlin /32/ DIN 45684-1 (2006-09), Ermittlung von Fluggeräuschimmissionen an Landeplätzen, Teil 1: Berechnungsverfahren (Calculation of Noise Contours at Landing Sites, in German), Beuth-Verlag, Berlin /33/ DIN 45687 (2006-05), Akustik, Software-Erzeugnisse zur Berechnung der Geräuschimmission im Freien, Qualitätsanforderung und Prüfbestimmungen (Software-products for the calculation of noise outdoors, requirements and evaluation, in German), Beuth-Verlag, Berlin /34/ DIN 45691(2006-12), Geräuschkontingentierung (Noise Allotment, in German), Beuth-Verlag, Berlin /35/ DIN 52210, Bauakustische Prüfungen Luft- und Trittschalldämmung - Meßverfahren /36/ VDI guideline 2058, Blatt 1, Beurteilung von Arbeitslärm in der Nachbarschaft (Assessment of working noise in the vicinity, in German), Sept. 1985, Beuth-Verlag, Berlin /37/ VDI guideline 2571, Schallabstrahlung von Industriebauten (Sound radiation from industrial buildings, in German), August 1976, Beuth-Verlag, Berlin CadnaA - Reference Manual 1 15 1 16 1 1 Chapter 1 - Introduction 1.4 Literature /38/ VDI guideline 2714, Schallausbreitung im Freien (Outdoor sound propagation, in German), August 1988 (withdrawn) /39/ VDI guideline 2719, Schalldämmung von Fenstern und deren Zusatzeinrichtungen (Sound Insulation by Windows, Ventilation devices etc., in German), August 1987, Beuth-Verlag, Berlin /40/ VDI guideline 2720 part 1, Schallschutz durch Abschirmung im Freien (Noise control by barriers outdoors, in German), March 1997, Beuth-Verlag, Berlin /41/ VDI guideline 3760, Berechnung und Messung der Schallausbreitung in Arbeitsräumen (Calculation and measurement of sound propagation in workrooms, in German), Februar 1996, Beuth-Verlag, Berlin /42/ VDI guideline 3770, Characteristic noise emission values of sound sources, Facilities for recreational and sporting activities, April 2002, Beuth Verlag, Berlin /43/ VDI guideline 3733 „Geräusche bei Rohrleitungen“ (Noise at Pipes), July 1996, Beuth Verlag Berlin /44/ VDI 3722, Effects of traffic noise, Part 2: Characteristic quantities in case of impact of multiple sources, 05-2013, Beuth Verlag Berlin /45/ Reinicke, W., J. Danner: Schallabstrahlung von Schornsteinen, Messung und technische Möglichkeiten zu ihrer Minderung. UBA-Texte 17/1981, UBA-Forschungsbericht 105.03.301, Berlin, November 1981 /46/ VDI guideline 3945 part 3: Environmental meteorology - Atmospheric dispersion models - Particle model, Ed.: Kommission Reinhaltung der Luft im VDI und DIN Normenausschuss KRdL, September 2000 /47/ TAL98 - Zur Bestimmung der meteorologischen Dämpfung - Eine Anleitung mit Beispielen - Landesumweltamt NRW, Postfach 102363, D-45023 Essen /48/ MLus 92, Ausgabe 96, Merkblatt über Luftverunreinigungen an Straßen - Teil: Straßen ohne oder mit lockerer Randbebauung, Ausgabe 1991, Geänderte Fassung 1996, Forschungsgesellschaft für Straßen- und Verkehrswesen e.V., Köln, Arbeitsgruppe Verkehrsführung und Verkehrssicherheit. /49/ Parking Lot Study 1993, Ed.: Bayerisches Landesamt für Umweltschutz LfU (Bavarian Environmental Agency), München 1993 /50/ Parking Lot Study 1995, Ed.: Bayerisches Landesamt für Umweltschutz LfU (Bavarian Environmental Agency), November 1994 /51/ Parking Lot Study 2003, 4th edition, volume 89, Ed.: Bayerisches Landesamt für Umweltschutz LfU (Bavarian Environmental Agency), Augsburg 8/2003 /52/ Parking Lot Study 2007, 6th edition, Ed.: Bayerisches Landesamt für Umwelt, Augsburg 2007. CadnaA - Reference Manual 1 17 Chapter 1 - Introduction 1.4 Literature /53/ ÖAL-Richtlinie 24, Blatt 1 und 2 (Ausgabe 2008-03-01): Lärmschutzzonen in der Umgebung von Flughäfen, Planungs- und Berechnungsgrundlagen (Noise protection zones in the vicinity of airports - planning and calculation, in German), Ed.: Österreichischer Arbeitsring für Lärmbekämpfung, Wien. /54/ ÖAL-Richtlinie Nr. 28, Schallabstrahlung und Schallausbreitung (Sound Radiation and Sound Propagation, in German), Dezember 1987, & Erläuterende Ergänzung, Februar 2001, Ed.: Österreichischer Arbeitsring für Lärmbekämpfung, Wien /55/ Ergänzung zur ÖAL-Richtlinie Nr. 28, (Amendment to ÖAL guideline 28) Februar 2001, Hrsg.: Österreichischer Arbeitsring für Lärmbekämpfung, Wien. /56/ ÖNORM ISO 9613-2:2008, Akustik, Dämpfung des Schalls bei der Ausbreitung im Freien, Teil 1 (1993-06): Berechnung der Schallabsorption durch die Luft, Teil 2 (1996-12): Allgemeines Berechnungsverfahren, Beuth Verlag Berlin. /57/ ONR 305011:2004-09-01, Berechnung der Schallimmission durch Schienenverkehr Zugverkehr, Verschub- und Umschlagbetrieb (Noise immission by railway traffic, in German). /58/ ONR 305011:2009-11-15, Berechnung der Schallimmission durch Schienenverkehr Zugverkehr, Verschub- und Umschlagbetrieb (Noise immission by railway traffic, in German). /59/ RVS 3.02 Lärmschutz (Dezember 1997), Ed.: Forschungsgesellschaft für das Verkehrund Straßenwesen (FVS) Wien. /60/ RVS 04.02.11 Lärmschutz (März 2006), Ed.: Forschungsgesellschaft für das Verkehrund Straßenwesen (FVS) Wien. /61/ Amendment for RVS 04.02.11 Lärmschutz, edition March 2006 (April 2008), Ed.: Forschungsgesellschaft für das Verkehr- und Straßenwesen (FVS) Wien. /62/ forum Schall: Anleitung für die Modellbildung zur Schallimmissionsprognose nach NORM ISO 9613-2:2008 und ÖNORM EN 12354-4:2001-02-01, Hrsg.: Umweltbundesamt/Lebensministerium, Wien 2011 /63/ Schriftenreihe Umweltschutz Nr. 57: Anleitung zur Ermittlung und Beurteilung von Lärmimmissionen an Strassen, Ed.: Bundesamt für Umweltschutz, Bern, Januar 1987. /64/ Schriftenreihe Umweltschutz Nr. 60: Computermodell zur Berechnung von Strassenlärm, Teil 1: Bedienungsanleitung zum Computerprogramm StL-86, Ed.: Bundesamt für Umweltschutz, Bern, März 1987. /65/ Mitteilung zur Lärmschutz-Verordnung (LSV) Nr. 6 (1995): Strassenlärm: Korrekturen zum Strassenlärm-Berechnungsmodell, Bundesamt für Umwelt, Wald und Landschaft, Bern. CadnaA - Reference Manual Austria Switzerland 1 18 1 1 Scandinavia France Chapter 1 - Introduction 1.4 Literature /66/ SN 640 578:2006-07, Lärmimmissionen von Parkierungsanlagen - Berechnung der Immissionen. /67/ Leitfaden Strassenlärm. Vollzugshilfe für die Sanierung. Stand: Dezember 2006, Umwelt-Vollzug Nr. 0637, Bundesamt für Umwelt BAFU und vom Bundesamt für Strassen ASTRA Bern, 2006. /68/ Schriftenreihe Umweltschutz Nr. 116: SEMIBEL, Version 1, Schweizerisches Emissions- und Immissionsmodell für die Berechnung von Eisenbahnlärm, Ed.: Bundesamt für Umwelt, Wald und Landschaft, Bern, März 1990. /69/ Schriftenreihe Umwelt Nr. 301, Lärm: Wirtschaftliche Tragbarkeit und Verhältnismässigkeit von Lärmschutzmassnahmen; Bundesamt für Umwelt, Wald und Landschaft (BUWAL) Bern, 1998. /70/ Schriftenreihe Umwelt ; Nr. 366, Lärm: SonRoad - Berechnungsmodell für Strassenlärm, Ed. vom Bundesamt für Umwelt, Wald und Landschaft BUWAL; Bern, BUWAL, 2004. /71/ Environmental noise from industrial plants - General prediction method. Danish Acoustical Laboratory, The Danish Academy of Technical Sciences, Report no. 32, 1982. /72/ Railway Traffic Noise - The Nordic Prediction Method, TemaNord 1996:524, Nordic Council of Ministers, Store Strandstraede 18, DK-1255 Copenhagen K, ISBN 92 9120837 X, ISSN 0908-6692. /73/ Road Traffic Noise - Nordic Prediction Method, TemaNord 1996:525, Nordic Council of Ministers, Store Strandstraede 18, DK-1255 Copenhagen K, ISBN 92 91208361, ISSN 0908-6692. /74/ Rapport 6241: „Ljud från vindkraftverk“, Ed.: Naturvårdsverket, Stockholm, Dec. 2001, ISBN 91-620-6241-7. /75/ User’s Guide Nord2000 Road, Editors: Delta, SINTEF, SP, VTT, Document reference AV 1171/06, Hørsholm/DK, May 2006 /76/ Förordning (2015:216) om trafikbuller vid bostadsbyggnader, Svensk författningssamling 2015:216 /77/ NMPB-Routes 96 - Bruit des Infrastructures Routières, méthode de calcul incluant les effets météorologiques, Ed.: Ministère de l’Équipement, du Logement, des Transports er du Tourisme/CERTU/SETRA/LCPC/CSTB, Janvier 1997 (ISBN 2-11-089201-3). /78/ NMPB-Routes-2008 - Methodological guide, Road noise prediction, volume 2: NMPB 2008 - Noise propagation computation including meteorological effects, Ed.: SETRA (Service d'études sur les transports, les routes et leurs aménagements), April 2009 (Référence : LRS 2008-76-069). CadnaA - Reference Manual 1 19 Chapter 1 - Introduction 1.4 Literature /79/ NMPB-Routes-2008 - Guide méthodologique, Prévision du bruit routier, Volume 1: Calcul des émissions sonores dues au trafic routier, Ed.: SETRA (Service d'études sur les transports, les routes et leurs aménagements), April 2009 (Référence Sétra: 0924-1). /80/ NF S 31-133 (February 2011), Acoustics, Outdoor noise, Calculation of sound levels (F: Acoustique, Bruit dans l'environnement, Calcul de niveaux sonores), Association Française de Normalisation (AFNOR), www.afnor.org /81/ Department of Transport, Welsh Office: Calculation of Road Traffic Noise (CRTN), published by: HMSO, London, 1988. /82/ The Department of Transport: Calculation of Railway Noise (CRN), published by: HMSO, London, 1995. /83/ TRL Limited: Converting the UK traffic noise index LA10,18h to EU noise indices for noise mapping, authors: P G Abbott, P M Nelson, Report PR/SE/451/02 [EPG 1/2/ 37] /84/ BS 5228-1:2009 - Code of practice for noise and vibration control on construction and open sites, Part 1: Noise , Ed.: BSI British Standards 2008. /85/ The Highways Agency et al.: Design Manual for Roads and Bridges (DRMB), HA 213/ 08, volume 11 environmental assessment, section 3 environmental assessment techniques, August 2008. /86/ Additional railway noise source terms for “Calculation of Railway Noise 1995”, report produced for Defra by AEAT, published by the Department for Environment, Food and Rural Affairs, January 2007. /87/ SRM II - Reken- en Meetvorschriften Railverkeerslawaai ‚96, Publikatiereeks Verstoring, Nr. 14/1997, VROM, november 1996 /88/ Miedema: TNO Built Environment und Geosciences, Environement & HEALTH draft TNO report 2005-007 "Rating environmental noise on the basis of noise maps"; Miedema, Henk M.E.; Borst, Hieronymus E., City: Delft; No. 05 6N 013 64041 /89/ TNM - FHWA Federal Highway Administration Model (http://www.trafficnoisemodel.org) TNM Version 2.5, McTrans Center University of Florida, 2088 Northeast Waldo Road, Gainesville, Fl 32609, http://mctrans.ce.ufl.edu /90/ FHWA Traffic Noise Model, Version 1.0, Technical Manual, Final Report, February 1998, Ed.: U.S. Department of Transportation, Federal Highway Administration, FHWA-PD-96-010, DOT-VNTSC-FHWA-98-2 /91/ FTA-report: Transit Noise and Vibration Impact Assessment", Ed.: Office of Planning and Environment, Federal Transit Administration, FTA-VA-90-1003-06, May 2006 (published by Office of Planning and Environment, Federal Transit Administration) CadnaA - Reference Manual 1 United Kingdom (UK) The Netherlands USA 20 1 1 China Chapter 1 - Introduction 1.4 Literature /92/ FRA-report: High-Speed Ground Transportation Noise and Vibration Impact Assessment, HMMH Report No. 293630-4, October 2005 (published by US Department of Transportation, Federal Road Administration) /93/ China State Environmental Protection Standard HJ2.4-2009 (Replacement of HJ/T2.41995): Technical Guidelines for Noise lmpact Assessment, Release on 2009-12-23 implement on 2010-04-01, Released by Ministry of Environmental Protection CadnaA - Reference Manual Chapter 1 - Introduction 1.4 Literature Articles & Reports /94/ Heutschi, K.: SonRoad - Berechnungsmodell für Strassenlärm, Ed.: Bundesamt für Umwelt, Wald und Landschaft BUWAL, Bern, 2004 (Schriftenreihe Umwelt Nr. 366) /95/ Kozak, J., Liberko, M.: Updated Method for Calculation of Road Traffic Noise (in Czech), Annex of the Newsletter of the Ministry of the Environment of the Czech Republic. 1996, No. 3, p.1-16 /96/ Kuttruff, H.: Über Nachhall in Medien mit unregelmäßig verteilten Streuzentren, insbesondere in Hallräumen mit aufgehängten Streukörpern“,Acustica 18 , 1967 /97/ Probst, W.; Donner, U.: Die Unsicherheit des Beurteilungspegels bei der Immissionsprognose (The uncertainty of the sound pressure levels in noise prediction, in German), ZfL 3/2002 Mai, Springer-VDI-Verlag GmbH & Co. KG, Düsseldorf. /98/ Probst, W.: Geräuschentwicklung von Sportanlagen und deren Quantifizierung für Immissionsschutztechnische Prognosen (Noise emission from sports facilities and their quantification with regard to immission prognosis, in German), Bundesinstitut für Sportwissenschaft, Köln, 1994 - Schriftenreihe Sportanlagen und Sportgeräte, B94.2 ISBN 3-921896-84-3 /99/ Probst, W.: „Lärmkontingentierung mit Rechnerunterstützung“ (Computer Aided Noise Allotment, in German), Vortrag bei der Informationsveranstaltung über Qualitätssicherung von Softwareprogrammen, München /100/ Probst, W.: Schallabstrahlung und Schallausbreitung - Berechnungsmodelle und Schallleistungsbestimmung, Forschungsbericht Fb. 556 der Bundesanstalt für Arbeitsschutz, Dortmund 1988 /101/ Probst, W., Neugebauer G., Kurze U., Jovicic S. und Stephenson U.: Schallausbreitung in Arbeitsräumen, Forschungsbericht Fb 621 der Bundesanstalt für Arbeitsschutz, Dortmund 1990 /102/ Probst, W.; Huber, B.: Schallstrahlen und Reflexionen bei der Berechnung der Schallausbreitung mit numerischen Verfahren (Sound Rays and Reflections when calculating Sound Propagation using Numercial Methods, in German), Zeitschrift für Lärmbekämpfung ZfL 44/1997, 143-149 /103/ Probst, W.; Huber, B.: Die Berechnung der Schallemission von Parkhäusern (Calculation of Noise Emission by Multi-Storey Car Parks, in German), Zfl 5/2000, 47. Jhrg. Seite 175 /104/ Probst, W.: Calculation of Noise Levels in an Environment with highly reflecting Objects and Surfaces, Euronoise 1998, München /105/ Probst, W.; Huber B.: Modellierung von Kaminen und akustisch teildurchlässigen Anlagen (Modeling chimneys and acoustically transparent plants, in German), ZfL 49 (2002), No. 4, 144-147, Springer-VDI-Verlag GmbH & Co. KG, Düsseldorf CadnaA - Reference Manual 1 21 1 22 1 1 Chapter 1 - Introduction 1.4 Literature /106/ Probst. W.: Checking of Sound Emission Values, Report Fb 851. Schriftenreihe der Bundesanstalt für Arbeitsschutz, und Arbeitsmedizin, Dortmund/Berlin 1999 CadnaA - Reference Manual Chapter 1 - Introduction 1.4 Literature Legal Acts /107/ Achtzehnte Verordnung zur Durchführung des Bundes-Immissionsschutzgesetzes (Sportanlagenlärmschutzverordnung - 18. BImSchV) vom 18. Juli 1991, Bundesgesetzblatt, Jahrgang 1991, Teil 1, S. 1588 /108/ Sechzehnte Verordnung zur Durchführung des Bundes-Immissionsschutzgesetzes (Verkehrslärmschutzverordnung - 16.BImSchV) vom 12.6.1990. BGBL. IS.1036 /109/ TALärm - Technische Anleitung zum Schutz gegen Lärm, Sechste Allgemeine Verwaltungsvorschrift zum Bundesimmissionsschutzgesetz, 26.8.1998, Gemeinsames Ministerialblatt vom 28.8.1998 /110/ TA-Luft 2002: Erste Allgemeine Verwaltungsvorschrift zum Bundes-Immissionsschutzgesetz (Technische Anleitung zur Reinhaltung der Luft - TA Luft) Vom 24. Juli 2002 (GMBl. 2002, Heft 25 - 29, S. 511 - 605) /111/ 23. BImSchV - Dreiundzwanzigste Verordnung zur Durchführung des Bundes-Immissionsschutzgesetzes (Verordnung über die Festlegung von Konzentrationswerten) vom 16. Dezember 1996 (BGBl. 1 S. 1962) /112/ 22. BImSchV: 22. Verordnung zur Durchführung des Bundesimmissionsschutzgesetzes, 11.September 2002 BGBlI2002, 3626 /113/ VBEB Vorläufige Berechnungsmethode zur Ermittlung der Belastetenzahlen durch Umgebungslärm (German Interim calculation method for the calculation of people annoyed, in German), Stand 28.6.2006 - Entwurf /114/ 003/613/EC: COMMISSION RECOMMENDATION of 6 August 2003 concerning the guidelines on the revised interim computation methods for industrial noise, aircraft noise, road traffic noise and railway noise, and related emission data (notified under document number C(2003) 2807) /115/ Vorläufige Berechnungsmethode für den Umgebungslärm an Straßen (VBUS, German interim calculation method for road noise, in German), Bundesanzeiger, Jahrgang 58, Nr. 154a vom 17. August 2006 /116/ Vorläufige Berechnungsmethode für den Umgebungslärm an Schienenwegen (VBUSch, German interim calculation method for railway noise, in German), Bundesanzeiger, Jahrgang 58, Nr. 154a vom 17. August 2006 /117/ Vorläufige Berechnungsmethode für den Umgebungslärm durch Industrie und Gewerbe (VBUI, German interim calculation method for industrial noise, in German), Bundesanzeiger, Jahrgang 58, Nr. 154a vom 17. August 2006 /118/ Vierundzwanzigste Verordnung zur Durchführung des Bundes-Immissionsschutzgesetzes (Verkehrswege-Schallschutzmaßnahmenverordnung - 24.BImSchV, Bundesgesetzblatt Jahrgang 1997 Teil I Nr. 8, ausgegeben zu Bonn am 12.2.1997 /119/ Magnetschwebebahn-Lärmschutzverordnung vom 23.9.1997 (BGBl. 2329, 2338) CadnaA - Reference Manual 1 23 1 24 1 1 Chapter 1 - Introduction 1.4 Literature /120/ ZTV-Lsw88: Zusätzliche Technische Vorschriften und Richtlinien für die Ausführung von Lärmschutzwänden an Straßen, Verkehrsblatt - Dokument Nr. B 6508 - Vers. 88.2, Der Bundesminister für Verkehr, Abteilung Straßenbau, Verkehrsblatt-Verlag Borgmann GmbH & Co KG, Hohe Straße 39, Hohe Str. 39, 44139 Dortmund /121/ Directive 2002/49/EC of the European Parliament and of the Council of 25th June 2002 relating to the assessment and management of environmental noise, Official Journal of the European Communities, L189/12, EN, 18.7.2002 /122/ Bundesumgebungslärmverordnung - Bundes-LärmV, Jahrgang 2006, ausgeg. 5.April 2006, Bundesgesetzblatt für die Republik Österreich. /123/ Länderausschuss für Immissionsschutz (LAI): Dokumentation zur Schallausbreitung, Interimsverfahren zur Prognose der Geräuschimmissionen von Windkraftanlagen, Fassung 2015-05.1. CadnaA - Reference Manual 21 Chapter 2 - Sound Sources Chapter 2 - Sound Sources 2 Sound sources, the emission of which is described based on the sound power level are called "general sources". In CadnaA, the emission of general sources (such as point, line, and area sources) can be described by single number ratings (sound power level PWL in dB(A)) or by spectra (linear, or with A-, B-, C- or D-weighting) and for the three time periods Day/Evening/Night separately. When both emission types are present within a project, both are included in the calculation at the same time. Within a spectral calculation the sound pressure level or any other evaluation parameter (see chapter 6.2.5) at the receiver point is calculated as a spectrum (linear or A-, B, C- or D-weighted) and as a sum level in dB(A). General Sources Spectra are entered in the local or global libraries (see chapter 12.1), and are referred to in the edit dialog of the source by entering their ID (see manual „Introduction to CadnaA“). The emission parameter of „parametric sources“ is not the sound power level, but several source type specific parameters. For example, the following sources are parametric sources: • • • • • road (see chapter 2.4) railway (see chapter 2.6) parking lot (see chapter 2.7) crossing with traffic lights (see chapter 2.5) tennis point of service (see chapter 2.3) Those source types require to specify an emission parameter which is specific to the standard/guideline or, for example the overall traffic count, the percentage of heavy vehicles, the type of road surface, and the traffic speed where the emission parameter is calculated from. The input figures can be specified for the three time periods Day/Evening/ Night even when the selected standard just provides only one or two time periods. CadnaA - Reference Manual Parametric Sources 2 2 Chapter 2 - Sound Sources The input of objects is explained in the manual „Introduction to CadnaA“. 2 CadnaA - Reference Manual 23 Chapter 2 - Sound Sources 2.1 Industrial Sources 2.1 Industrial Sources The general source types, such as point, line and area sources (horizontal and vertical), are used to model a variety of noise sources including also the building radiation. Moreover, they may have an individual directivity (see chapter 2.2). 2 When applying these sources to mode the sound radiation from buildings the object snap is activated in order to place them in front of the building’s facade at a distinct distance (see chapter 9.3). This prevents from the source being placed inside the building. see chapter 2.1.1 "Common Input Data" for detailed information on the common parameters of the general sound sources. A point source is entered at the position of the mouse pointer with a mouse click at the desired location. The point source is represented by a cross. Point Source Point sources are noise sources whose dimensions are small in comparison to the distance to the receiver points. Examples are ventilation openings, pumps, motors, and people shouting. Line sources are modelled as open polygons. Line sources have one dimension only, while the dimensions in the other two orthogonal dimensions are small compared with the distance to the receiver points. Examples are pipelines, conveyor belts, and traffic routes on a factory site. Line Source Upon calculation, CadnaA subdivides the line source in a two-step procedure. First, the line source is subdivided into sections being screened and sections not being screened by any obstacles lying between the receiver and the sub-source (see chapter 6.1.3 "Projection at extended Sound Sources"). In a second step, the distance between the receiver and each section is determined and a further subdivision is required if the section length exceeds the minimum distance criterion. Area sources are modelled as closed polygons. They are noise sources extending in two dimensions while the third dimension perpendicular to its area is small in relation to the receiver distance. CadnaA - Reference Manual Area Source 4 2 Chapter 2 - Sound Sources 2.1 Industrial Sources CadnaA subdivides upon calculation the area sources into sufficiently small sub-areas. In the centre of each sub-source a point source with the appropriate partial sound power is placed. This procedure results in a fine grid of point sources, the total emission of which represents the area source. 2 horizontal Area Source Horizontal area sources are inserted by entering their horizontal projection. Examples of area sources are parking lots (see chapter 2.7), sports facilities, and even entire industrial or commercial areas. vertical Area Source Vertical area sources are inserted by entering their horizontal projection as an open polygon line. CadnaA - Reference Manual Chapter 2 - Sound Sources 2.1 Industrial Sources Upon calculation, CadnaA subdivides the area source in a two-step procedure. First, the area source is subdivided into partial areas being screened and partial areas not being screened by any obstacle lying between the receiver and the source (see chapter 6.1.3 "Projection at extended Sound Sources"). Then, in the second step, the distance between the receiver point and each partial area is determined and a further subdivision is required if the largest dimension of a partial area exceeds the minimum distance criterion. Geometric definition of the vertical area source In order to enter a window (as illustrated above) as a sound-radiating area, enter a vertical area source as a polygon line in xy-plane at a short distance in front of the facade. For a clear distinction, a distance of approximately 0.05 m is used. This distance is automatically set via the dialog Object Snap (Options menu) prior to the input of the vertical area source (see chapter 9.3 "Object Snap"). CadnaA - Reference Manual 25 2 6 2 Chapter 2 - Sound Sources 2.1 Industrial Sources 2 Building Vertical area source Vertical area source in front of a facade On the edit dialog of the vertical area source specify the position of the top edge via button Geometry. As with any other object, this height may be defined as relative or absolute value, or with respect to the roof of a building. The latter is particularly convenient when entering e.g. ventilators placed onto a roof. The lower edge of the vertical area is specified as „z-dimension“ downwards from the top edge. More complicated outlines of vertical soundradiating areas can be approximated by several rectangular areas. Upon calculation, the vertical area source is replaced by a series of line sources with a spacing of 1 m. These are subdivided into sections as described above. The subsequent chapters are specific for each standard or guideline available in CadnaA. These specifications do not represent a copy of the standardized procedures, rather the way they are implemented. CadnaA - Reference Manual 27 Chapter 2 - Sound Sources 2.1.1 Common Input Data 2.1.1 Common Input Data On the dialogs Point Source, Line Source, Area Source and vertical Area Source the following values and settings govern the resulting sound power level: • • • • • • • • 2 Type (Single Band, Spectrum or SET-S module) Frequency (Hz) Correction (dB) type of emission: PWL: at point, line, area sources and PWL’: at line sources PWL’’: at area sources PWL-Pt: at line and area sources TransLoss (dB) Attenuation (dB) Area (m²) normalized A (dBA) as well as the input or settings for operating time („Source in Steady-State“, „Operating Time (min)“). The resulting sound power level is calculated from these parameters and displayed for the time periods Day/Evening/Night (Result. PWL“). From the list box „Type“ the following options can be selected: • • • Type Single band, Spectrum or a pre-defined SET-S module (see chapter 12.2). The options „Single band“ and „Spectrum“ require the input of acoustical data determining the resulting sound power level. In contrary, the selection of an SET-S module prompts to specify the physical parameters of the respective type of source in a sub-table (e.g. flow rate in m³/s, nominal capacity in kW). From these parameters the sound power level spectrum is calculated. By using the attribute FREQ the dominant frequency can be changed. Use the space key or a blank to toggle to type „Spectrum“. CadnaA - Reference Manual Toggling the Type per Attribute 8 2 Chapter 2 - Sound Sources 2.1.1 Common Input Data Single band / Frequency (Hz) With selection „Single band“ the sound power level entered under PWL, PWL’, PWL’’, or PWL-Pt is considered as the A-weighted total level. In this case, for frequency dependent propagation parameters (e.g. air absorption) the resulting values is calculated for the frequency specified. Default frequency value is 500 Hz (see ISO 9613-2, section 1 /8/). Spectrum With selection „Spectrum“ the sound power level entered under PWL, PWL’, PWL’’, or PWL-Pt is considered as A-weighted level per octave band. In this case, the displayed sound power level PWL („Result. PWL“ in dB(A)) results from adding 10 lg 9 = 9,5 dB for 9 octaves. 2 Alternatively - and this is the common procedure in conjunction with using spectra - instead of a figure an ID-code of the respective spectrum is entered or selected. Example for „Spectrum“ • Enter the local library (see Chapter 12 - Libraries) via Tables| Libraries (local)|Sound Levels the following sound power spectra: • On the point source’s dialog select for „Type“ the option „Spectrum“ for spectral calculation. • Enter the ID-code „SP_001“ of compressor 1 into the box PWL. This refers to that spectrum. • The text sequence SP_001 may either be entered via the keyboard or be selected from the local library by clicking the file selector symbol, subsequently selecting the first data set and clicking OK. Access to the global libraries occurs by clicking the file selector symbol while holding the SHIFT-key depressed. Upon selection of a spectrum from the global library the data set is copied automatically to the local library. CadnaA - Reference Manual Chapter 2 - Sound Sources 2.1.1 Common Input Data In this example, after having selected the compressor spectrum the resulting A-weighted sound power level (Result. PWL) and the spectrum shape are displayed, the latter in the lower right corner of the dialog Point Source. Dialog Point Source with referencing to spectrum-ID SP_001 • Now, upon clicking again to the file selector symbol and selecting a different spectrum, the former reference will be replaced by the new one. In case a second spectrum should be added energetically to the first one, considering the rules of level summation, press the CTRL-key prior to selection of the second spectrum. This causes the second spectrum to be entered with the operator ++ in front being the symbol for energetic level summation (for further operators see the CadnaA-manual „Attributes, Variables, and Keywords“, chapter "Chapter 5 - Operators & Functions"). This summation formula can also be entered via the keyboard. During typing the red text indicates that the formula is not complete or cannot be evaluated, respectively. Formulas in the input box „PWL“ are restricted to 15 characters. CadnaA - Reference Manual 29 2 10 2 local SET-S modules 2 Chapter 2 - Sound Sources 2.1.1 Common Input Data The SET-S modules from the local SET-S library are listed here. Upon selection of a module and input of the respective parameters a..j on the sub-table the resulting spectrum and the A-weighted total level „Result. PWL“ is displayed. Example: SET-S module „Radial Roof Ventilator“ selected Sound power of roof ventilator after specifying its parameters A total overview of all SET-S modules delivered with CadnaA see chapter 12.2 "SET-S". Attributes Via the attributes SET_ID and SET_PARM_A to _J an SET-S module can be selected and its parameters be defined (see chapter 1.1 in the CadnaA manual „Attributes, Variables, and Keywords“. CadnaA - Reference Manual 2 11 Chapter 2 - Sound Sources 2.1.1 Common Input Data The spectrum monitor at the bottom right corner of the source dialog displays the frequency spectrum in from of bars. Clicking the diagram cycles among no weighting (i.e. linear) and A-, B-, C- or D-weighting. With this switching the emission of the source remains. Spectrum Monitor Depending on the source type the emission can be specific for the following „types“ of sound power levels (attribute „LWTYP“): PWL-Type • with point sources: by the sound power level PWL in dB(A), Dialog Point Source • with line sources: by the sound power level PWL in dB(A), by the sound power level per unit length PWL’ in dB(A), or by the sound power level PWL-Pt of a moving point source (default setting: PWL'), Dialog Line Source with list box „LWTYP“ opened CadnaA - Reference Manual 2 12 2 Chapter 2 - Sound Sources 2.1.1 Common Input Data • 2 with area sources: by the sound power level PWL in dB(A), by the sound power level per unit area PWL’’ in dB(A), or by the sound power level PWL-Pt of a moving point source (default setting: PWL’’). Dialog Area Source (horizontal) with list box „LWTYP“ opened The input box to the right of the list box for the emission type (attribute LWTYP) may contain a single number, a reference to a spectrum, or a combination of both, or even an equation. Result. PWL When the sound power level per unit length PWL, is entered for a line source or the sound power level per unit area PWL’’ is entered for an area source, the total sound power level resulting from the dimensions of that source is displayed here (excluding the correction for operating time and the directivity index K0/D). This sound power level is used as the emission characteristic of the source within the calculation of sound propagation. As the height of the terrain at the polygon points of the source is not known when the values are entered, this total sound power level refers, with relative heights, to the horizontal projection of the source. Consequently, this will not be correct for inclined line or area sources. Upon calculation, however, the absolute heights at the polygon points is updated and the correct total sound power level is determined. CadnaA - Reference Manual 2 13 Chapter 2 - Sound Sources 2.1.1 Common Input Data When entering the sound power level per unit length or unit area for inclined line or area sources, the heights of which are given as relative coordinates, the total value displayed for „Result PWL“ is not yet correct as the increased radiating area due to the inclination of the source is not considered so far. However, this will the case when the dialog is closed and reopened. Inclined Sources 2 Example: inclined area source Plane area source and inclined area source (by 45 degrees), both having the same 2D-ground plane Resulting sound power level of a plane area source (left) and of a by 45° inclined area source (right), both having the same 2D-ground plane CadnaA - Reference Manual 14 2 Chapter 2 - Sound Sources 2.1.1 Common Input Data Correction To consider different emissions for the time periods Day, Evening, and Night specify a correction for each of these periods. The correction entered will be added to the sound power level. Attenuation Via the „Attenuation“ box a value can be entered which will be considered as an additional damping of the source’s emission. Furthermore, attenuation spectra from the local and global libraries can be referenced. The entered or referenced attenuation will be subtracted from the sound power level. Example After the compressor (with PWL=104 dB(A)) of the recent example a silencer with an additional attenuation of 8 dB is installed. 2 Dialog Point Source with an attenuation of 8 dB • Using Equations Enter in box „Attenuation“ the figure 8, resulting in a sound power level („Result. PWL“) of 96 dB(A). The attenuation input box may also receive complex formulas or the ID of a spectrum. Formulas for „Attenuation“ are restricted to 63 characters. While the „Attenuation“ value is directly subtracted from the PWL, the resulting PWL when specifying „TransLoss“ - in conjunction with the interior sound pressure level („interior level“) - considers also an area and a diffuse-to-free-field correction (see below). CadnaA - Reference Manual Chapter 2 - Sound Sources 2.1.1 Common Input Data 2 15 For example, several attenuations may attenuate the sound power radiated (e.g. pipe elbows, changes in cross section, fittings, and silencers). This sum of attenuations may be described by, e.g.: 8+4+3.5+2. 2 Of course, the total attenuation could be entered by a single figure directly, but the specification as a sum illustrates more obviously the individual attenuations contributing and also will be listed in the respective column of the source table. The line offers to enter even more complex formulas, such as: ((8+4+3.5+2)++23)-19. As described for other input boxes, ++ stands for the energy-equivalent (or level) addition, and -- for the level subtraction (see also CadnaA-manual „Attributes, Variables, and Keywords“, see chapter "Chapter 5 - Operators & Functions"). Furthermore, arbitrary damping spectra from the local or global library (see Chapter 12 - Libraries) can be referenced via the input box „Attenuation“. In the subsequent figure, the attenuation spectra of two changes in cross section and a silencer are combined at a line source modeling a pipe section: Combined attenuations on dialog Line Source CadnaA - Reference Manual Referencing Attenuations 16 2 2 Sound Power of a moving Point Source PWL-Pt Chapter 2 - Sound Sources 2.1.1 Common Input Data The line or the horizontal area source may be used to model the emission of a moving point source (emission type option: PWL-Pt). When using a line source, the sound power level of the point source, the number of events per hour Q (number of pass-bys) and the speed (in km/h) have to be specified. The resulting sound power level PWL and the sound power level per unit length PWL’ calculate from: PWL PWLPt 10 lg Q l v 10 lg 10 lg 30 dB (h 1 ) ( m) (km / h) PWL ' PWLPt 10 lg Q v 10 lg 30 dB 1 (h ) (km / h) With area sources, the sound power level of the point source and the number of events Q are required. The resulting sound power level PWL and the sound power level per unit area PWL’’ calculate from: PWL PWLPt 10 lg Q (h 1 ) PWL ' ' PWLPt 10 lg Q S 10 lg 2 1 (h ) (m ) Example see manual „Introduction to CadnaA“, chapter 6.2 "Internal Driveways and Areas" normalized A With this check box „normal. A“ activated and a number entered, a constant K in dB is subtracted from or added to the frequency-band levels resulting from the specified PWL in order to obtain this value for the total A-weighted sound power level. This option enables the application of normalized spectra (with a total sum level of 0 dB) the final emission value of which is specified be entering the respective value in input box „norm. A“. CadnaA - Reference Manual 2 17 Chapter 2 - Sound Sources 2.1.1 Common Input Data All types of general sources described above can be applied to model the sound radiation from buildings. In order to specify the radiated sound power based on the (diffuse) interior level SPL activate the option „TransLoss“. Subsequently, the emission type (Lw-type) switches to „Interior Level“. Enter an interior level and in the box „TransLoss“ a single number rating (weighted sound reduction index Rw or STC) or the ID-code of a sound reduction index spectrum. All techniques for the selection of spectra from the libraries and the handling of user-defined formulas apply as before. Formulas in the input box „TransLoss“ are restricted to 15 characters. Dialog vertical Area Source (radiating area S=100 m²), Transmission Loss specified by a single number rating The resulting sound power level PWL calculates in CadnaA from (S0=1 m²): • for spectral sources (S0=1 m2): LwA LpA R f 6 dB 10 lg • S S0 for sources based on the A-weighted sound power level (S0=1 m²): LwA LpA Rw 4 dB 10 lg CadnaA - Reference Manual S S0 Transmission Loss 2 18 2 2 Chapter 2 - Sound Sources 2.1.1 Common Input Data The calculation for single number ratings follows the VDI guideline 2571 (edition 8.1976 /37/) assuming RA = Rw + C = Rw - 2 dB (with the spectrum adaptation term C according to ISO 717-1 /10/). In general, a spectrum adaptation term C=-2 dB is obtained for heavy monolithic walls and floors only. For lightweight building structures the spectrum adaptation term C can be lower, e.g. down to C=-6 dB. The informative annex B of the European Standard EN 12354-4 lists the diffusity correction Cd depending on the type of room: Type of Room Cd (dB) relatively small, uniformly shaped rooms (diffuse field), reflecting walls (REMARK: as applied by VDI) -6 relatively small, uniformly shaped rooms (diffuse field), absorbing walls -3 large flat or long halls, many sources (average industrial building), reflecting walls -5 industrial building, few dominating directional sources, reflecting walls -3 industrial building, few dominating directional sources, absorbing walls 0 When the option „TransLoss“ is activated and the transmission loss is zero a value of zero has to be entered. With this box being empty no radiated sound power results. Additionally, with point and area sources an area (m²) has to be entered in the respective box as this value is not available from the object’s geometry data (see the subsequent section). CadnaA - Reference Manual Chapter 2 - Sound Sources 2.1.1 Common Input Data • Select for the sound insulation of the facade in the previous example the spectrum „steel sheet with trapezoidal corrugations 45 mm“ from the global library (menu Tables|Libraries (global)|Sound Reduction (ID: R26). • To this end, click on dialog vertical Area Source with the SHIFT-key depressed on the file selector symbol to the right of the input box „TransLoss“. • Select the spectrum with ID „R26“ and click OK. • Switch the emission type from „Single band“ to „Spectrum“. The sound power level and its spectrum as resulting from the input data is displayed. Dialog vertical Area Source (radiating area S=100 m²), Transmission Loss specified by referencing a sound reduction spectrum CadnaA - Reference Manual 2 19 Example for spectral Sound Reduction Index 2 20 2 Area (m²) 2 Chapter 2 - Sound Sources 2.1.1 Common Input Data With point and line sources a radiating area has to specified when modelling sound radiation based on the indoor level. To this end, click the check box, and enter the relevant area. With horizontal or vertical area sources are respective value is required just when the actual radiating area differs from the geometrical area of the area source. Example For horizontal and vertical area sources, the difference between the sound power level PWL and the sound power level per unit area PWL’’ is still determined - as before - from the entered geometry, since the entire source radiates as drawn. The sound radiation from a glazed facade within a heavy outer wall is modelled by a vertical area source in front of the entire wall. In order to ignore the radiation from the heavy parts of the facade just the area of the actual glass facade is entered. When the option „Area (m²)“ is not activated, CadnaA considers the entire area source as derived from the object’s geometry in the calculation. Check for the value of „Result. PWL“. As long as it is zero, parameters are still missing, for instance, with calculations based on the indoor level either the area or the sound reduction index/TL. The length (m) of the line source and the area of the area source (m²) can be checked via the dialog Geometry. For a vertical area source - drawn from two polygon points - this value is zero as this area entered refers to the horizontal projection (2D-area). Instead, the area of vertical area sources can be seen after a calculation in the box „Area (m²)“ on the edit dialog. The length of a line-like object can be specified in an exact way (see manual „Introduction to CadnaA“, context menu command „Specify Length“). and chapter 3.1.6 "Generate Building" in this manual. CadnaA - Reference Manual 2 21 Chapter 2 - Sound Sources 2.1.1 Common Input Data By default, the option „Source in Steady-State“ is selected where no correction for operating time applies. In this case, the specified noise emission is constant for each entire daily period (see chapter 6.2.4). Source in SteadyState / Operating Time (min) By selecting the option „Operating Time (min)“, the source-specific operating time in minutes can be entered for each daily period „Day|Recreation (=Evening)|Night“. The correction for operating time result from the operating times and the reference time intervals D|E|N specified in the configuration of calculation (see chapter 6.2.4) and calculates from: 10lg Toperating time Treference time dB Furthermore, diurnal patterns (= hourly emission profile covering 24 hours) can be used for industrial sources in CadnaA. To this end, first define a diurnal pattern in the local or global library „Diurnal Patterns“ (see chapter 12.3). Subsequently, this diurnal pattern can be selected from the list box. Point source with selected diurnal pattern TG_01 Diurnal patterns may also get assigned using the attribute TEINW_GANG (see chapter 1.1 in the manual „Attributes, Variables, and Keywords“). CadnaA - Reference Manual Addressing Diurnal Patterns 2 22 2 Chapter 2 - Sound Sources 2.1.1 Common Input Data 2 Example 1 When using diurnal patterns describing the additional evaluation parameter „loudest hourly level per time period D/E/N“ (L1hMaxD, L1hMaxE, L1hMaxN) are available on tab „Evaluation Parameter“ (see chapter 6.2.5). The receiver level of a point source without correction for operating time is 35 dB(A). Then, the following diurnal pattern TG_01 is selected: Diurnal pattern TG_01 for example 1 Considering the following allocation of hours to the time periods: • • • Day (D): 6-18 h (= 12 hours) Evening (E): 18-22 h (= 4 hours) Night (N): 22-6 h (= 8 hours) CadnaA - Reference Manual 2 23 Chapter 2 - Sound Sources 2.1.1 Common Input Data PS with diurnal causes the following results as listed in the subsequent table: pattern 1 - A & B.cna Evaluation Parameter Calculation Remarks Ld = 35 dBA source active permanently during D A Le Ln L1hMaxD L1hMaxE L1hMaxN 35 10lg 4 30 min 35 3 32.0 dBA 4 60 min source for (4*30) min active during E B 35 10lg 15min 35 15.1 19.9 dBA 8 60 min source just 15 min active during N A because emission is constant during D A = 35 dBA 35 10lg 30 min 35 3 32.0 dBA 60 min source is active for 30 min during loudest hour B 35 10 lg 15min 35 6 29.0 dBA 60min source is active for 15 min during loudest hour A Again, the point source causing a receiver level of 35 dB(A) without correction for operating time is used. Then, the diurnal pattern TG_02 as shown on the following page is selected. Considering the following reference times for the daily periods: • • • File Day (D): 7-20 h (= 13 hours) Evening (E): 6-7 h and 20-22 h (= 3 hours) Night (N): 22-6 h (= 8 hours) CadnaA - Reference Manual Example 2 2 24 2 Chapter 2 - Sound Sources 2.1.1 Common Input Data PS with diurnal causes the following results as listed in the subsequent table: pattern 2.cna 2 Eval.Param. Calculation Remarks Lde Ld = 35 dBA Ld: source is permanently active during D, Le: source is just active for (3*10) min during E, Lde: considers a penalty of 6 dB for recreation/ evening period Le 3 10 min 35 10lg 35 7.8 27.2 dBA 3 60 min 1 0.1 L 6 L de 10 lg 13*10 0.1L d 3*10 e 34.7 dBA 16 Ln L1hMaxN 35 10lg 4 30 4 15 min 8 60 min 35 10lg 30 min 35 3 32.0 dBA 60 min 35 4.3 30.7 dBA source active for 180 min within 480 min loudest hour occurring during N (last from 22-2 hours) Diurnal pattern TG_02 for example 2 CadnaA - Reference Manual 2 25 Chapter 2 - Sound Sources 2.1.1 Common Input Data solid angle correction K0 (dB) accord. to VDI 2714 /38/ or the directivity index D accord. to ISO 9613 /8/ The excess level in the direction of sound radiation due to reflecting surfaces close to the source can be accounted for by a global correction, the solid angle correction K0 or the directivity index D. Since the ground reflection is already accounted for within the calculation according to ISO 9613-2, just the remaining reflecting surfaces are to be considered when determining the value of K0 (thus called „K0 without Ground“, i.e. ignoring the ground). The concept of the directivity index refers to omni-directional radiating point sources. In case of directional sound radiation (i.e. using a directivity pattern, see chapter 2.2) it is recommended to set the directivity index D to 0 dB, since otherwise the radiation - irrespective of the shape of the directivity pattern - would be generally increased by the entered directivity index. In case of K0 or D > 0 the reflection from the building itself (i.e. reflector near the source) must not be included as the excess level is already accounted for by the correction K0 resp. D. In order to maintain the building’s reflective properties for all other sound sources the „Minimum Distance from Source to Reflecting Object“ specified via menu Calculation| Configuration, tab „Reflection“ (see chapter 6.2.8), has to be larger than the distance of the source in front of the facade (e.g. 0.5 m). see chapter 4.2.3, section "Additional Information for object „Building“" Starting with CadnaA release version 3.6 the horizontal distance (2D distance) is used to calculate the directivity index K0 or D - instead of the 3D distance between source and receiver. This change causes level differences for very different heights of source/receiver only. CadnaA - Reference Manual K0 without Ground 2 26 2 Chapter 2 - Sound Sources 2.1.1 Common Input Data Examples for K0 / D 2 Source Location K0 / D without Ground (dB) Source at any height above the ground (solid angle: 2) 0 Source at any height above the ground in front of a wall (solid angle: ) 3 Source at any height above the ground in a corner (solid angle: /2) 6 CadnaA - Reference Manual Chapter 2 - Sound Sources 2.1.2 ISO 9613 2.1.2 ISO 9613 Beyond the source characteristics as specified in chapter 2.1.1 "Common Input Data" no further parameters are to be considered with the application of this standard. 2 27 The national editions of ISO 9613 may state further application notes (e.g.: /8/ /56/). CadnaA - Reference Manual 2 28 2 Chapter 2 - Sound Sources 2.1.2 ISO 9613 2 CadnaA - Reference Manual Chapter 2 - Sound Sources 2.1.3 Nordic Prediction Method 1996 2.1.3 2 29 Nordic Prediction Method 1996 Beyond the source characteristics as specified in chapter 2.1.1 "Common Input Data" no further parameters are to be considered with the application of this standard. CadnaA - Reference Manual 2 30 2 Chapter 2 - Sound Sources 2.1.3 Nordic Prediction Method 1996 2 CadnaA - Reference Manual Chapter 2 - Sound Sources 2.1.4 Nord 2000 2.1.4 2 31 Nord 2000 Beyond the source characteristics as specified in chapter 2.1.1 "Common Input Data" no further parameters are to be considered with the application of this calculation procedure. CadnaA - Reference Manual 2 32 2 Chapter 2 - Sound Sources 2.1.4 Nord 2000 2 CadnaA - Reference Manual Chapter 2 - Sound Sources 2.1.5 Ljud från vindkraftverk 2.1.5 2 33 Ljud från vindkraftverk Beyond the source characteristics as specified in chapter 2.1.1 "Common Input Data" no further parameters are to be considered with the application of this standard. CadnaA - Reference Manual 2 34 2 Chapter 2 - Sound Sources 2.1.5 Ljud från vindkraftverk 2 CadnaA - Reference Manual Chapter 2 - Sound Sources 2.1.6 BS 5228 2.1.6 2 35 BS 5228 Beyond the source characteristics as specified in chapter 2.1.1 "Common Input Data" no further parameters are to be considered with the application of this standard. CadnaA - Reference Manual 2 36 2 Chapter 2 - Sound Sources 2.1.6 BS 5228 2 CadnaA - Reference Manual Chapter 2 - Sound Sources 2.1.7 Harmonoise 2.1.7 2 37 Harmonoise Beyond the source characteristics as specified in chapter 2.1.1 "Common Input Data" no further parameters are to be considered with the application of this standard. CadnaA - Reference Manual 2 38 2 Chapter 2 - Sound Sources 2.1.7 Harmonoise 2 CadnaA - Reference Manual Chapter 2 - Sound Sources 2.1.8 Concawe 2.1.8 2 39 Concawe Beyond the source characteristics as specified in chapter 2.1.1 "Common Input Data" no further parameters are to be considered with the application of this standard. CadnaA - Reference Manual 2 40 2 Chapter 2 - Sound Sources 2.1.8 Concawe 2 CadnaA - Reference Manual Chapter 2 - Sound Sources 2.1.9 NMPB-Industry 2008 2.1.9 2 41 NMPB-Industry 2008 Beyond the source characteristics as specified in chapter 2.1.1 "Common Input Data" no further parameters are to be considered with the application of this standard. CadnaA - Reference Manual 2 42 2 Chapter 2 - Sound Sources 2.1.9 NMPB-Industry 2008 2 CadnaA - Reference Manual Chapter 2 - Sound Sources 2.1.10 CNOSSOS-EU (Industry) 2.1.10 2 43 CNOSSOS-EU (Industry) Beyond the source characteristics as specified in chapter 2.1.1 "Common Input Data" no further parameters are to be considered with the application of this procedure. CadnaA - Reference Manual 2 44 2 Chapter 2 - Sound Sources 2.1.10 CNOSSOS-EU (Industry) 2 CadnaA - Reference Manual 2 45 Chapter 2 - Sound Sources 2.1.11 Schall03 (2014) 2.1.11 Schall03 (2014) Beyond the source characteristics as specified in chapter 2.1.1 "Common Input Data" no further parameters are to be considered with the application of this procedure. 2 In Schall03 (2014), supplement 3 /26/, the acoustical characteristics of noise sources at marshaling yards are listed. These emission datasets are available in CadnaA (see menu Tables/Libraries (global)/Sound Levels, see also Chapter 12 - Libraries). Characteristics of marshaling yards In case these emission datasets according to Schall03 (2014) are not displayed, proceed as follows: Loading Emission Datasets • Open the Library-Manager on the Tables menu. • Select the library „Sound Levels“ and the type „Default“. • Select the action „Copy to“ (default) with the destination „Local“ or „Global“. • After clicking OK, the spectra are written to the selected library. Sound power spectra according to Schall03 (2014), supplement 3, for noise sources at marshaling yards („name“ of sound just available in German for the time being) CadnaA - Reference Manual 46 2 Chapter 2 - Sound Sources 2.1.11 Schall03 (2014) 2 CadnaA - Reference Manual Chapter 2 - Sound Sources 2.1.12 HJ 2.4 (2009) 2.1.12 2 47 HJ 2.4 (2009) Beyond the source characteristics as specified in chapter 2.1.1 "Common Input Data" no further parameters are to be considered with the application of this procedure. CadnaA - Reference Manual 2 48 2 Chapter 2 - Sound Sources 2.1.12 HJ 2.4 (2009) 2 CadnaA - Reference Manual Chapter 2 - Sound Sources 2.1.13 Further Procedures for Industrial Noise 2.1.13 2 49 Further Procedures for Industrial Noise Information on the following standards or guidelines for industry can be found in the German version of the CadnaA reference manual: • VDI 2714/2720, Germany • OEAL 28 (1987), Austria • DIN 18005 (1987), Germany CadnaA - Reference Manual 2 50 2 Chapter 2 - Sound Sources 2.1.13 Further Procedures for Industrial Noise 2 CadnaA - Reference Manual 2 51 Chapter 2 - Sound Sources 2.2 Directivity at Industrial Sources 2.2 Directivity at Industrial Sources When sound sources are not radiate uniformly in all directions, this can be accounted for by selecting a pre-defined directivity or by entering a userdefined directivity. The calculation procedure selected for industrial noise (see chapter 6.2.1) specifies on how to consider directivity within the calculation of sound propagation. However, the majority of the calculation procedure for industrial noise do not specify much detail on input and application of directivity data. The following statements refer, as an example, to the application of directivities in conjunction with ISO 9613-2. The equation (3) in ISO 9613-2 /8/ introduces the directivity correction Dc: LfT DW L W D C A where LfT(DW) LW energy-equivalent continuous sound pressure level for downwind in octave band width, in dB sound power level in octave band width of the point source, in dB DC (reference sound power (10-12 W) directivity correction in dB, consisting of: DC DI D DI directivity index of the point source D correction for sound radiation into solid angles smaller than 4 steradians total attenuation per octave band occurring on the propagation path, in dB A According to the equation for LFT(DW), the directivity correction is added to the sound power level. This requires that the directivity itself must be normalized to a sum level of zero dB, in order not to alter the sound power radiated by the point source. More details for input or application of directional effects (for example, angular step-size, limitations with regard to the ray tracing algorithm applied etc.) cannot be found in ISO 9613-2. This statement also applies for other standards and procedures for industrial noise. CadnaA - Reference Manual 2 Directivity & ISO 9613-2 52 2 Chapter 2 - Sound Sources 2.2 Directivity at Industrial Sources 2 Button „Directivity“ When modeling road, railway or aircraft noise directional effects may also be considered on the source-side within the calculation of sound propagation. In these cases, however, the directivities applied form an integral part of the source description and can, therefore, not be modified by the user. In CadnaA, stands over the source dialog of industry sources (point, line, area sources) the "directivity" are available which opens the dialog directivity. Dialog Directivity CadnaA - Reference Manual 2 53 Chapter 2 - Sound Sources 2.2 Directivity at Industrial Sources Dialog Options In order to account for non-uniformal sound radiation of industrial sources (point, line, area sources) two types of directivities are available in CadnaA: • List box „Directivity“ 2 predefined directivities: Select from the list box „Directivity“ a predefined directivity. Presently, the following directivities are available: chimney (VDI 3733, see chapter 2.2.1) element & opening (ÖAL 28, see chapter 2.2.2) • The directivities of elements and openings according to ÖAL 28 are independent of frequency. user-defined directivities: Individual, frequency-dependent directivities can be defined via the menu Tables|Libraries (local)|Directivity (see chapter 2.2.3). When user-defined directivities have been entered, their name will appear at the end of the list box „Directivity“ on the Directivity dialog. With this option (default setting), the normal direction (0 °) of the selected directivity for point sources will point into the normal direction of a nearby building facade. After calculation, the coordinates of the directivity vector are shown into the corresponding input boxes „xyz“. CadnaA - Reference Manual Directivity, Automatic Direction 54 2 Automatic orientation depending on source type 2 Chapter 2 - Sound Sources 2.2 Directivity at Industrial Sources The orientation of the directivity vector depends on the type of industrial source. The following strategies are applied: source type orientation of the directivity vector point source The directivity vector is pointing into the normal direction of the nearest reflecting building facade, within a 1 m radius of the point source. When no reflecting facades are found, the directivity vector is pointing into +z direction (independent of the source height). line source picture vertical cross section The directivity assigned points into positive z direction (z=1), since the ground is seen as a reflection surface. The directivity vector is pointing from the first to the last polygon point (for each segment of the line source). The resulting level distribution results from assigning the directivity selected to each segment of the line source. top view area source The directivity vector is pointing into the normal direction of the area source. The resulting distribution results from assigning the directivity to each point-like sub-source within the borders of the area source. vertical cross section CadnaA - Reference Manual 2 55 Chapter 2 - Sound Sources 2.2 Directivity at Industrial Sources vertical area source The directivity of vector is pointing to the right, seen from the first to the last point. Consequently, enter vertical area sources at buildings counterclockwise! 2 top view The automatic orientation of directivity vector for point sources only occurs nearby, reflecting worldwide, not with reflective screens or cylinders. When activating this option the directivity vector can be individually oriented by entering the coordinate direction xyz. The figures entered will be Directivity Vector normalized after calculation to the unit circle (radius R=1, x2 + y2 + z2=1). Examples: Vector Coordinates Directivity vector is pointing towards the direction ... (x, y, z) = (1, 0, 0) ... of the positive x-axis (i.e. to the "right"). (x, y, z) = (0, 0, 1) ... of the positive z-axis (i.e. "upwards").. (x, y, z) = (1, 1, 0) ... the bisecting line between the positive x and the positive y axis (at 45 degrees, to the „right upper corner“). After a calculation the vector coordinates are normalized to the unit circle, in this case (x, y, z) = (0.7071, 0.7071, 0) [R=sqrt(0.7071^2+0.7071^2)]. see chapter 6.3 "Directivity" in the manual „Introduction to CadnaA“ CadnaA - Reference Manual Examples 56 2 2 Chapter 2 - Sound Sources 2.2 Directivity at Industrial Sources Exhaust Velocity (m/s) is required to calculate the chimney's directivity according to VDI-guideline 3733. Exhaust Gas Temperature (°C) as above Wind Speed (m/s) as above Further information Interpolation when applying directivity Directivity at reflected rays When evaluating of user-defined directivities (via menu Tables|Libraries (local)|Directivity) to ray paths the following step apply: • For each ray (source-receiver) or (source-first reflector, see below) the angle to North direction is determined. • Depending on the directivity vector and the ray‘s direction the relevant directivity correction is determined for each ray. For ray directions between two angular steps of 15° (see chapter 2.2.3) the directivity correction results from linear interpolation. • The directivity index DI is added to the correction for solid angle D - if any - and considered as DC in the calculation of propagation (see chapter 6.5 "Calculation Protocol"). The calculation procedures - e.g. also not ISO 9613-2 - do not specify how to handle the directivity correction in conjunction with the reflected rays. In CadnaA, the following strategy is used: • In case of reflected rays - independent of the reflection order - the first section of the ray (from the source to the 1st reflector) determines the direction being used to evaluate the relevant directivity correction. • This directivity correction is used, even if the ray, possibly after multiple reflections, arrives at the receiver from a different direction. CadnaA - Reference Manual 2 57 Chapter 2 - Sound Sources 2.2.1 Sound Radiation from Chimneys or Stacks 2.2.1 Sound Radiation from Chimneys or Stacks The directional sound radiation of chimney outlets can be estimated by applying a method developed in a research project funded by th German Environmental Protection Agency (UBA) from 1981 /45/. Radiation Characteristics of Chimneys The simplified approach to determine the radiation characteristics of chimneys and cooling towers is valid with the following conditions: Range of Application • diameter of the chimney opening d = 5 to 7 m • • • wind speed WL 3 ms-1 emitted medium: CO2, temperature range TF = 473 to 773 K emitted medium: steam, temperature TF = 308 K The following figure shows the geometrical situation: Directivity Correction Radiation by chimneys and stacks The angle calculates from: –1 2 2 –4 –1 = 90 + arc tan h s – arc sin h + s 10 – arc tan W L T F W F T L CadnaA - Reference Manual 2 58 2 Chapter 2 - Sound Sources 2.2.1 Sound Radiation from Chimneys or Stacks Directivity Index K (in dB): 2 f in Hz 63 125 250 500 1000 2000 4000 8000 30° 2,0 2,5 2,5 3,6 3,0 2,0 2,0 2,0 45°-60° 4,0 4,8 3,2 4,1 4,8 4,8 4,8 4,8 75° 1,0 1,5 1,5 1,5 0,8 0,5 0,5 0,5 90° -2,0 -2,5 -3,0 -3,5 -4,8 -5,6 -5,6 -5,6 105° -4,0 -5,5 -7,0 -9,0 -10,0 -10,6 -10,0 -10,0 120° -5,0 -7,5 -9,2 -11,5 -15,2 -19,8 -20,0 -20,0 The following parameters are used (see the preceding figure): Example • • h s source height (relative to the receiver) [m] distance receiver-source (z coordinate) [m] • • WL TF downwind velocity [ms-2] temperature of the exhaust gas/medium [K] • • WF TL velocity of the exhaust gas/medium [ms-2] ambient temperature [K] see chapter 6.4 "Radiation from Stacks and Chimneys" in the manual „Introduction to CadnaA“ see also: chapter 6.2.9.1 "ISO 9613". section "Sources in Building/Cylinder do not shield" (or any other chapter in chapter 6.2.9 "Industry Tab") CadnaA - Reference Manual Chapter 2 - Sound Sources 2.2.2 Sound Radiation from Elements & Openings 2.2.2 2 59 Sound Radiation from Elements & Openings The Austrian guideline OEAL 28 „Sound radiation and sound propagation“ (title translated from German, edition Dec. 1987 /54/) specifies frequency independent directivities for the radiation by building elements and by openings. within the building‘s facade The directivity for the radiation by building elements has been modified with the amendment of 2001 /55/. Directivities according to ÖAL 28 on the Directivity dialog After withdrawal of ÖAL 28 guideline (replaced by ÖNORM ISO 9613-2) a so-called „instruction note for modeling the sound propagation according to ÖNORM ISO 9613-2: 2008 and ÖNORM EN 12354-4: 2001-02-01“ /62/ emphasizes that the guideline regarding the specifications for sound radiation „is still valid“. Furthermore, it has been clarified that the directivity correction for elements just „applies to elements with low bending stiffness while „... for heavy building elements no specific directivity correction has to used“ (translated from German). The instruction note refers to the amendment of ÖAL 28 guideline from February 2001 as mentioned before. In CadnaA there are three ÖÄL specific directivities available: • Element (ÖAL28): according to edition December 1987 • Opening (ÖAL28): according to edition December 1987 • Element (ÖAL28/01): according to amendment ÖAL28, February 2001 CadnaA - Reference Manual 2 60 2 Chapter 2 - Sound Sources 2.2.2 Sound Radiation from Elements & Openings Directivity Correction L 2 Directivity with angle (hatched: radiating surface) Depending on the angle referring to the surface normal the following expressions for the directivity correction L apply: Directivity of elements, edition 1987 85 135 : L 3 3 dB 42.5 L 3 10lg 0.4 90 3 dB 135 180 : L 10 dB 0 85 : Directivity diagram (surface normal pointing in direction 0°): CadnaA - Reference Manual 2 61 Chapter 2 - Sound Sources 2.2.2 Sound Radiation from Elements & Openings 0 85 : 85 107.5 : L 0 dB L 10lg 0.4 90 3 dB Directivity of elements with low bending stiffness, edition 2001 107.5 180 : L 10 dB Directivity diagram (surface normal pointing in direction 0°): 0 45 : L 4 dB 85 135 : 90 L 6lg dB 10 L 2 6 lg 0.4 90 3 dB 135 180 : L 10 dB 45 85 : CadnaA - Reference Manual Directivity of openings, edition 1987 2 62 2 Chapter 2 - Sound Sources 2.2.2 Sound Radiation from Elements & Openings Directivity diagram (surface normal pointing in direction 0°): 2 Application In practice, radiating elements and openings are parts of the outer envelope of buildings. In this case, the directivity vector is by default directed automatically (see chapter 2.2, section "Automatic orientation depending on source type"). CadnaA - Reference Manual Chapter 2 - Sound Sources 2.2.3 Frequency-dependent Directivity 2.2.3 2 63 Frequency-dependent Directivity Besides of the predefined directivities user-defined frequency dependent directivities can be entered in CadnaA and be assigned industrial sources. To this end, select from the on the Tables|Libraries (local) menu the library Directivity. Insert a new row via the table‘s context menu and double-click into this line to open the dialog. Dialog Directivity containing no data The dialog shows a table in which the directivity index can be entered in octave bandwidth from 31.5 Hz to 8000 Hz at increments of 15 degrees. The directivity pattern is axial-symmetrical in a plane, pointing in forward direction (0 degrees). The directivity vector can be freely oriented on dialog Directivity of each industrial source (by specifying the xyz coordinates of the directivity vector, see chapter 2.2). In case the directivity index is unknown for certain angles, the respective input boxes remain empty. After closing the dialog, CadnaA adds the missing angular steps by linear interpolation. CadnaA - Reference Manual 2 64 2 Option „normalized“ 2 Chapter 2 - Sound Sources 2.2.3 Frequency-dependent Directivity With the option „normalized“ activated, the directivity correction is increased or reduced by a constant factor for all directions in a way that the sound power level specified on the source dialog remains unchanged with this directivity selected. This option enables to enter octave band sound pressure levels having been measured in the vicinity of the source. In this case, the entered values are not changed, but maintained. Paste Clicking the „Paste“ button enables to paste data formatted as text (ASCII format) with tabulators (TAB) as separators for columns and RETURN for rows from the clipboard into the dialog table. The data may either use decimal points or decimal commas. The data is always inserted starting from the upper left cell (0° at 31.5 Hz). The current cursor location is not relevant. Therefore, the data should be formatted correctly by inserting missing octaves or angular steps by empty columns or rows. Import of directivities via ODBC Directivities can also be imported via the ODBC connection (see chapter 7.3). To this end, select from the dialog File|Database|Definition the object type „Directivity“ (at the end of the list). The attribute of the directivity index has the structure „Sxxx_yyyy“ where: • • xxx: angle 0 to 180 degrees yyyy: frequency 31 to 8000 Hz CadnaA - Reference Manual 2 65 Chapter 2 - Sound Sources 2.2.3 Frequency-dependent Directivity In the following, the level distribution of an engine test run at an aircraft has been pasted via the clipboard: Example 2 Frequency-dependent directivity index in 30° steps. No data is available for the remaining angular steps. After closing and reopening the dialog the missing angular steps have been updated by interpolation: Frequency-dependent directivity index, missing angular steps have been filled in by interpolation CadnaA - Reference Manual 66 2 Chapter 2 - Sound Sources 2.2.3 Frequency-dependent Directivity In order to assign this directivity click the „Directivity“ button on the edit dialog of a point, line or area source and select the given name of the directivity from the list box „Directivity“. 2 Selecting the directivity Detailed Example see chapter 6.3.3 "Frequency Dependant Directivities" in the manual „Introduction to CadnaA“ CadnaA - Reference Manual 2 67 Chapter 2 - Sound Sources 2.3 Tennis - Point-of-Serve 2.3 Tennis - Point-of-Serve The noise by tennis courts, especially when multiple courts are operated simultaneously, consists of a sequence of short impulses resulting from the impact of the tennis balls, causing an increased annoyance. In the German legislation, the assessment of noise caused by sports facilities is characterized by the A-weighted maximum level LpAFT during a time interval of 5 seconds. This maximum level for each interval of 5 seconds corresponds with the maximum level applying the time weighting „FAST“ /107/. The tennis source in CadnaA is a point source the emission of which is not entered, but set automatically /42/. For the calculation of propagation the selected industrial standard/guideline is used. With ISO 9613-2 it shall be noted that the non-spectral ground attenuation has to be selected (see chapter 6.2.9.1, section "Ground Attenuation"). In this case, the ground reflection is considered automatically by the directivity index K0 or D resp. based on the source height above ground (corresponding to K0=3 dB as stated in VDI 3770 /42/). 2 Since the emission of the tennis source refers specifically to the assessment procedure established by the German legislation, it has to be decided whether this type of source is applicable in other countries and in a different legal context. CadnaA - Reference Manual Tennis Source 68 2 2 Source in SteadyState / Operating Time Chapter 2 - Sound Sources 2.3 Tennis - Point-of-Serve By default, the option „Source in Steady-State“ is selected where no correction for operating time applies. In this case, the specified noise emission is constant for each entire daily period (see chapter 6.2.4). Dialog Tennis - Point-of-Serve, with option „Source in Steady-State“ By selecting the option „Operating Time“, the source-specific operating time in minutes can be entered for each daily period „Day|Recreation (=Evening)|Night“. The correction for operating time result from the operating times and the reference time intervals D|E|N specified in the configuration of calculation (see chapter 6.2.4). Dialog Tennis - Point-of-Serve, with option „Source in Steady-State“ Addressing Diurnal Patterns Furthermore, diurnal patterns (= hourly emission profile covering 24 hours) can be used for the tennis source in CadnaA. To this end, first define a diurnal pattern with the application type „Industry“ in the local or the global library „Diurnal Patterns“ (see chapter 12.3). Subsequently, this diurnal pattern can be selected from the list box. CadnaA - Reference Manual 2 69 Chapter 2 - Sound Sources 2.3 Tennis - Point-of-Serve When tennis is played during the entire period for Day/Recreation (Evening)/Night the option „Source in Steady-State“ is used. Evaluation 2 Only when tennis is played just for a part of a period, the operating time and the reference time on tab „Reference Time“ (see chapter 6.2.4) have to be specified. The result is then displayed for the first evaluation parameter (Ld). Alternatively, a diurnal pattern could be used in the evaluation. Whether this is more useful or not, depends on the local legal prescriptions made. If the official approval just depends on a set of sensitive hours (e.g during Sundays or public holidays) the evaluation of just this period may be sufficient (i.e. not requiring to use diurnal patterns). It is useful to name the courts and the points of serve properly (and the ID). CadnaA - Reference Manual Example 70 2 Geometry 2 Chapter 2 - Sound Sources 2.3 Tennis - Point-of-Serve Per default, the source height is 2 m above ground (according to VDI guideline 3770 /42/). The points of serve are entered on the middle of the base line of a tennis court. Hier den Tennisaufschlagpunkt plazieren When modeling playing doubles in tennis, not twice as many points-ofserve are entered, as the number of events does not depend on the type of game. According to /42/, each tennis point-of-serve gets a sound power level assigned which depends on the distance to the receiver. This approach requires to sort the sources for each receiver by distance source-receiver and to assign the respective sound power level. This sorting and allocation occurs automatically when using the tennis source. This emission model is not consistent with other (industrial) sources where constant emission is assumed. The emission model considers the fact that points-of-serve being closer to or unscreened with respect to the receiver point dominate the noise level, while more distant or screened points-of-serve are less or not relevant. CadnaA - Reference Manual 2 71 Chapter 2 - Sound Sources 2.3 Tennis - Point-of-Serve The following approach is used to address the emission automatically: • For each source Q1..Qn the total attenuations Rn,i are determined for each receiver i: Rn,i = PWLn - SPLn,i The total attenuations Rn,i are evaluated using the industrial guideline selected in CadnaA. • Sorting of the source points where source Q1 has the smallest attenuation and Qn the largest one. For unobstructed propagation this procedure corresponds to a sorting by distance source-receiver. • The sources Q1 to Qn are given the following sound power levels. n PWLn 1 2 3 4 5 6 7 8 9 10 89.8 88.2 86.7 85.1 83.6 82.0 80.5 78.9 77.4 75.8 The emission of the tennis source does not depend on the daily period D/E/N. These values apply also when doubles is played. • Energetic addition of all levels at each receiver. Even with grid calculations, just the 10 closest tennis sources cause a noise impact at each grid point (assuming free propagation). CadnaA - Reference Manual Emission Model (detailed) 2 72 2 Example 2 Chapter 2 - Sound Sources 2.3 Tennis - Point-of-Serve The following example shows 8 tennis courts with 16 points-of-serve. In the calculation, just the 10 sources closest to the receiver contribute. The emission from more distant sources is irrelevant at this receiver. Examples\ \02_Sources\Tennis\ tennis.cna By replacing these 10 tennis sources by point sources and addressing the distance-dependent sound power levels as from the table, would result in the same receiver level. Simplified Emission Model The simplified emission model described in the VDI guideline 3770 /42/ uses point sources at each point-of-serve, all having a (constant) A-weighted sound power level of PWL=90 dB(A) (at 2 m height). This simplified approach leads, however, to an overestimation of the receiver levels compared with the detailed emission model described above. So, in case limiting values are satisfied using the simplified emission model they will be as well using the detailed emission model. CadnaA - Reference Manual Chapter 2 - Sound Sources 2.4 Roads 2.4 Roads The sound source „Road“ is radiating to all sides as long as the option „SelfScreening“ is not activated (see chapter 2.4.1 "Common Input Data", section "Self-Screening"). Radiation from sound source „Road“, relative height 0 m (for RLS-90) Radiation from sound source „Road“, relative height 10 m, option „Self-Screening“ deactivated Radiation from sound source „Road“, relative height 10 m, option „Self-Screening“ activated The object „Road“ may have different values at each polygon point for the following parameters: • • • 2 73 the road’s cross section or width (see chapter 2.4.1, section "Specification of Road Width") the lateral slope (see chapter 2.4.1), and the height (see chapter 4.2). CadnaA - Reference Manual 2 74 2 2 Chapter 2 - Sound Sources 2.4 Roads The command Parallel Object (see manual „Introduction to CadnaA“) on the context menu of a road enables to generate barriers, embankments, or contour lines at a specified distance parallel to the road’s axis or to generate station marks into the direction of the road using the command Generate Station (see manual „Introduction to CadnaA“). Commands on the context menu of the object „Road“ The parameters of a road are entered in edit mode on the dialog Road that opens when double-clicking on the road’s centre line. The subsequent chapters are specific for each standard or guideline available in CadnaA. These specifications do not represent a copy of the standardized procedures, rather the way they are implemented. CadnaA - Reference Manual 2 75 Chapter 2 - Sound Sources 2.4.1 Common Input Data 2.4.1 Common Input Data When clicking the file selector symbol to the right of the input box „SCS/ Dist. (m)“ in the dialog Road the dialog Road Width is displayed enabling to enter, either the distance of the center lines of the outer lanes (location of the noise sources), or the total width of the road from curb to curb (in m). Alternatively, the predefined cross sections can be selected. Roads having a road width > 0 m have two lanes whole roads with a road width = 0 m will have a single lane only. Specification of Road Width The road width represented on the screen corresponds to the entered width only in case the additional width (at the curb) is set to 0 m (see below, section "Display real Width of Roads"). In this case, the borders of the object „Road“ represent the centre lines of the outer lanes (noise sources). Distance of the outer lanes The road width displayed on screen does not correspond to the entered width because a default distance of 1.75 m is presumed between the centre lines of the outer lanes to the curb. Therefore, a road with a total width of e.g. 10 m from curb to curb has a distance of 10 - (2*1,75) = 6,5 m between the centre lines of the outer lanes. Total width of road from curb to curb On Options|Appearance menu the additional width between the emission lines and the curb can be defined globally (object type „Road“). The value entered represents the sum of the curb’s distance left/right. Mark the object „Road“, select the first type of layer „Simple“, and enter the required additional width. Display real Width of Roads CadnaA - Reference Manual 2 76 2 Chapter 2 - Sound Sources 2.4.1 Common Input Data 2 Appearance dialog for object type „Road“: additional width for distance to curb Via the second type of layer „Simple“ the appearance of the centre lines of the outer lanes (sound source locations) can be defined. The settings concern all roads globally. Appearance dialog for object type „Road“: for sound source appearance CadnaA - Reference Manual Chapter 2 - Sound Sources 2.4.1 Common Input Data 2 77 The centre line of the object „Road“ will always be displayed as a centre line, irrespective whether the real road has a single or several lanes in each direction (e.g. highway). 2 Road with additional width: emission lines and curbs Standard Cross Section (SCS) The standardized cross sections can be selected from the list with the mouse and clicking OK. The standardized cross sections result from the following German standards: • Richtlinien für die Anlage von Straßen RAS, Teil: Querschnitte RAS-Q, Ausgabe 1982 /18/ und 1996 /19/, Forschungsgesellschaft für Straßenund Verkehrswesen, Arbeitsgruppe Straßenentwurf, Köln. • Entwurfshinweise für planfreie Knotenpunkte an Straßen der Kategoriengruppe B, RAS-K-2-B, Ausgabe 1995 /21/. • Aktuelle Hinweise zur Gestaltung planfreier Knotenpunkte außerhalb bebauter Gebiete, AH-RAL-K-2, Ausgabe 1993 /22/. CadnaA - Reference Manual 78 2 Examples for Roads 2 Chapter 2 - Sound Sources 2.4.1 Common Input Data In the subsequent section some examples are given for the input of roads. Example 1: Single Lane Road For a single-lane road, enter 0 in the input box „Standard Cross Section/Distance“ on the dialog Road or, if 0 is displayed as the default value, leave it unchanged. In this case just a single emission line exists. Example 2: Multi-lane Road For a multi-lane road, enter either the distance between the centre lines of the outer lanes, or select the appropriate predefined cross section. For example, when selecting the standard cross section „a6ms“ according to RAS-Q 82 / 18/, a distance of 24.75 m results between the centre lines of the two outer lanes. This corresponds to the road width displayed on the screen (with an additional width of 0 m). Example 3: Road widening from 1 to 2 Lanes In order to alter the distance of the outer lanes or the lateral slope along a road, each polygon point is edited individually via the dialog Geometry (see chapter 4.2). Proceed as follows. • Open the dialog of the respective road. • Click the button „Geometry“ and double-click into a row of the geometry list. CadnaA - Reference Manual Chapter 2 - Sound Sources 2.4.1 Common Input Data 2 79 2 Dialog Road: Point • On the dialog Road: Point, enter the appropriate values for the distance between the axis’ of the outer lanes. • Access the next or previous polygon point via the arrow buttons. Via the button „New“ a new point is inserted. The road’s polygon point being edited is flashing on the screen. In order to see this, the dialog box may have to be moved apart. To keep the road width constant in the direction of geometry, it does not require to edit every polygon as the entered distance is kept until it is changed at a further point. Widening of a road from 1 to 2 lanes CadnaA - Reference Manual 80 2 Example 4: Crossing with continuous lanes Chapter 2 - Sound Sources 2.4.1 Common Input Data The next example shows a crossing with continuous lanes. 2 In CadnaA, just enter the two intersecting roads. In case the traffic densities of the four combining road sections are different, it needs to model this road crossing from four road sections joining in the middle of the crossing. Regarding the use of traffic lights see chapter 2.5. Even when two road sections each are supposed to join in the middle of the crossing, the straight through-lanes are entered first and can be split afterwards. Splitting of Roads into Sections Option 1: Open the context menu by clicking on the centre line of the road with the right mouse button. Selecting the command Break Lines from the context menu splits the crossing roads right in the middle. This can be checked by clicking on the split road selecting just a half of it. Subsequently, by clicking one of the split road sections, select the command Break Lines once again, the non-split road will be split. Deactivate other objects - if any - being intersected by the roads in order not to be split as well. CadnaA - Reference Manual Chapter 2 - Sound Sources 2.4.1 Common Input Data 2 81 If this is the case, and the other objects shall not to be split, proceed as follows. 2 Option 2: Instead of using the crossing roads as intersection lines for splitting, draw an auxiliary line - for example, a line source or an auxiliary polygon - on top of the centre line of the road to be split, and apply the command Break Lines from the context menu of this auxiliary line in order to split the road. Then, delete the auxiliary line. After splitting of the roads, different parameters such as traffic densities can be defined for the individual road sections. for further options see the manual „Introduction to CadnaA“. Example 5: Crossing with Filter Lane This example is a combination of the scenarios already dealt with. At the transitions from the two-lane roads to the crossing and within the area of the crossing, the lanes are modeled from roads with a road width of zero. These are followed by two-lane roads in all four directions. Any other geometry may be derived from those examples. CadnaA - Reference Manual 82 2 Lateral Slope 2 Chapter 2 - Sound Sources 2.4.1 Common Input Data On the dialog Road: Point, the lateral slope can be defined - besides the outer lanes’ distance - from point to point (via button „Geometry“ of the road). The lateral slope refers to the outer lanes’ axis which is rotated around the road’s centre line. A positive value lifts the outer right lane, a negative value the outer left lane. „Right“ and „left“ refer to the initial point when looking towards the final point. Emission in dB(A) The entered slope holds also for all subsequent points into the direction of geometry. A new value needs to be entered only when the lateral slope changes again at a further point. Starting from this point, this new value holds again for all subsequent points. The sound emission of a road is characterized by an emission level which is usually specific to the standard or guideline applied. This value is either entered directly or derived from road specific parameters for the selected road standard or guideline (see subsequent chapters specific to each standard/ guideline). Traffic Density Counts, MDTD Average daily traffic density (normally: vehicles per 24 hours): This is the number of vehicles passing a section of the road per day, averaged over the entire year. Road Type With the option „Counts“ selected, this list box enables to select the road type according to the selected standard. Based on this classification, default values for the hourly traffic density and for the proportion of trucks are used. The road types specific to the selected road noise standard can also be assigned using the attributes STRGATT or STRGATT_NR. For details, see the chapter for each road noise standards below. CadnaA - Reference Manual 2 83 Chapter 2 - Sound Sources 2.4.1 Common Input Data Further, the emission of a road can be described by a diurnal pattern containing hourly traffic data. Diurnal patterns can be defined in the global or in the local library (see chapter 12.3). After having defined a diurnal pattern in the global or local library its ID code can be selected from the list box „Road Type“. Diurnal Pattern 2 Diurnal Pattern TG_1 selected on list box „Road Type“ User-defined diurnal patterns can be assigned by using the attribute STRGATT (thus not by the attribute STRGATT_NR). When the option „Precise Counts“ is activated, the relevant hourly traffic density M (in vehicles/hour) for the periods Day|Evening|Night and the mean proportion of trucks p% can be entered (vehicles with a gross mass > 2800 kg as percentage of the relevant traffic density). CadnaA - Reference Manual Exact Count Data 84 2 Speed Limit (km/h) 2 Chapter 2 - Sound Sources 2.4.1 Common Input Data This is the maximum speed, in km/h, permissible on the relevant road section for autos and trucks. This speed is taken into account according to the selected standard for autos and trucks. The default value for trucks is the same for cars. In case a different speed limit applies for trucks, activate the check box „Truck“ and enter the speed limit for trucks. Information on the minimum and maximum speeds for each road noise standard is given in the subsequent chapters. Button DEN When clicking the symbol speed limits can be entered separately for autos and trucks and for the time periods Day|Evening|Night. Road Gradient (%) The road gradient in % can either be entered by the user or calculated automatically, respecting the individual height profile of the road. The available options are selectable from the list box „Road Gradient“. Dialog Road with list box „Road Gradient“ CadnaA - Reference Manual 2 85 Chapter 2 - Sound Sources 2.4.1 Common Input Data With selection of „Road Gradient: auto“ the gradient of roads made of several road sections is calculated automatically. In this case, the displayed emission value (e.g. Lm,E with RLS-90) does not consider any gradient correction (also, not the tabulated emission value on menu Tables|Sources|Road). The gradient correction, however, is calculated for each road section automatically and considered within the calculation of propagation. Select from the list box „Road Gradient“ into which direction the traffic flows on the two outer lanes. The abbreviations VA, AV, AA and VV designate the traffic direction on the outer lanes, as seen from the first to the last point of the road (see figure below). Road geometry and traffic directions The letter „A“ and „V“ can be understood as arrowheads. For example, in case of traffic direction VA the traffic flow is - seen from the first point of the road - on the left outer lane into the opposite direction of the geometry points and on the right outer lane into the direction of the geometry points. The type of road gradient can also be specified by using the attributes STEIG and STEIG_AUTO (see CadnaA-manual „Attributes, Variables, and Keywords“). CadnaA - Reference Manual Road Gradient auto 2 86 2 Calculate Road Gradient 2 Chapter 2 - Sound Sources 2.4.1 Common Input Data When selecting the command Calc Gradient of Roads from the Extras menu, CadnaA calculates the average gradient in % for all active roads based on their z-coordinates and the digital terrain model. The result is displayed and used as road gradient. Because the value applies for the entire road, the gradient is calculated from the height difference of the first and the last point of the road’s entire length. Otherwise, the road has prior to be broken into pieces (by the command Break into Pieces, with the option „Split at Polygon Points“) before calculating the gradient. The gradient calculation using the command Extras|Calc Gradient of Roads occurs for all active roads simultaneously. In case this is not intended, deactivate those roads which are to be excluded from the gradient’s calculation and reactivate them afterwards. Dialog Geometry Source Height The height entered in the dialog Geometry is the surface height of the road. Depending on the selected standard for road noise the source height (e.g. 0.5 m with RLS-90) is added for calculation. Thus, the road’s z coordinate is always the surface height. Self-Screening When the option „Self-Screening“ on the dialog Geometry is activated the road is just radiating into the upper half sphere. For the lower half sphere a screening effect occurs for all receivers below the road surface. This feature enables to define inclined roads, either upwards or downwards, by allocating the height above (relative) ground or an absolute height to every point of the road, and by defining an additional width (e.g. considering sidewalks etc.). Since the option „Self-Screening“ is available, the use of the object „Bridge“ became superfluous (see chapter 3.3). CadnaA - Reference Manual 2 87 Chapter 2 - Sound Sources 2.4.1 Common Input Data When selecting a predefined cross-section (see chapter 2.9.1) the respective additional width referring to the entire road profile is copied to the input boxes "Additional Width". This feature facilitates the consideration of ground absorption for the entire road width (see chapter 6.2.7). By default, the road width as displayed by CadnaA results from the sum of the width between axis of the outer lanes and the additional width as defined on dialog Options|Appearance (see also section "Specification of Road Width", default value: 3.5 m). 2 Additional Width left/ right With the self screening-option activated, the actual road width can be specified by entering an additional width > 0 m. The additional width can be defined separately for either side of a road. A specified additional width overwrites the additional width defined on dialog Options|Appearance. These additional width is also displayed in the plan view and on the 3D-special view. In addition, parapets (e.g. parallel barriers) for the self-screening road can be defined, either on one or both sides by entering a height left/right > 0 m. The parapets are treated as fully absorbing on either sides. This characteristic cannot be changed. Absorbing or reflecting barriers without or with cantilever can be defined just by using the object „Barrier“ (see chapter 3.2). The following requirements and properties are to be respected: • In any case, the additional width has to be > 0 m. • The screens defined via option „Self-Screening“ are a characteristic of the road and are not displayed in the 2D-graphics, but just on the 3D-Special view (see chapter 9.14). • Barriers defined via option „Self-Screening“ will just screen the own source (road), but not the noise from other kinds of sources. CadnaA - Reference Manual Height of Parapet left/ right 88 2 Station from/up to 2 Chapter 2 - Sound Sources 2.4.1 Common Input Data This option enables to restrict the length of the barrier along the road’s axis with reference to the stationing. In this case, the barrier is just generated for the range „from-up to“. This option is particularly useful when modeling bridges in order to suppress the diffraction around the edge of the road sections (road width) at bridgeheads. For the automatic assignment two attributes are available: • • Only for Ground Absorption, no Screening station start: station end: SSCR_ST_B SSCR_ST_E With this option being activated, the additional width entered will not cause any screening effect, but will just be considered when calculating ground absorption. This requires, however, that the respective option on the configurations is checked (dialog Calculation|Configuration, tab „Ground Absorption“, option „Roads/Parking Lots are reflecting G=0“, see chapter 6.2.7). With this option activated the speed of calculation may increase considerably due to the omission of barrier calculation. The self-screening effect of the road’s surface - including parallel barriers, if any - just refers to the respective road itself. Thus, the parallel barriers (parapets) defined via „Self-Screening“ are not seen by other sources. Additional information The height of the road source above the road‘s surface depends on the selected road noise standard. The height on the dialog Geometry of the object "Road" refers to the road surface. CadnaA - Reference Manual 2 89 Chapter 2 - Sound Sources 2.4.2 RLS-90 2.4.2 RLS-90 The emission parameter according to RLS-90 is the mean level Lm,E at 25 m distance from the road’s axis of an infinite straight road with free sound propagation /17/: Emission Parameter Lm,E = Lm + Dv + DStrO + DStg where Lm: mean level at 25 m distance Dv: speed correction DStrO: correction for road surface DStg: correction for road gradient Dialog Road (for RLS-90) The mean level Lm calculates from: Lm 37.3 10 lgM * 1 0.082 * p where M: hourly traffic, i.e. mean number of vehicles of hour Note - For multi-line roads the hourly traffic is split by 50/50 for each lane. p: portion of trucks in % (trucks with a maximum mass of more than 2800 kg) CadnaA - Reference Manual Emission Level Lm 2 90 2 MDTD - RLS-90 2 Chapter 2 - Sound Sources 2.4.2 RLS-90 Specifying the „Mean Daily Traffic Density“ (MDTD, veh/24h) calculates the emission level Lm,E depending on the road type based on the hourly traffic data M (veh/h) and the truck portion p (%) according to the table below. accord. to RLS-90, table 3: Attribute Value STRGATTNR MDTD - VBUS daytime (6-22 h) nighttime (22-6 h) M (veh/h) p (%) M (veh/h) p (%) 0 Motorway 0.06 DTV 25 0.014 DTV 45 1 Federal Road 0.06 DTV 20 0.011 DTV 20 2 Ordinary Road 0.06 DTV 20 0.008 DTV 10 3 Local Road 0.06 DTV 10 0.011 DTV 3 With the options „Strictly accord. to RLS-90“ deactivated and the option „Calculation accord. to VBUS“ activated (both on tab „Road“, menu Calculation|Configuration) the following hourly traffic data M (veh/h) and the truck portion p (%) will be used /115/: Attribute Value STRGATTNR Source Geometry Road Type Road Type Day (6-18 h) Evening (18-22 h) Night (22-6 h) M (veh/h) p (%) M (veh/h) p (%) M (veh/h) p (%) 0 Motorway 0.062 DTV 25 0.042 DTV 35 0.014 DTV 45 1 Federal Road 0.062 DTV 20 0.042 DTV 20 0.011 DTV 20 2 Ordinary Road 0.062 DTV 20 0.042 DTV 15 0.008 DTV 10 3 Local Road 0.062 DTV 10 0.042 DTV 6.5 0.011 DTV 3 The height entered in the dialog Geometry is the height of the road’s surface. The source height is 0.5 m above the road’s center line or above of the center lines of the outer lanes. CadnaA - Reference Manual 2 91 Chapter 2 - Sound Sources 2.4.2 RLS-90 The minimum speed according to RLS-90 is 30 km/h for all types of vehicles. The speed limits are 130 km/h for autos and 80 km/h for trucks. In case a speed below 30 km/h is entered, 30 km/h is applied instead. With a speed limit > 130 km/h a speed of 130 km/h for autos and of 80 km/for trucks is used. Speed Limit (km/h) 2 The speed correction Dv calculates from: 100 100.1D 1 p Dv Lcar 37.3 10 lg 100 8.23 p with Lcar 27.7 10 lg 1 0.02vcar 3 and D Ltruck Lcar where Ltruck 23.1 12.5 lg vtruck where vcar: speed limit for autos/cars (30<=vcar<=100 km/h) vtruck: speed limit for trucks (30<=vcar<=80 km/h) Lcar, Ltruck: mean level Lm for a one auto/car or truck per hour p: proportion of heavy vehicles (in %) The correction for different road surfaces DStrO can be entered or selected from the list box providing the road surface types of RLS-90. To this, at first the corresponding option button has to be activated. By default, the road surfaces listed in a following table are available. CadnaA - Reference Manual Road Surface 92 2 Chapter 2 - Sound Sources 2.4.2 RLS-90 accord to RLS-90, table 4, and amendment (Rundschreiben Straßenbau Nr. 14/1991, Ed.: BMV): 2 Attribute Value STRONR *) DStrO in dB(A) at a speed of Road Surface < 40 km/h < 50 km/h <= 60 km/h > 60 km/h 1 smooth mastic asphalt, asphalt concrete or blinded mastic asphalt 0 0 0 0 2 concrete or corrugated mastic asphalt 1 1,5 2 2 3 pavement with a smooth surface 2 2,5 3 3 4 other pavements 3 4,5 6 6 5 concrete according to ZTV Beton 78 with steel broom stroke - - - 1 6 concrete according to ZTV Beton 78 with steel broom stroke and with smoothing tool - - - -2 7 asphalt concrete <= 0/11 and blinded mastic asphalt 0/8 and 0/ 11 without grit - - - -2 8 open-pore asphalt covering layers containing at least 15 % of voids, when new, with 0/11 grain size - - - -4 9 open-pore asphalt covering layers containing at least 15 % of voids, when new, with 0/8 grain size - - - -5 Notes: 1. For low-noise road surface materials which have proved to provide a lasting noise reduction due to recent technological developments in structural engineering, different DStrO corrections may be taken into account. 2. The corrections for rows 5 to 9 apply just to roads outside towns with a speed limit > 60 km/h. 3. The classes for the speed limit have been rearranged for software design reasons. *) The attribute value STRONR=0 selects the numerical input of DStrO. CadnaA - Reference Manual 2 93 Chapter 2 - Sound Sources 2.4.2 RLS-90 The road gradient g can be entered in % or be calculated automatically, depending on the z-heights of the road. The list box „Road Gradient“ on the Road dialog offers different options (see chapter 2.4.1, section "Road Gradient (%)"). DStg 0.6 g 3 for |g| > 5% DStg 0 for |g| <= 5% First-order reflections are to be taken into account by first-order mirror sound sources according to RLS-90. When the option „Strictly according to RLS-90“ on the tab „Road“ (Calculation|Configuration menu, see Chapter 6.3.11) is activated, this occurs automatically. This is also the case if a different order of reflection is specified on the tab „Reflection“ (see Chapter 6.3.9). A calculation without any reflections can be engaged only by deactivating the option „Strictly according to RLS-90“ and specifying no order of reflection (i.e. zero). Gradient (%) 2 Correction for Multiple Reflections With building rows on both sides of a road, the resulting excess level has to be accounted for by an additional correction for multiple reflections which depends on the average height of the buildings left/right and on the distance among them. According to RLS-90 a correction for multiple reflections applies only when percentage of gaps between the buildings is less than 30%. This is the excess sound level due to multiple reflections. When this option is activated a correction (in dB) for multiple reflections can be entered. Alternatively, the correction is calculated from the average height of the buildings on each side of the road, and the average distance (in m) between the buildings on both sides of the road according to: between reflecting buildings (percentage of gaps < 30%): Drefl 4 * hBeb / d Beb 3.2 dB CadnaA - Reference Manual Drefl 94 2 Chapter 2 - Sound Sources 2.4.2 RLS-90 between absorbing buildings: Drefl 2 * hBeb / d Beb 1.6 dB 2 between highly absorbing buildings: Drefl 0 dB Average Height (m) average height of the buildings (attribute HBEB) Distance (m) average distance between the buildings (attribute ABST) Absorption absorption of the buildings (reflecting, absorbing or highly absorbing). According to RLS-90, the correction for multiple reflections - when specified - is applied independently from the receiver’s distance. In CadnaA, the correction for multiple reflections is considered in the road’s emission level (see calculation protocol). CadnaA - Reference Manual 2 95 Chapter 2 - Sound Sources 2.4.2 RLS-90 The command Calc Width of Roads (Extras menu) calculates the average height, the average distance and the proportion of gaps between buildings parallel to the roads. The results are stored in string variables stored on the dialog Memo-Window of the corresponding road.. DBEB_L; DBEB_R average distance between the buildings (left/right) HBEB_L; HBEB_R average height of the buildings (left/right) LUECK_L; LUECK_R percentage of gaps (left/right) Calc Width of Roads 2 Dialog Memo-Window with the corresponding string variables after using the command Calc Width of Roads. By copying those values to the respective input boxes on dialog Road the Correction for Multiple Reflections can be evaluated using CadnaA (see subsequent example). • Open the file XL_01.cna. Examples\05_Immis- • Select the command Calc Width of Roads (from Extras menu) sions\Option XL\XL_01.cna First, the calculated average height of the buildings is copied to the input box „Average Height (m)“ on the dialog Road. To achieve this, the values of the string variables HBEB_L (average height, left) and HBEB_R (average height, right) are used. Both values are summed up and divided by 2. Proceed as follows: CadnaA - Reference Manual Example 96 2 2 Chapter 2 - Sound Sources 2.4.2 RLS-90 • Click with the right mouse onto the white area of the screen and select from the context menu the command Modify Objects. • On the dialog Modify Objects specify the action „Change Attribute“ for the object type „Road“ and confirm by OK. • On the subsequent dialog select the attribute HBEB, activate „Arithmetic“ and enter the following expression: (MEMO_HBEB_L+MEMO_HBEB_R)/2 CadnaA - Reference Manual Chapter 2 - Sound Sources 2.4.2 RLS-90 • 2 97 When confirming by OK the calculated value is copied to the box „Average Height (m)“ on the dialog Road. 2 Still, the distance between the buildings (DBEB) has to be copied as well. • Select from the dialog Modify Attribute the attribute ABST and enter following formula: MEMO_DBEB_L + MEMO_DBEB_R CadnaA - Reference Manual 98 2 Chapter 2 - Sound Sources 2.4.2 RLS-90 Now, CadnaA calculates from the entered data the correction for multiple reflections. 2 As already said, whether the correction for multiple reflections applies or not depends whether the proportion of gaps is smaller than 30%. • In order to consider this in CadnaA, reselect on the dialog Modify Objects the action Modify Attribute for object type „Road“. • On dialog Modify Attribute select the attribute DREFL and enter the following formula (with option „Replace Strings“): iif(max(MEMO_LUECK_L,MEMO_LUECK_R)<0.3,DREFL,0) This expression means in words: If the maximum value of the string variables MEMO_LUECK_L and MEMO_LUECK_R is smaller than 0.3 (= 30%) keep the value of DREFL, otherwise, replace it by zero (see also manual „Attributes, Variables, and Keywords“, chapter "Chapter 5 - Operators & Functions"). After confirming the dialog with OK the option „Drefl“ is activated and the proportion of gaps entered if the condition above is fulfilled. Otherwise, Drefl= 0 dB and no correction of multiple reflections is applied. CadnaA - Reference Manual Chapter 2 - Sound Sources 2.4.2 RLS-90 Using the command Long Straight Road from the context menu of a road (or from the Extras menu) enables to perform an approximative calculation of the receiver level along roads complying with the requirements of RLS-90, section 4.4.1 („infinite long straight road“). This calculation cannot be used in combination with the other calculation methods from RLS-90 (segmented road sections). When selecting the command Long Straight Road a dialog is displayed calculating the sound emission levels LmE,Day and LmE,Night as well as the receiver levels Lr,Day and Lr,Night. Both receiver levels are calculated when entering the relevant parameters. Dialog Long Straight Road (accord. to RLS-90) CadnaA - Reference Manual 2 99 Long Straight Road 2 100 2 Chapter 2 - Sound Sources 2.4.2 RLS-90 The relevant distances and object heights are shown in the following figures. 2 ground plan: sectional view: CadnaA - Reference Manual 2 101 Chapter 2 - Sound Sources 2.4.2 RLS-90 In case the emission of the road where the context menu command Long Straight Road has been selected is specified already, the respective emission levels Lm,E for Day/Night are displayed. Lm,E Day/Night 2 The calculator symbol enables to alter the emission data via the dialog Road. Alternatively, after activation of the check box, the emission level Lm,E for Day/Night can be entered. In the latter case, the road width or the standard cross section are specified on the dialog. Road Width/Standard Cross Section The object heights (for road, reflector, obstacle, and receiver point) can be specified as relative or absolute heights. relative/absolute Height Using this form, the height of a barrier (obstacle) can be calculated when a limiting value has be entered in box „Lr Goal“. Calculate Height of Obstacle Here, the required excess length of the screening obstacle is displayed. This additional length in direction of the road to both sides - counted from the perpendiculars of the obstacle to the road line - is required at least in order to ensure that the calculated receiver levels are met. Excess Length Via the button „Save“ the calculation results can be saved and be loaded via the button „Open“. The file extension used is *.lgs. Save/Open The form will be printed using the definitions of the selected template file to the connected printer. Print This button exports the form using the definitions of the selected template file as a RTF-file, e.g for MS-Word. Export A template file can be selected specifying the output format (file suffix *.rtf). The template files delivered with CadnaA are stored in the directory templates in the CadnaA-installation directory. To create your own template file, copy an existing template file and alter the text and the format definitions as required. The variable names can be obtained from the provided template files. Template CadnaA - Reference Manual 102 2 Chapter 2 - Sound Sources 2.4.2 RLS-90 2 CadnaA - Reference Manual Chapter 2 - Sound Sources 2.4.3 Nordic Prediction Method 1996 2.4.3 Nordic Prediction Method 1996 Two types of evaluation parameters are calculated by the Nordic Prediction Method (NPM) for road noise (TemaNord 1996:525/73/): • the A-weighted equivalent continuous sound pressure level LA,eq and • the A-weighted maximum sound pressure level LAFmax. Further, the number of events NATd/NATn above a threshold level - as prescribed by Swedish law /76/ - can be calculated. Since the equivalent continuous level LA,eq is calculated per day (24 h) no specific day- or nighttime values exist in NPM. It is stated, however, that any other period could be assessed as well using LA,eq provided the traffic data refers to this period. In contrary, a separate procedure is applied to calculate the maximum level LAFmax. 2 103 In CadnaA, the emission level LAeq*,10m as shown on the dialog Road refers to the A-weighted equivalent continuous sound pressure level LA,eq as emission parameter, corrected for the road surface and for the road gradient. When calculating the A-weighted maximum sound pressure level LAFmax the emission parameter shown is still the level LAeq*,10m. Dialog Road (for Nordic Prediction Method) CadnaA - Reference Manual 2 104 2 Emission Level LA,eq 2 Chapter 2 - Sound Sources 2.4.3 Nordic Prediction Method 1996 The A-weighted equivalent continuous sound pressure level LA,eq at 10 m distance from the road’s axis of an infinite straight road with free sound propagation calculates from the sound exposure levels for each vehicle category (light and heavy traffic): • level for light traffic: LAeq ,10 m light LAE ,10 m light 10 lg • N light T dB(A) level for heavy vehicles (m > 3500 kg): LAeq ,10 m heavy LAE ,10 m heavy 10 lg N heavy T dB(A) and for both contributions: LAeq,10 (mixed) = LAeq,10 (light) ++ LAeq,10 (heavy) where ++ represents the energetic sum. The sound exposure levels for each category result from: • light traffic: v >= 40 km/h: LAE ,10 m 73.5 25 lg v dB(A) 50 30 <= v < 40 km/h: LAE ,10 m 71.1 dB(A) • heavy vehicles (m > 3500 kg): 50 km/h <= v <= 90 km/h: LAE ,10 80.5 30 lg v dB(A) 50 30 <= v <= 50 km/h: LAE ,10 m 80.5 dB(A) and LAE ,10 m v 30 km / h LAE ,10 m v 30 km / h CadnaA - Reference Manual 2 105 Chapter 2 - Sound Sources 2.4.3 Nordic Prediction Method 1996 The calculation of the A-weighted maximum sound pressure level LAFmax makes use of the percentage X% of the vehicles (light & heavy) exceeding this level (see chapter 6.2.10.2). Emission Level LAFmax The arithmetic mean level L AFma x X%,10m due to an exceedance by X% of the vehicles calculates from equations 2.29 to 2.33 in Part 2 of /73/ using a numerical approximation of the normal distribution function (to obtain y(X%) ): LAFmax X%, 10m • 2 for light traffic: v >= 30 km/h: L AFma x X %,10m 69 30 lg v y X% Sigma L ight dB(A) 50 with Sigma Light 5.5 e 0 .7 v 50 dB and L AFmax,10m v 30 km / h L AF max,10m v 30 km / h • for heavy vehicles (m > 3500 kg): v > 50 km/h: L AFm ax X %,10m 75 30 lg v y X% Sigma Heavy dB(A) 50 with Sigma Heavy 10 e v 0. 9 50 dB v <= 50 km/h: L AFmax X%,10m 75.0 y X% Sigma He avy dB(A) with Sigma Heavy 4.1 dB The level LAFmax exceeded by 5% of the vehicles calculates with a factor of y(5%)=1.64. Example When calculating the maximum level the CadnaA protocol still shows the results for the Leq calculation and thus does not apply. Protocol with LAFmax CadnaA - Reference Manual 106 2 NATd/NATn 2 Chapter 2 - Sound Sources 2.4.3 Nordic Prediction Method 1996 Swedish law /76/ prescribes to check, besides the maximum level itself, • whether a maximum level of 70 dB(A) is exceeded more than 5 times for each hour during daytime (16 hours, so 16*5=80 exceedances during the entire daytime), and • whether a maximum level of 70 dB(A) is exceeded more than 5 times within the entire night-time (8 hours), and • whether a maximum level of 80 dB(A) is not exceeded at all times. This evaluation can be achieved by using the evaluation parameters NATd (for Day) and NATn (for Night), see chapter 6.2.5 "Evaluation Parameters Tab", and by specifying the length of the Day (16 h) and Night (8 h) periods, see chapter 6.2.4 "Reference Time Tab". Further, a threshold level has to be specified on the „Road“ tab (see chapter 6.2.10.2). As long as traffic count data Day/Night is used (MDTD, N/p%, or diurnal pattern) the number of events above the entered threshold level NATd/ NATn is calculated from the hourly traffic counts. Examples\ 02_Sources \Road\ Nordic 96 Results when checking for more than 80 exceedances above 70 dB(A) during daytime (16 h) Results when checking for more than 5 exceedances above 70 dB(A) during night-time (8 h) NOTE - Consider that the values displayed inside the building evaluation symbol refer to the first two evaluation parameters (here 1:Ld, 2:Ln, while 3:NATd, 4:NATn). CadnaA - Reference Manual 2 107 Chapter 2 - Sound Sources 2.4.3 Nordic Prediction Method 1996 The „Mean Daily Traffic Density“ (MDTD, vehicles/24h) does not exist in NPM as an input parameter for traffic data. Nevertheless, this feature is provided by CadnaA applying the road types of the Austrian road noise standards RVS 3.02 /59/ and RVS 4.02 /60/. The respective data is given in the tables below. from RVS 4.02, tables 1 and 2: Attribute Value STRGATTNR Road Type Day (6-19 hrs) Evening (19-22 hrs) Night (22-6 hrs) N (veh/h) p (%) N (veh/h) p (%) N (veh/h) p (%) 2 national road 0.060 * MDTD 10 0.036 * MDTD 15 0.014* MDTD 25 3 local road 0.064 * MDTD 10 0.029 * MDTD 10 0.010 * MDTD 10 4 main road 0.062 * MDTD 10 0.035 * MDTD 5 0.011 * MDTD 10 5 service road 0.062 * MDTD 5 0.041 * MDTD 2 0.009 * MDTD 2 from RVS 3.02, tables 1 and 2: Attribute Value STRGATTNR Road Type Day (6-22 hrs) Night (22-6 hrs) N (veh/h) p (%) N (veh/h) p (%) 0 local 3.02 0.065 * MDTD 10 0.007 * MDTD 5 1 national 3.02 0.065 * MDTD 15 0.013 * MDTD 25 where N: number of vehicles per hour p: percentage of heavy vehicles Speed correction in RVS refers, as it does in NPM, to 50 km/h. CadnaA - Reference Manual MDTD 2 108 2 Chapter 2 - Sound Sources 2.4.3 Nordic Prediction Method 1996 For the percentage of light/heavy trucks it holds for both (see RVS 3.02, tab. 3 and RVS 4.02, tab. 3): 2 Road Type Percentage of Heavy Vehicles light trucks (%) heavy trucks (%) national (4.02 & 3.02) 25 75 local (4.02 & 3.02) 90 10 main road 60 40 service road 95 5 Source Geometry The height entered in the dialog Geometry is the height of the road surface. The source height is 0.5 m above the road’s center line or above the center lines of the outer lanes. Speed Limit (km/h) According to NPM the real speed is used in the prediction, not the indicated speed limit. When the real speed is, however, not available the „posted speed“ should be used instead. Road Surface In CadnaA, the emission level is corrected with different road surfaces, even when NPM originally states this correction to be a part of the propagation model. The following table lists the types of road surfaces and their respective level corrections. CadnaA - Reference Manual 2 109 Chapter 2 - Sound Sources 2.4.3 Nordic Prediction Method 1996 road surface corrections according to NPM, Annex A, Table A1: Attribute Value STRONR Correction in dB(A) for a certain % of heavy vehicles Road Surface 0-60 km/h 61-80 km/h 80-130 km/h 0-5 6-19 20-100 0-5 6-19 20-100 0-5 6-100 ref 1 1a Asph.concr. (12-16mm) ref ref ref ref ref ref ref 2 1b Asph.concr. (12-16mm) 0 0 -1 -2 -1 -1 -2 -2 3 2a Asph.concr. (8-10mm) 0 0 0 -1 0 0 -1 -1 4 2b Asph.concr. (8-10mm) -1 -1 -1 -2 -1 -1 -2 -2 5 3a Mastic asph. (12-16mm) 0 0 0 1 0 0 1 0 6 3b Mastic asph. (12-16mm) 0 0 0 1 0 0 1 0 7 4a Mastic asph. (8-10mm) -1 -1 0 -1 -1 -1 -1 -1 8 4b Mastic asph. (8-10mm) -2 -1 0 -2 -2 -1 -2 -2 9 5 Chipped asphalt (BCS) 1 0 0 2 1 0 2 1 10 6a Chip seal Y1 (16-20mm) 1 0 0 2 1 0 2 1 11 6b Chip seal Y1 (16-20mm) 2 1 0 3 1 0 2 1 12 7a Chip seal Y1 (10-12mm) 0 0 0 0 0 0 0 0 13 7b Chip seal Y1 (10-12mm) 0 0 0 0 0 -1 0 0 14 8a Chip seal Y1 (6-9mm) 0 0 0 -1 0 0 -1 0 15 8b Chip seal Y1 (6-9mm) -1 0 0 -1 -1 -1 -1 -1 16 9a Chip seal Y2 (16-20mm) 0 0 0 1 0 -1 0 0 17 9b Chip seal Y2 (16-20mm) 1 0 0 1 0 -2 0 0 18 10a Chip seal Y2 (10-12mm) 0 0 0 0 0 -1 0 -1 19 10b Chip seal Y2 (10-12mm) 0 0 0 0 -1 -2 0 -1 20 11a Porous asph. (14-16mm) 0 0 0 -1 -1 -1 -1 -1 21 11b Porous asph. (14-16mm) --1 -1 0 -1 -1 -1 -1 -2 22 11c Porous asph. (14-16mm) -2 -2 -2 -2 -2 -3 -2 -3 23 12a Porous asph. (8-12mm) 0 0 0 -1 -1 -1 -2 -2 24 12b Porous asph. (8-12mm) -1 -1 -1 -2 -2 -2 -3 -3 25 12c Porous asph. (8-12mm) -3 -3 -3 -4 -4 -5 -5 -5 26 13 Cem.concr. (20-80mm) 2 1 1 2 2 2 2 2 27 14 Cem.concr. (12-18mm) 1 1 1 2 2 2 2 2 28 15 Cem.concr.,ground -1 -1 -1 -2 -2 -2 -1 -1 29 16 Paving Stones 3 3 2 5 4 3 5 4 30 17 Cement block pavement 0 0 0 0 0 0 0 0 CadnaA - Reference Manual 2 110 2 Gradient (%) 2 Chapter 2 - Sound Sources 2.4.3 Nordic Prediction Method 1996 In CadnaA, a varying road gradient corrects the emission level already, even when NPM originally states this correction to be a part of the propagation model. The correction for the road gradient Lst (in dB) results from: Lst 2G 3G lg1 p 100 100 where G: gradient in %o (10%o =1%) p: proportion of heavy vehicles (in %) In CadnaA, the road gradient is specified in % instead. Correction for Multiple Reflections When calculating the A-weighted maximum sound pressure level LAFmax no gradient correction is applied (even not when option „Road Gradient: auto“ is selected. NPM provides an overall correction for multiple reflection in side streets where the noise impact results from a main street (section 2.6.9 of part 2 of / 73/). As this correction alters the normal distance correction it is part of the propagation model and, thus, not part of the emission model. However, the correction Lms can be entered manually on the dialog Road, for parameter „Drefl“, with activating the configuration option „Calc exactly one Reflection Order“ (see chapter 6.2.10.2). When applying the correction for multiple reflections the maximum number of reflections calculated using image sources should be restricted to the first order. When the option „Average Height“ is selected (with option „Calc exactly one Reflection Order“ still activated) the correction for multiple reflections is calculated from the average height, the distance and the reflecting properties of the buildings according to RLS-90 (see chapter 2.4.2, section "Correction for Multiple Reflections"). CadnaA - Reference Manual Chapter 2 - Sound Sources 2.4.4 NMPB-Routes 1996 2.4.4 2 111 NMPB-Routes 1996 The emission parameter in NMPB-1996 („Nouvelle Méthode de Prévision du Bruit“) is the A-weighted sound power level per octave band LAw,i of a point-like sub-source Si in dB(A) /77/. This level calculates from: LAw,i 10 lg 10 EVL 10 lg QVL /10 10 EPL 10 lg QPL /10 20 dB 10 lg li Ri where EVL: sound power level of the light vehicles, in dB(A) QVL: traffic number of the light vehicles (max. mass m < 3500 kg), in veh/h EPL: sound power level of the heavy vehicles, in dB(A) QPL: traffic number of the heavy vehicles (max. mass m >= 3500 kg), in veh/h li: length of the sub-source Si, in m R(i): octave values of the reference spectrum for road noise, in dB(A) i: running number of octave In CadnaA, the overall traffic flow Q (in vehicles/hour) and the percentage of heavy vehicles p% is to be specified instead. The relation between those figures and the ones above are: Q QVL QPL and p% QPL Q Dialog Road (for NMPB 96) CadnaA - Reference Manual Emission Parameter 2 112 2 Emission Parameter LwA’ 2 Chapter 2 - Sound Sources 2.4.4 NMPB-Routes 1996 The emission parameter displayed on the dialog Road is A-weighted total sound power level per unit length L’Aw,i in dB(A) according to the modified equation: L' Aw,i 10 lg 10 EVL 10 lg QVL / 10 10 E PL 10 lg QPL / 10 20 dB in dB(A) Reference Spectrum This value includes the correction for the vehicle type, the type of traffic flow, the correction of road gradient and the road surface correction (see below). The values R(i) of the weighting spectrum are listed in the following table: i Frequency (Hz) R(i) in dB(A) 1 125 -14 2 250 -10 3 500 -7 4 1000 -4 5 2000 -7 6 4000 -12 CadnaA - Reference Manual 2 113 Chapter 2 - Sound Sources 2.4.4 NMPB-Routes 1996 The emission level E is taken from the following diagram: Emission Level E 2 Diagram for NMPB-specific emission parameter E (approximative) Legend (road gradient g%): Horizontal (-2% < g < 2%) Monté (g > 2%) Descente (g < -2%) Fluide continu 1.1 1.2 1.3 Pulsé non différencié 2.1 2.2 2.3 Accéléré 3.1 3.2 3.3 Décéléré 4.1 4.2 4.3 This diagram considers: • • • • two types of vehicles (light and heavy) four types of traffic flows (fluide continu, pulsé non différencié, accéléré, décéléré), three types of road gradient (horizontal, montée, descente) and the traffic speed for light and heavy vehicles. CadnaA - Reference Manual 114 2 MDTD 2 Chapter 2 - Sound Sources 2.4.4 NMPB-Routes 1996 The „Mean Daily Traffic Density“ (MDTD, vehicles/24h) does not exist in NMPB as an input parameter for traffic data. Nevertheless, this feature is provided by CadnaA applying the road types of the German road noise standard RLS-90 /15/ in conjunction with VBUS /115/. The respective data for the hourly traffic data M (veh/h) and the truck proportion p (%) is given in the next table. Attribute Value STRGATTNR Road Type Day (6-18 h) Evening (18-22 h) Night (22-6 h) Q (veh/h) p (%) Q (veh/h) p (%) Q (veh/h) p (%) 0 Motorway 0.062 * MDTD 25 0.042 * MDTD 35 0.014 * MDTD 45 1 Federal Road 0.062 * MDTD 20 0.042 * MDTD 20 0.011 * MDTD 20 2 Ordinary Road 0.062 * MDTD 20 0.042 * MDTD 15 0.008 * MDTD 10 3 Local Road 0.062 * MDTD 10 0.042 * MDTD 6.5 0.011 * MDTD 3 Source Geometry The height entered in the dialog Geometry is the height of the road’s surface. The source height is 0.5 m above the road’s center line or above of the center lines of the outer lanes. Speed Limit (km/h) The minimum speed according to NMPB is 20 km/h for all types of vehicles. The maximum speeds are 140 km/h for autos and 100 km/h for trucks. For higher speeds a speed of 140 km/h for autos and of 100 km/for trucks is used. In case a speed below 20 km/h is entered, 20 km/h is applied instead. Road Surface With NMPB, the correction for different road surfaces is already included in the emission level E. By default, the road surfaces listed in the following table are available (types „EC“ resulting from /114/). CadnaA - Reference Manual Chapter 2 - Sound Sources 2.4.4 NMPB-Routes 1996 Attribute Value STRONR Road Surface road surface correction in dB at a speed of Spectrum Type applied <= 60 km/h <= 100 km/h EC: <= 80 km/ h 1 Enrobé bitumé 1 2 Enrobé drainant 2 3 Chaussée cloutée 1 2 4 Béton lisse 1 0 5 Béton strié 1 3 6 Pavés (en ville) 1 3 101 EC: Porous surface 1 102 EC: Smooth asphalt 1 0 103 EC: Cement concrete 1 2 104 EC: Smooth texture Paving 1 3 105 EC: Rough texture Paving 1 6 0-3,5 *) -1 -2 spectrum type 1: road spectrum (see previous section „Reference Spectrum“) spectrum type 2: spectrum for „Enrobé drainant“ (see below) *) correction linearly increasing from 0 dB for 50 to 3,5 dB for 100 km/h Spectrum for road surface „Enrobé drainant“ (for = 3,5 dB(A)): i Frequency (Hz) R(j) in dB(A) 1 125 0 2 250 0 3 500 0,5 4 1000 5,5 5 2000 7 6 4000 7 CadnaA - Reference Manual 2 <= 130 km/h 0 0 2 115 3,5 -3 116 2 User-defined Road Surfaces 2 Chapter 2 - Sound Sources 2.4.4 NMPB-Routes 1996 With NMPB selected, additional road surfaces can be defined by the user. Open the local library for sound reduction indices (menu Tables|Libraries (local)|Sound Reduction Indices) and enter a new line via the table’s context menu. For a sound reduction index spectrum to be selectable as a road surface correction, the ID has to start with the text sequence: NMPB_X, where X is an integer without a leading zero (for example: NMPB_1, NMPB_11, NMPB_111, but not NMPB_01). The entered name will be shown at the end of the default list of road surfaces. Example: user-defined road surface spectrum Traffic Flow The selected type of traffic flow applies to all daily periods D/E/N. Available types are: • • • • Button DEN fluide continu pulsé non différencié accéléré décéléré Clicking this button enables to define different types of traffic flow for the time periods Day|Evening|Night. CadnaA - Reference Manual 2 117 Chapter 2 - Sound Sources 2.4.4 NMPB-Routes 1996 The road gradient can be entered in % or be calculated automatically, depending on the z-heights of the road. Gradient (%) 2 For information on the different options offered in the list box „Road Gradient“ of the dialog Road see chapter 2.4.1 "Common Input Data", section "Road Gradient (%)", for details. There is no global correction available in NMPB-96 to correct for multiple reflections. However, CadnaA enables to restrict the calculation using image sources to the 1st order of reflection and to correct for multiple reflections according to RLS-90 /17/. see chapter 6.2.10.3 "NMPB-Routes 1996" and chapter 2.4.2 "RLS-90" CadnaA - Reference Manual Correction for Multiple Reflections 118 2 Chapter 2 - Sound Sources 2.4.4 NMPB-Routes 1996 2 CadnaA - Reference Manual Chapter 2 - Sound Sources 2.4.5 NMPB-Routes 2008 2.4.5 2 119 NMPB-Routes 2008 The emission parameter in NMPB-2008 /78/ is the A-weighted third-octave sound power level per unit length and per vehicle in dB(A). This level calculates from /79/: LW / m j 10 lg 10 LW / m / VL 10 lg QVL /10 10 LW / m / PL 10 lg QPL /10 R j where LW/m/VL: sound power level per unit length of the light vehicles, in dB(A) QVL: hourly traffic of the light vehicles (max. mass m < 3500 kg), in veh/h LW/m/PL: sound power level per unit length of the heavy vehicles, in dB(A) QPL: hourly traffic of the heavy vehicles (max. mass m >= 3500 kg), in veh/h R(j): third-octave values of the reference spectrum for road noise, in dB(A) j: running number of octave In CadnaA, the overall traffic flow Q (in vehicles/hour) and the percentage of heavy vehicles p% is to be specified instead. The relation between those figures and the ones above are: Q QVL QPL and p% QPL Q Dialog Road (for NMPB 2008) CadnaA - Reference Manual Emission Parameter 2 120 2 Emission Parameter LwA’ 2 Chapter 2 - Sound Sources 2.4.5 NMPB-Routes 2008 The emission parameter displayed on the dialog Road is the A-weighted total sound power level per unit length L’Aw in dB(A) according to: 18 L'wA j 10 lg 100.1LW / m j in dB(A) j 1 In this case, always the emission spectrum for non-porous surfaces is used. Traffic Data The noise emission is calculated from traffic data based on the daily periods Day (6-18 h) and Night (22-6 h). The day may be subdivided into two further periods: 6-18 h (Day) and 18-22 h (Evening). The emission is estimated according the following specifications depending on: • • • the „Mean Daily Traffic Density“ (MDTD, veh/24h) or „Annual Average Daily Traffic“ (AADT, veh/24h) or the „trafics moyens journaliers annuels“ (TMJA, veh/24 h), the daily time period, the number of lanes (for urban and inter-urban roads). In any case, the emission is limited to the emission caused by a so-called „maximum traffic flow“ situation („émission sonore maximale du flot“). MDTD (TMJA) Specifying the MDTD or TMJA calculates the emission level depending on the road type selected. NMPB 2008, table 2.1, specifies TMJA-ranges in combination with ranges of the percentage of heavy vehicles %PL: Road Type Voiries structurantes urbaines Voiries urbaines intersecteurs Voiries urbaines de secteurs TMJA %PL %HPS veh/day daytime (6-22 h) nighttime (22-6 h) 17000 to 217000 5 to 20% 5 to 35% 2500 to 25000 (Île-deFrance: 50000) 0 to 5% %TV daytime 7,5 to 9,5 6,5 to 9,5 %TV nighttime - 85 to 95% 15 to 5% CadnaA - Reference Manual 2 121 Chapter 2 - Sound Sources 2.4.5 NMPB-Routes 2008 The following road types are available: • • Road Types road types from the German VBUS /115/ are taken instead in CadnaA (see chapter 2.4.2 "RLS-90", section "MDTD - VBUS"), and road types from NMPB 2008 /79/: Average hourly Flow Rate per Daily Period (veh/h) Road Type 6 - 18 h 18 - 22 h 22 - 6 h Motorway long distance TMJA/17 TMJA/19 TMJA/82 Motorway regional TMJA/17 TMJA/18 TMJA/100 Intercity long distance TMJA/17 TMJA/19 TMJA/110 TMJA/17 TMJA/19 TMJA/120 Intercity regional Average hourly Flow Rate for PL (HGV) per Daily Period (veh/h) Road Type 6 - 18 h 18 - 22 h 22 - 6 h Motorway long distance TMJA/20 TMJA/20 TMJA/39 Motorway regional TMJA/17 TMJA/28 TMJA/50 Intercity long distance TMJA/17 TMJA/27 TMJA/51 Intercity regional TMJA/17 TMJA/34 TMJA/73 This results in the following total number of vehicles per hour Q and percentage of heavy vehicles p%: total number of vehicles per hour Q per Daily Period (veh/h) *) Road Type 6 - 18 h 18 - 22 h 22 - 6 h Motorway long distance 0.109 TMJA 0.103 TMJA 0.038 TMJA Motorway regional 0.118 TMJA 0.091 TMJA 0.030 TMJA Intercity long distance 0.118 TMJA 0.090 TMJA 0.029 TMJA Intercity regional 0.121 TMJA 0.082 TMJA 0.022 TMJA percentage of heavy vehicles p% per Daily Period Road Type 6 - 18 h 18 - 22 h 22 - 6 h Motorway long distance 45.9 48.7 67.8 Motorway regional 50.0 39.1 66.7 Intercity long distance 50.0 41.3 68.3 Intercity regional 51.5 35.8 62.2 *) Factors rounded to third decimal, while CadnaA is using full precision. CadnaA - Reference Manual 2 122 2 Chapter 2 - Sound Sources 2.4.5 NMPB-Routes 2008 The maximum speed is 130 km/h for autos, and 100 km/h for trucks. Speed Correction NMPB 2008 states that the speed of autos is equivalent to the indicated maximum speed of a road while the maximum speed of trucks are depending on road type. In CadnaA, however, the speed of trucks has to edited by the user as these road types do not combine with the road types used for MDTD/ TMJA. 2 Road Type Speed of Trucks PL (km/h) highway interconnection 90 speed lane, urban 90 road with separated carriage ways 85 road with single carriage ways 80 in agglomerations indicated speed The values R(j) of the weighting spectrum are listed in the following table: Reference Spectrum third-octave band center frequency (Hz) 100 125 160 200 250 315 400 500 630 porous surfaces -22 -22 -20 -17 -15 -12 -10 -8 -9 non-porous surfaces -27 -26 -24 -21 -19 -16 -14 -11 -11 third-octave band center frequency (Hz) 800 1000 1250 1600 2000 2500 3150 4000 5000 porous surfaces -9 -10 -11 -12 -13 -16 -18 -20 -23 non-porous surfaces -8 -7 -8 -10 -13 -16 -18 -21 -23 Source Description For each vehicle category, the emission (sound power level per unit length) consists of two components: LW / m / veh 10 lg 10 0.1Lr_ W / m 0.1 Lm_ W / m 10 where Lr_W/m: rolling noise, due to tire-road interaction, called „roll noise“ Lm_W/m: mechanical sources of the vehicles, called „engine noise“ CadnaA - Reference Manual 2 123 Chapter 2 - Sound Sources 2.4.5 NMPB-Routes 2008 The roll noise component for three types of road surface (R1, R2, R3) is given in the next table („average emission for an aged surface less than ten years old“): Attribute Value STRONR Road Surface Category Speed Range v (km/h) Autos (VL) Speed Range v (km/h) Trucks (PL) LWA’ (dBA/m) (20 <= v <= 130) LWA’ (dBA/m) (20 <= v <= 100) 1 Revêtement R1 53,4 + 21 log (v/90) 61,5 + 20 log (v/80) 2 Revêtement R2 55,4 + 20,1 log (v/90) 63,4 + 20 log (v/80) 3 Revêtement R3 57,5 + 21,4 log (v/90) 64,2 + 20 log (v/80) 4 Revêtement R1 drainant as for Revêtement R1 as for Revêtement R1 5 Revêtement R2 drainant as for Revêtement R2 as for Revêtement R2 6 Revêtement R3 drainant as for Revêtement R3 as for Revêtement R3 Regarding the roll noise component the following comments apply: • Porous and non-porous surfaces have the same speed correction, however, a different spectrum is used (see section "Reference Spectrum"). • By the three surface categories R1 to R3 several road surface types are grouped. For examples see NMPB-2008, section 2.7.2.1. • The road surface categories „Revêtement R2 drainant“ and „Revêtement R3 drainant“ are not listed in NMPB 2008, but have been introduced in CadnaA based on French user requests. CadnaA - Reference Manual Roll Noise 2 124 2 Age of Road Surface Chapter 2 - Sound Sources 2.4.5 NMPB-Routes 2008 NMPB-2008 corrects for the deterioration of the road surface with time as specified by the table below (with a: age of road surface in years): 2 Road Surface Category VL (light vehicles) PL (heavy goods vehicles) <= 2 years 2 to 10 years <= 2 years 2 to 10 years -4 0.5*(a - 10) -2.4 0.3*(a - 10) R2 -2 0.25*(a - 10) -1.2 0.15*(a - 10) R3 -1.6 0.2*(a - 10) -1 0.12*(a - 10) R1 The „Year of Construction of Surface“ is specified on each dialog Road while the „Year of Calculation“ is specified on the dialog Configuration, „Road“ tab, with NMPB-2008 selected (see chapter 6.2.10.4 "NMPB-Routes 2008"). Engine Noise Since the road surface definition in NMPB 2008 applies different speed corrections for Autos and Trucks, combined with an even more complex scheme for aging, it is not possible - in opposite to NMPB 1996 (see chapter 2.4.4) - to enter user-defined road surfaces in CadnaA. With engine noise the following effects influence the radiated noise: • • traffic flow condition, five different situations apply: stabilisée, accélération, décélération, troncons de démarrage, troncons d'arrêt. road gradient, three different situations apply: horizontal (gradient <= 2% absolute), increasing (gradient 2 to 6%), decreasing (gradient -2 to -6%) Gradients larger to 6% (absolute) do not increase the correction. For the time being, the respective equations for all engine noise situations are not stated here. CadnaA - Reference Manual 2 125 Chapter 2 - Sound Sources 2.4.5 NMPB-Routes 2008 The height entered in the dialog Geometry is the height of the road’s surface. The source height is 0.05 m above the road’s center line or above of the center lines of the outer lanes. Source Geometry The selected type of traffic flow applies to all daily periods D/E/N. Available types are: Traffic Flow • • • • • 2 stabilisée accélération décélération troncons de démarrage troncons d'arrêt Clicking this button enables to define different types of traffic flow for the time periods Day|Evening|Night. Button DEN There is no global correction available in NMPB-2008 to correct for multiple reflections. However, CadnaA enables to restrict the calculation using image sources to the 1st order of reflection and to correct for multiple reflections according to RLS-90 /17/. Correction for Multiple Reflections see chapter 6.2.10.4 "NMPB-Routes 2008" and chapter 2.4.2 "RLS-90" CadnaA - Reference Manual 126 2 Chapter 2 - Sound Sources 2.4.5 NMPB-Routes 2008 2 CadnaA - Reference Manual Chapter 2 - Sound Sources 2.4.6 CNOSSOS-EU (Road) 2.4.6 2 127 CNOSSOS-EU (Road) The emission parameter in CNOSSOS-EU /16/ is the A-weighted longterm average sound pressure level for Day, Evening and Night period, computed by summation over all frequencies: L Aeq,LT 10 lg 10 Le q ,T ,i Ai i 1 dB A where Ai: A-weighting correction according to IEC 61672-1 i: frequency band index (octaves 125 to 4000 Hz) T: time period corresponding to Day, Evening or Night Assuming a steady traffic flow of Qm vehicles of category m per hour is assumed, with an average speed vm (in km/h), the sound power per metre in frequency band i of the source line LW', eq,line,i,m is defined by: Qm L W',e q,line,i,m L W,i ,m 10 lg 1000 vm where LW,i,m is the directional sound power of a single vehicle (re. 10-12 W/m) CadnaA - Reference Manual Emission Parameter 2 128 2 Vehicle Categories 2 Chapter 2 - Sound Sources 2.4.6 CNOSSOS-EU (Road) Traffic flow Qm is expressed as yearly average per hour, per time period (Day, Evening, Night), for the following vehicle categories: Category m Name Description 1 Light motor vehicles Passenger cars, delivery vans <= 3.5 tons, SUVs, MPVs including trailers and caravans 2 Medium heavy vehicles Medium heavy vehicles, delivery vans > 3.5 tons, buses, motorhomes, etc. with two axles and twin tyre mounting on rear axle 3 Heavy vehicles Heavy duty vehicles, touring cars, buses, with three or more axles 4a Powered twowheelers Two-, Three- and Four-wheel Mopeds 4b Motorcycles with and without sidecars, Tricycles and Quadricycles The following traffic amount formula and attributes apply to the respective input boxes on the Road dialog (see also section "Exact Counts"): Input Box Amount formula from categories m CadnaA Attributes Number of Vehicles/Hour 1+2+3+4 Percentage heavy vehicles 2+3 (%) (2+3)/(1+2+3+4)*100% Heavy Trucks 3 in 2+3 (%) 3/(2+3)*100% PLT, PLE, PLN Motorcycles 4a+4b (%) (4a+4b)/(1+2+3+4)*100% PSLAT, PSLAE, PSLAN Motorcycles 4b in 4a+4b (%) 4b/(4a+4b)*100% PLLAT, PLLAE, PLLAN MT, ME, MN PT, PE, PN CadnaA - Reference Manual 2 129 Chapter 2 - Sound Sources 2.4.6 CNOSSOS-EU (Road) The calculation of emission considers two main noise source types: • • Source Types rolling noise due to the tire-road interaction (while aerodynamic noise is incorporated in the rolling noise source). propulsion noise produced by the drive line (engine, exhaust, etc.) of the vehicle. 2 For light, medium and heavy motor vehicles (categories 1, 2 and 3), the total sound power corresponds to the energetic sum of the rolling and the propulsion noise. For two-wheelers (category 4), only propulsion noise is considered. For all categories, with speeds less than 20 km/h the sound power level as for vm=20 km/h is used. The emission by rolling noise is described by the sound power level in the frequency band i per vehicle of class m=1, 2 or 3: v L WR ,i,m AR ,i ,m BR,i, m lg m vref Rolling Noise LWR ,i ,m with L WR,i,m L WR ,road,i,m L studdded tyres,i,m L WR,acc ,i ,m L W,temp The coefficients AR,i,m and BR,i,m are given in octave bands for each vehicle category and for a reference speed vref = 70 km/h (see /16/ for details). LWR,i,m is the sum of the following corrections for rolling noise: Correction accounts for the effect on rolling noise ... frequency dependent LWR,road,i,m by road surfaces different from the virtual reference surface yes for details see below in this chapter Lstudded tyres,i,m by studded tyres with light vehicles (category 1) yes enter period and percentage on the „Road“ tab, see chapter 6.2.10.5 LWR,acc,i,m by crossings with traffic lights or roundabouts no for details see chapter 2.5 "Crossings with Traffic Lights" LW,temp by the temperature T different from Tref = 20°C yes see chapter 6.2.10.5 CadnaA - Reference Manual Remarks 130 2 Propulsion Noise 2 Chapter 2 - Sound Sources 2.4.6 CNOSSOS-EU (Road) The propulsion noise emission includes all contributions from engine, exhaust, gears, air intake, etc. The propulsion noise sound power level in the frequency band i for a vehicle of class m is: v vre f L WP ,i, m AP,i,m BP,i,m m vref L WP,i,m with L WP,i,m L WP ,road,i,m L WP,grad,i,m L WP,acc,i,m The coefficients AP,i,m and BP,i,m are given in octave bands for each vehicle category and for a reference speed vref = 70 km/h. LWP,i,m is the sum of the following corrections for propulsion noise: Correction accounts for the effect on propulsion noise ... frequency dependent Remarks LWP,road,i,m by different road surfaces due to sound absorption yes for details see below in this chapter LWP,grad,i,m by road gradients no for details see below in this chapter LWP,acc,i,m by accelerating and decelerating vehicles at intersections no for details see chapter 2.5 "Crossings with Traffic Lights" CadnaA - Reference Manual 2 131 Chapter 2 - Sound Sources 2.4.6 CNOSSOS-EU (Road) Specification of Emission The specification of traffic counts using MDTD („Mean Daily Traffic Density“, vehicles/24h) in conjunction with a road type does not exist in CNOSSOS-EU as an input parameter for traffic data. Nevertheless, this feature is available in CadnaA by applying the road types and traffic counts as specified by the Austrian road noise standards RVS 3.02 /59/ and RVS 4.02 /60/ respectively (see chapter 2.4.3, section "MDTD"). Counts, MDTD This option enables to enter counts and percentages for the five CNOSSOSspecific vehicle classes. Exact Counts Note that the „Number of Vehicles/hour“ addresses the total amount for all classes and the „Percentage heavy vehicles 2+3 (%)“ and the „Percentage Motorcycles 4a+4b (%)“ refer to that amount, whilst „Percentage Trucks 3 in 2+3 (%)“ and „Percentage Motorcycles 4b in 4a+4b (%)“ refer to the both above percentages being assumed as 100%. Example: Percentage Trucks 3 in 2+3 = 50%, for Day: 50% of 15% gives 7.5%, resulting in 7.5% vehicles in each of classes 2 and 3 Percentage Motorcycles 4a+4b =0%: no motorcycles in 4a and 4b The emission data for vehicle categories 1, 2, 3, 4a and 4b can be edited in the configuration (see chapter 6.2.10.5, section "Vehicle Classes"). direct input of L‘wA in dB(A) LwA‘ dB(A) see chapter 2.4.1 "Common Input Data", section "Diurnal Pattern" Diurnal Pattern CadnaA - Reference Manual 2 132 2 Source Geometry 2 Chapter 2 - Sound Sources 2.4.6 CNOSSOS-EU (Road) In CNOSSOS-EU, a road with multiple lanes can be replaced in the calculation alternatively: 1. by a number of source lines placed in the centre of each lane, or 2. by a single source line in the middle of a two way road, or 3. by one source line per carriageway in the outer lane of multi-lane roads. In CadnaA, alternative 3 is applied by default. In order to use alternative 1 enter as many parallel road objects as there are lanes, each road object having a road width of 0 m (causing a single emission line in each case). In order to apply alternative 2, deactivate the option „Calculate outer Lanes separately“ on the „Road“ tab (see chapter 6.2.10.5). The line source/s is/are segmented with each segment being replaced by a point source. The source height is 0.05 m above the road surface for all vehicle classes 1 to 4. The height entered in the dialog Geometry is the height of the road surface. Speed Correction Traffic speed can be specified for "Autos" and - if activated - for "Trucks" separately (in km/h). The speed limit entered for "Autos" will be considered for autos and motorcycles while the speed limit entered for "Trucks" - if any - will be considered for medium and heavy trucks. With the limit entered just for "Autos" (i.e. option "Trucks" deactivated) the value applies to all types of vehicles (i.e. no intrinsic speed limit for trucks). Consequently, there is no road-specific speed limit for motorcycles. However, a vehicle class specific speed limit for motorcycles can be entered on the „Road“ tab (see chapter 6.2.10.5). Button DEN see chapter 2.4.1, section "Button DEN" CadnaA - Reference Manual 2 133 Chapter 2 - Sound Sources 2.4.6 CNOSSOS-EU (Road) The effect of road gradient is considered in the propulsion noise only, where a steady speed is assumed. The correction term LWP,grad,m is a function of the slope s%, the vehicle speed vm (in km/h) and the vehicle class m. In the case of a bi-directional traffic flow, it is necessary to split the flow into two components and correct half for uphill and half for downhill. The same correction term is attributed to all octave bands. Road Gradient (%) 2 The equations used for gradient correction are not reproduced here. Instead, the subsequent diagrams show the range of the correction term LWP,grad,m depending on road gradient s% and on the vehicle‘s speed (in km/h) for vehicle categories m=1, 2 and 3. For vehicle category m=4 („powered twowheelers“) the correction LWP,grad,m=4 is zero at all speeds and gradients. When entering the road gradient manually the gradient correction is added to the emission value L‘WA. Road Gradient: Input (%) Note that, while the gradient correction itself is not frequency dependent, the resulting emission spectrum of the road segment will change anyway depending on the actual traffic mix due to different emission spectra per vehicle category. When using these options (see chapter 2.4.1, section "Road Gradient (%)") the gradient correction is not added to the emission value, but considered within the calculation. In this case, the gradient correction will be listed on the protocol (see chapter 6.5). CadnaA - Reference Manual Road Gradient: auto 134 2 2 Chapter 2 - Sound Sources 2.4.6 CNOSSOS-EU (Road) Vehicle Cat. 1: Light motor vehicles 20 18 ) 16 B (d 1 = 14 m , d ar g, 12 P W La tl e 10 D n o it c 8 e rr o c t n 6 e i d ar g 4 20 40 60 80 100 120 2 0 ‐20 ‐16 ‐12 ‐8 ‐4 0 4 8 12 16 20 gradient s% Vehicle Cat. 2: Medium heavy vehicles 20 18 16 ) B d ( 2 = ,m d ar ,g P LW at l e D n o it c re r o c t n ie ad rg 14 12 20 40 10 60 80 8 100 120 6 4 2 0 ‐20 ‐16 ‐12 ‐8 ‐4 0 4 8 12 16 20 gradient s% Vehicle Cat. 3: Heavy vehicles 20 18 ) 16 B d ( 3 = 14 ,m d ar ,g 12 P W La tl e 10 D n o it c 8 e rr co t n 6 ie d ar g 4 20 40 60 80 100 120 2 0 ‐20 ‐16 ‐12 ‐8 ‐4 0 4 8 12 16 20 gradient s% Correction for road gradient LWP,grad for vehicle categories m=1, 2, 3 and for speeds v = (20, 40, 60, 80, 100, 120) km/h CadnaA - Reference Manual 2 135 Chapter 2 - Sound Sources 2.4.6 CNOSSOS-EU (Road) This list box enables to select a road surface from the local or global library (). If records exist in the local library, they are displayed at the top of the list. Road Surface 2 gives access to the global library of road surfaces The road surface correction term for the rolling noise emission is: v L WR,road,i,m i,m m lg m dB v ref where i, m is the spectral correction in dB at reference speed vref for category m (1, 2 or 3) and spectral band i, m is the speed effect on the rolling noise reduction for category m (1, 2 or 3) and is identical for all frequency bands. The road surface correction term for the propulsion noise emission is: L WP,road,i,m min i,m ;0 dB This means that absorbing surfaces decrease the propulsion noise, while nonabsorbing surfaces do not increase it. The road surface correction for the „reference road surface“ (see below) is zero for all octaves and for all vehicle categories. CadnaA - Reference Manual Additional Information 136 2 Chapter 2 - Sound Sources 2.4.6 CNOSSOS-EU (Road) The following CNOSSOS-specific road surfaces are available: 2 Attribute Value STRO_ID Road Surface Description Validity Range *1) Min. speed [km/h] Max. speed [km/h] - - CNS_01 Reference road surface *2) CNS_02 1-layer ZOAB (very porous asphalt) 50 130 CNS_03 2-layer ZOAB 50 130 CNS_04 2-layer ZOAB (fine) 80 130 CNS_05 SMA-NL5 (stone mastic asphalt) 40 80 CNS_06 SMA-NL8 40 80 CNS_07 Brushed down concrete 70 120 CNS_08 Optimized brushed down concrete 70 80 CNS_09 Fine broomed concrete 70 120 CNS_10 Worked surface 50 130 CNS_11 Hard elements in herring-bone (e.g. made of prefabricated concrete or clay blocks) 30 60 CNS_12 Hard elements not in herring-bone 30 60 CNS_13 Quiet hard elements 30 60 CNS_14 Thin layer A 40 130 CNS_15 Thin layer B 40 130 *1) CNOSSOS-EU does not specify how to handle speeds lower the listed minimum speeds, but higher than the general lower speed limit of 20 km/h. In the same way, it does not specify how to handle speeds higher the listed maximum speeds. In CadnaA, therefore, the road surface corrections are applied irrespective of the speed for the time being. *2) „The reference road surface is considered to be a virtual road surface, consisting of an average of dense asphalt concrete 0/11 and stone mastic asphalt 0/11, between 2 and 7 years old and in a representative maintenance condition.“ (cited from CNOSSOS-EU) Further national road surfaces available in CadnaA will not get documented here. CadnaA - Reference Manual Chapter 2 - Sound Sources 2.4.7 CRTN 2.4.7 2 137 CRTN The evaluation parameter in CRTN („Calculation of Road Traffic Noise“) is the level L10 (for 18 hours) in dB(A) which is defined based on the level L10 hourly in dB(A) /81/. The level L10 (1h) is the level just exceeded in 10% of the time within one hour. The L10 (18h) is the arithmetic average of all values L10 (1h) between 6:00 and 24:00 hours (total 18 values). The emission parameter L10 is calculated from the following equations depending on what option for „Emission“ is selected: L10 (1h) 42.2 10 lg q or L10 (18h) 29.1 10 lg Q in dB(A) where the number of vehicles per hour q calculates from the 18h-count Q (see CRTN, charts 2 and 3): q 10 13.1 10 * Q or approximately q Q / 20.417 . This assumes a basic speed of v=75 km/h, a percentage of heavy vehicles (HGV) of p%=0, and a road gradient of G=0%. For the low traffic correction see chapter 6.2.10.6. Dialog Road (for CRTN) CadnaA - Reference Manual 2 Emission Parameter 138 2 Option „Motorway“ (marked by a red frame) 2 Chapter 2 - Sound Sources 2.4.7 CRTN This option is displayed only if „Leq acc. to Annex A Method 1 of TRL study“ is selected on the „Road“ tab (see chapter 6.2.10.6). Specification of Emission MDTD & Road Type The „Mean Daily Traffic Density“ (MDTD, vehicles/24h) does not exist in CRTN as an input parameter. Nevertheless, this feature is provided by CadnaA offering two options (see list box „Road Type“ on dialog Road): 1. Specification of the percentage of heavy goods vehicles (HGV, with an unladen mass > 1525 kg) in the range from 0% to 95%, applying the equation for q (as above). In this case, the resulting emission levels L10 are equal for all three daily time periods D/E/N. The attribute STRGATT enables to switch between different settings for the proportion of heavy vehicles by using the following string (where xx represents the proportion of heavy vehicles as a available from the list box „Road Type“): HGVxx (e.g. HGV50) 2. Specification of one of the road types from the German road noise standard RLS-90 /15/. The respective data for the hourly traffic data q (veh/h) and the truck proportion p(%) is given in the next table. In this case, the hourly count q for Day calculates from the 18h-count Q as specified by CRTN while for Night the distribution in RLS-90 is used. Thus, just the daytime level is in accordance with CRTN. Attribute Value STRGATTNR Road Type Day (6-22 h) Night (22-6 h) q (veh/h) p (%) q (veh/h) p (%) 0 Motorway q Q / 20.417 25 0.014 Q 45 1 Federal Road q Q / 20.417 20 0.011 Q 20 2 Ordinary Road q Q / 20.417 20 0.008 Q 10 3 Local Road q Q / 20.417 10 0.011 Q 3 CadnaA - Reference Manual 2 139 Chapter 2 - Sound Sources 2.4.7 CRTN This option enables to enter hourly traffic data q and percentage of heavy vehicles p% for the three time periods Day/Evening/Night. Exact Count Data 2 This data can also be imported via ODBC (see chapter 7.3). The emission level L10 can be entered directly. In this case, the corrections (for speed, road type etc.) are not applied. Specifying L10 Furthermore, diurnal patterns can be used in CadnaA to specify road emission. Diurnal patterns are introduced via the local libraries on the Tables menu. Diurnal Patterns Diurnal Pattern Subsequently, the ID of the pattern will be available from the lower end of the list box „Road Type“ on the dialog Road. As long as the option "Use Non Standard Reference Time D/E/N" on dialog Calculation|Configuration, tab „Road“, is deactivated the data from 6 to 24 hours of the selected pattern will be used to calculate the level L10 (i.e. ignoring the traffic figures from 0 to 6 hours). In this case, the figures displayed for the hourly traffic q are not correct as they refer to the entire pattern (from 0 to 24 hours). CadnaA - Reference Manual 140 2 2 Chapter 2 - Sound Sources 2.4.7 CRTN With counts Q being 0 (Zero) the pattern will be used as entered for calculation of emission. When entering a value for Qentered the hourly values qapplied of the pattern will be corrected according to: q applied Qentered (18h) * q pattern Q pattern , 6 24 h (18h) For the pattern above the result for L10,18h (displayed for D, while results for E and N not being relevant) will be the same when entering 18000 for Q results as with entering 0 (Zero). Entering the half amount (9000/18 h) will reduce the entire counts of the diurnal pattern to half of the values entered (see figures below). Example 1: road pattern „patt_01“ with 18000 veh./18 h selected, input of Q=0 considers the pattern as entered NOTE - Receiver levels may differ compared with input of Q=18000 since low traffic correction is applied with Q=0 by default (see chapter 6.2.10.6 "CRTN") Example 2: road pattern „patt_01“ with 18000 veh./18 h selected, input of Q=9000 considers half the amount of the pattern selected (i.e. 9000 veh./18 h) With the option "Use Non Standard Reference Time D/E/N" activated see chapter 6.2.10.6 "CRTN". CadnaA - Reference Manual 2 141 Chapter 2 - Sound Sources 2.4.7 CRTN According to CRTN, paragraph 4, the source of traffic noise (emitting line source) has to be taken 0.5 m above the road surface level and 3.5 m inwards from the nearside of the road’s edge (curb). This definition, however, refers to a situation with just receivers on one side of the road. In CadnaA, source lines are generated on either side of the road as the procedure should be applicable also to more complex scenarios with receivers on either side of the road or with grid calculations. CRTN-road with two emission lines (curb-to-curb distance 8 meters), radiation occurs just from the source line being closer to the receiver (option „Generate Rays“ activated on dialog Receiver) close-up: ray is extending from the near source line, source position is 3.5 meters inwards from the road’s curb CadnaA - Reference Manual Road & Source Geometry 2 142 2 Chapter 2 - Sound Sources 2.4.7 CRTN The distance from the source line to the curb has no influence on the emission of the road, i.e. just enabling to identify the location of the road's curb in relation to the source position. The default distance of 3.5 m is specified on the Options menu, Appearance (see chapter 2.4.1 "Common Input Data", section "Specification of Road Width"). 2 With receivers on either sides of the road both emission lines radiate. Radiation by a CRTN-road with two receivers on either side (curb-to-curb distance 8 meters) Additional Width With the self screening-option activated (see chapter 2.4.1, section "Dialog Geometry"), the actual road width can be specified by entering an additional width > 0 m for either side of a road. The additional width overrides the additional width defined on dialog Options|Appearance. In this case the source position referring to the road‘s center line is still the same, but the curb distance deviates from the default value of 3.5 m and, thus, the total road width. In conjunction with the option „Roads/Parking Lots are reflecting (G==0)“ activated (see chapter 6.2.7) this affects the resulting levels. As self-screening is not treated in CRTN at all, one could conclude to not apply the self-screening option when using CRTN in CadnaA. CadnaA - Reference Manual 2 143 Chapter 2 - Sound Sources 2.4.7 CRTN Example: For a road of a total width of 12 m curb-to-curb (input for „SCS/ Dist. (m)“ is „w12“) and with the additional widths 5 m left and 10 m right the new road width calculates from: Examples\ 02_Sources\ Road\ CRTN road width using add. width.cna source line distance: 12 - (2 x 3.5) = 5 m source from curb, left side: 5+1.75 = 6.75 m source from curb, right side: 10+1.75 = 11.75 m total width curb-to-curb: 5 + 6.75 + 11.75 = 23.5 m The following speed correction applies: Speed Correction 500 5p pV 33 lgV 40 10 lg1 68.8 dB( A) V V where V is the road type specific traffic speed (see table 6.1 in CRTN /81/, in km/h p is the percentage of heavy vehicles, calculated according to: p 100 f 100 F q Q f is the hourly flow of heavy vehicles F is the 18-hour flow of heavy vehicles Despite the limitation of chart 4 in CTRN, CadnaA applies this speed correction for any speed, also below 20 km/h and above 130 km/h. CadnaA - Reference Manual 2 144 2 Road Surface 2 Chapter 2 - Sound Sources 2.4.7 CRTN The following road surface types are available from the list box on dialog Road: Attribute Value STRONR road surface correction TD in dB at a speed of (with TD: texture depth in mm) Road Surface <= 75 km/h > 75 km/h 0 (manual input of attribute DSTRO) 1 (no correction) 0 2 Impervious, concrete -1 TD 10 lg90 TD 30 20 dB( A) 3 Impervious, bituminous -1 TD 10 lg20 TD 60 20 dB( A) 4 Pervious 0 - 3.5 -3.5 Default texture depth: 5.0 mm (attribute TEXDEP) Gradient (%) The road gradient can be edited manually by selecting "Input (%)" or be calculated automatically from the height points of the road polygon. This feature enables for a single road to calculate the gradient correction for each road section separately (for more details see chapter 2.4.1 "Common Input Data", section "Road Gradient (%)"). CadnaA applies the correction according to CRTN chart 6 for positive and negative gradients G: G 0.3 G dB ( A) with G gradient in % Furthermore, the traffic speed V on roads with gradients has to be reduced by V in accordance with CRTN, chart 5. This speed reduction is not accounted for by CadnaA automatically. Instead, always the entered speed is used for the speed correction. CadnaA - Reference Manual 2 145 Chapter 2 - Sound Sources 2.4.8 TNM 2.4.8 TNM Note - The Federal Highway Administration Traffic Noise Model (FHWA TNMTM) is protected by U.S. copyright laws. The noise prediction methodology used in CadnaA has been designed to be consistent with the FHWA TNMTM, however, CadnaA has not been tested, evaluated, or approved for use by any Agency of the U.S. Government. The emission parameter in TNM („Traffic Noise Model“) is the A-weighted level Ltraf,ref in dB(A) at a distance of 50 ft. (15.24 m) perpendicular to the axis of a road with infinite length with absorbing flat ground /89/. 2 Emission Parameter In TNM, emission is based on A-weighted levels (expressed in energy form), while sound level computations use one-third octave-band data, converted to A-weighted levels for display and output. Dialog Road (for TNM) The vehicle categories and their definitions available in TNM are listed in the subsequent table. For the time being, CadnaA does not allow for user-defined vehicle categories. CadnaA - Reference Manual Vehicle Categories 146 2 2 Emission Scheme Chapter 2 - Sound Sources 2.4.8 TNM TNM-vehicle categories Definition autos all passenger cars (2 axles, 4 tires), gross mass < 4500 kg (< 9900 lb) medium trucks cargo vehicles (2 axles, 6 tires), 4500 kg < gross mass < 12000 kg (9900 lb < m < 26400 lb) heavy trucks all cargo vehicles with 3 and more axles, gross mass > 12000 kg (> 26400 lb) buses all vehicles (2 or 3 axles) designated for transportation of 9 or more passengers motorcycles all vehicles with 2 or 3 tires with an open-air driver and/or passenger compartment The emission for each category, pavement type and throttle setting, is represented by 17 constants (2*7+3=17, resulting in 17*(5*4*2)= 680 constants in total) applying the following equations. The radiated energy EA is: E A ( si ) (0.6214 si ) A / 10 10 B / 10 10C / 10 , converted to A-weighted levels per third-octave band: 7 Lemis ,i ( si , f ) 10 lg E A X 1 0.6214 X 2 si lg f j 1 j 1 with X 1; X 2 D1; D2 , E1; E2 ,..., J1; J 2 where si A1...J1, A2...J2 f speed of vehicle type i (in km/h) constants (see table 5 in /90/) frequency (in Hz) Converted back to its energy form: Eemis (si , f ) 10 Lemis ,i / 10 CadnaA - Reference Manual 2 147 Chapter 2 - Sound Sources 2.4.8 TNM The emission level Ltraf,ref is not displayed in the TNM 2.5 software. Instead, the emitted energy E for each vehicle category can be exported to a csv-file using the procedure described in the box below. 2 Exporting spectra of energy parameter E from TNM 2.5 software: 1 - locate the file tnm.ini in C:\WINDOWS 2 - open the file and add the section: ... [Diagnostics] emission=1 ... 3 - with each TNM-calc run a file emit.csv is written besides the *.dat and *.idx files 4 - emit.csv lists the energy parameter E for each category and sub-source type 5 - sum E for all categories and sub-source types gives after conversion Ltraf,ref Specification of Emission CadnaA offers to introduce traffic data based on Mean Daily Traffic Data (MDTD), though not available in the original TNM. In this case, the number of vehicles per hour and the percentage trucks/buses is calculated according to the specifications in the Austrian road noise standards RVS 3.02 /59/ and RVS 4.02 /60/. For details (and tables) on the traffic count (veh/h) and proportion of heavy vehicles (%) for each type of road see chapter 2.4.3 "Nordic Prediction Method 1996", section "MDTD". In this case, the percentages of motorcycles and of heavy trucks and buses are, however, 0% for all road types as those vehicles types are not considered in the Austrian road noise standards RVS 3.02 and 4.02. CadnaA - Reference Manual MDTD 148 2 Exact Counts 2 Chapter 2 - Sound Sources 2.4.8 TNM This option enables to enter counts for the five TNM-specific vehicle types, comprising autos (cars), medium trucks, heavy trucks, buses, and motorcycles. As traffic data in TNM is specified in absolute figures for each vehicle type, while CadnaA uses - as the majority of road noise standards do - a scheme based on hourly overall traffic and percentage, the following transformations apply to convert absolute figures: Input data CadnaA Attributes calculates from TNM-input data according to ... number of vehicles/hour MT, ME, MN n Autos nMedium Trucks nHeavy Trucks nBuses nMotorcycles ntot Percentage of Trucks/Buses (%) PT, PE, PN n Percentage of Motorcycles (%) PLAT, PLAE, PLAN Percentage of heavy vehicles: Heavy Trucks (%) PLT, PLE, PLN nHeavy Trucks / nMedium Trucks nHeavy Trucks nBuses * 100% - Percentage of heavy vehicles: Buses (%) PLLAT, PLLAE, PLLAN nBuses / nMedium Trucks nHeavy Trucks nBuses * 100% Medium Trucks nHeavy Trucks nBuses / ntot * 100% nMotorcycles / ntot * 100% A scheme using hourly traffic and percentages has the advantage that overall traffic figures can be changed without altering the traffic mix. File Examples\02_Sources\Road\Road\Calc CadnaA-figures from TNM-figures.xls Ltraf,ref dB(A) direct input of Ltraf,ref in dB(A) Diurnal Pattern see chapter 2.4.1 "Common Input Data", section "Diurnal Pattern" Source Geometry Depending on vehicles type, sub-sources are located at different heights (at 0.1 m for tire, 1.5 m (5 feet) for engine, and 3.66 m (12 feet) for stack, all above ground). CadnaA - Reference Manual 2 149 Chapter 2 - Sound Sources 2.4.8 TNM A height of 0.1 m for the tire source as in TNM 2.5 software is used, while the TNM 1.0 documentation states a height of 0.0 m instead. Traffic speed can be specified for "Autos" and - if activated - for "Trucks" separately (in km/h). The speed limit entered for "Autos" will be considered as limit for autos and motorcycles, while the speed limit entered for "Trucks" - if any - will be considered for medium and heavy trucks, and for buses. With the limit entered just for "Autos" (i.e. "Trucks" deactivated) the value applies to all types of vehicles (no intrinsic speed limit for trucks). Speed Correction Accelerating ramps and flow control devices are not available in CadnaA for the time being. see chapter 2.4.1, section "Button DEN" Button DEN The following TNM-specific road surface types are available: Road Surface Attribute Value STRONR Road Surface Type 1 Average i.e. average of DGAC and PCC 2 DGAC dense-graded asphaltic concrete 3 OGAC open-graded asphaltic concrete 4 PCC Explanation Portland cement concrete FHWA states that the „average pavement type shall be used in the FHWA TNM for future noise level prediction unless a highway agency substantiates the use of a different pavement type for approval by the FHWA.“ The road gradient is not considered by CadnaA when calculating TNMspecific emission for the time being. Road Gradient (%) TNM has two kinds of operating conditions causing a different emission: „cruise throttle“ and „full throttle“. With the option „Throttle“ activated the respective road will be considered as a full throttle road. Throttle CadnaA - Reference Manual 2 150 2 Chapter 2 - Sound Sources 2.4.8 TNM 2 CadnaA - Reference Manual 2 151 Chapter 2 - Sound Sources 2.4.9 Czech Method 2.4.9 Czech Method The emission parameter according to the Czech Method is the A-weighted equivalent continuous sound pressure level LAeq,7.5m at a reference distance of 7.5 m from the center line of the outer lane of an infinite straight road with free sound propagation /95/. Emission Parameter The mean level LAeq,7.5m calculates from: Emission Level LAeq,7.5m LAeq , 7.5 m 10 lg X 10.1 in dB(A) with the correction X: X F1 F2 F3 where • • • the factor F1 expresses the influence of the speed of the traffic flow and the percentage of the lorries, the factor F2 expresses the influence of the road gradient (slope), and the factor F3 expresses the influence of the road pavement. Dialog Road (for Czech Method) CadnaA - Reference Manual 2 152 2 Chapter 2 - Sound Sources 2.4.9 Czech Method The factor F1 is calculated separately for daytime (6-22 h) and nighttime (622 h) according to: 2 F1 nOA FvOA 10 LOA / 10 nNA FvNA 10 L NA / 10 where nOA average traffic flow per hour of the cars (Day or Night) average traffic flow per hour of the lorries and buses (Day or Night) nNA FvOA speed dependence of the equivalent sound pressure level on the traffic flow consisting from the cars only (see below) LOA A-weighted sound pressure level of the passenger cars for the year under consideration, given in the table in section „Particular Years“ (see below) FvNA speed dependence of the equivalent sound pressure level on the traffic flow consisting from the lorries and buses only (see below) LNA A-weighted sound pressure level of the lorries and buses for the year under consideration, given in the table in section „Particular Years“ (see below) FvOA is given by: F 3.59 10 5 v 0.8 for v <= 60 km/h vOA FvOA 2.70 10 7 v 2 for v > 60 km/h 2 0.5 FvNA is given by: FvNA 1.50 10 v for v <= 60 km/h FvNA 2.45 10 4 v 0.5 for v > 60 km/h Particular Years Particular sound pressure level LOA (in dB) for cars, and LNA (in dB) for trucks and buses for years 1995-2005 are given in the next table. Year 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 level LOA cars, dB(A) 77.9 77.4 76.8 76.2 75.6 74.9 74.8 74.6 74.4 74.3 74.1 level LNA trucks and buses, dB(A) 85.4 84.7 84.0 83.3 82.4 81.4 81.1 80.9 80.7 80.4 80.2 CadnaA - Reference Manual 2 153 Chapter 2 - Sound Sources 2.4.9 Czech Method Specification of Emission Specifying the „Mean Daily Traffic Density“ (MDTD, veh/24h) calculates the emission level LAeq,7.5m depending on the road type based on the hourly traffic data M (veh/h) and the truck proportion p (%) according to the table below. Attribute Value STRGATTNR Road Type daytime (6-22 h) MDTD nighttime (22-6 h) M *1) (veh/h) p *2) (%) M *1) (veh/h) p *2) (%) 0 Motorway 0.0563 DTV (=0.9/16) 25 0.0125 DTV (=0.1/8) 12.5 1 Landscape mixed 0.0581 DTV (=0.93/16) 20 0.0087 DTV (=0.7/8) 10 2 Settlement mixed 0.06 DTV (=0.96/16) 20 0.005 DTV (=0.04/8) 10 3 Recreational 0.0606 DTV (=0.97/16) 10 0.0038 DTV (=0.03/8) 3 *1) M = nOA + nNA *2) p = nOA/(nOA + nNA) * 100% Any number of vehicles per hour M and other proportions of trucks p% can be specified when selecting this option. Exact Count Data for direct input of the emission level LAeq,7.5m see chapter 2.4.1 "Common Input Data", section "Diurnal Pattern" Diurnal Patterns The speed correction in CadnaA is based on the speed entered (whether it complies with an actual speed limit or not). Speed Limit (km/h) The height entered in the dialog Geometry is the height of the road’s surface. The source height is 0.5 m above the road’s center line or above the center lines of the outer lanes. Source Geometry CadnaA - Reference Manual 2 154 2 Road Gradient (%) Chapter 2 - Sound Sources 2.4.9 Czech Method The factor F2 expresses the influence of the slope s on the level LAeq,7.5m (see subsequent table). 2 One-way road Two-ways road Inclining Road Surface Declining % F2 % F2 % F2 1.00 s<1 1.00 s <= 6 1.0 s<1 1 <= s < 2 1.12 s>6 2.5 1 <= s < 2 1.06 2 <= s < 3 1.25 2 <= s < 3 1.13 3 <= s < 4 1.42 3 <= s < 4 1.21 4 <= s < 5 1.60 4 <= s < 5 1.30 5 <= s < 6 1.79 5 <= s < 6 1.40 s=6 2.00 s=6 1.50 s>6 2.50 s>6 2.50 The factor F3 expresses the influence of the road pavement on the level LAeq,7.5m. The correction for different road surfaces DStrO (in dB) can be entered or selected from the list box (for speeds > 50 km/h). By default, the road surfaces listed in a following table are available. For speeds < 50 km/h, the factor F3=1.0 for all types of asphalt concrete and concrete pavements. For the same speed range the factor is F3=2.0 for the small set pavings and F3 = 4.0 for the set pavings. CadnaA - Reference Manual Chapter 2 - Sound Sources 2.4.9 Czech Method Attribute Value STRONR Pavement Category 1 Aa Asphalt concrete - AC-8 Asphalt concrete continuously graded 1.0 2 Ab Gap-graded asphalt concrete for very thin layers ACVTL-11 (e.g. type RUMAC) 1.0 3 Ac Stone mastic asphalt SMA-11 or another asphalt with grading up to 11 mm (e.g. type ULM) 1.1 4 Ad Asphalt concrete AC-16HE with the use of modified bitumen 1.1 5 Ae Cold micro surfacing with grading up to 8 mm (e.g. type GRIPFIBRE) 1.2 6 Ba Concrete pavement with texture with towed jute 1.2 7 Bb Concrete pavement with negative transverse roughness 1.2 8 Bc Concrete pavement with fine transverse roughness 1.5 9 Ca Small set paving (surface course) 2.0 10 Cb Set paving (surface course) 4.0 Road Surface Factor F3 Multiple reflections within an urban road can be corrected for by the correction for multiple reflections according to RLS-90. This enables to reduce the order of refections considered by image sources (see chapter 6.2.8 "Reflection Tab"). see chapter 2.4.2 "RLS-90", section "Correction for Multiple Reflections" for details CadnaA - Reference Manual 2 155 2 Correction for Multiple Reflections 156 2 Chapter 2 - Sound Sources 2.4.9 Czech Method 2 CadnaA - Reference Manual Chapter 2 - Sound Sources 2.4.10 SonRoad 2.4.10 SonRoad According to the Swiss road noise model „SonRoad“ the A-weighted sound power level LwA in dB(A) emitted by the two vehicle types autos and trucks calculates from /94/: - for autos: v 3.5 0.1 60.5 10 lg 1 S 44 0.17.3 35 lg v BR LwA , autos 28.5 10 lg10 10 BG - for trucks: LwA , trucks 2 157 v 3.5 0.1 74.7 10 lg 1 S 56 0.116.3 35 lg v BR 28.5 10 lg10 10 BG where v: speed of autos or trucks, in km/h BR: correction for roll noise component on road surfaces (tabulated, see below), in dB(A) BG: correction for total noise component on road surfaces (tabulated, see below), in dB(A) S: gradient correction, in dB(A) Dialog Road (for SonRoad) CadnaA - Reference Manual Emission Parameter 2 158 2 Chapter 2 - Sound Sources 2.4.10 SonRoad In SonRoad, the emission is based on A-weighted sound power levels, while the calculation of propagation occurs in one-third octave-bands, in CadnaA converted to octave band levels and A-weighted levels. 2 The A-weighted sound power per unit length L’wA in third-octave bands results from: 23 N 0.1 L L 'wA 10 lg autos 10 j 0 v autos wA ,a utos Y j N trucks 0 .1L 10 vtrucks wA , tr ucks Y j 30 dB MK K1 where Nautos, Ntrucks: number of autos/trucks per hour vautos, vtrucks: speed of autos/trucks, in km/h Y(j): third-octave values of the reference spectrum (see below), in dB(A) j: running number of third-octave ML, K1: model & level corrections (see below) Reference Spectrum The values X(j) represent the A-weighting spectrum. As the emission data was measured on hard ground the final spectrum Y(j) results. j 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 Frequency (Hz) 100 125 160 200 250 315 400 500 630 800 1000 1250 1600 2000 2500 3150 4000 5000 X(j) in dB(A) -20 -20 -18 -16 -15 -14 -13 -12 -11 -9 -8 -9 -10 -11 -13 -15 -16 -18 Y(j) in dB(A) -24.3 -24.3 -22.3 -20.2 -19.1 -17.9 -16.6 -15.1 -13.4 -10.3 -7.6 -6.6 -7.5 -10.9 -14.5 -15.5 -15.1 -18.7 CadnaA - Reference Manual 2 159 Chapter 2 - Sound Sources 2.4.10 SonRoad Specification of Emission CadnaA offers to introduce traffic data based on Mean Daily Traffic Data (MDTD), though not available in SonRoad originally. In this case, the number of vehicles per hour N and the percentage trucks/buses eta (%) is calculated for the road type „Switzerland“ according to the specifications in the Swiss road noise standard STL-86 /64/. Road Type Switzerland Day (6-22 h) MDTD Night (22-6 h) N (veh/h) Eta (%) N (veh/h) Eta (%) 0.058 MDTD 10 0.009 MDTD 5 This option enables to enter the five hourly traffic figures N and percentage of heavy vehicles eta (%) for the time periods D/E/N. Exact Counts direct input of L’wA in dB(A) L’wA dB(A) see chapter 2.4.1 "Common Input Data", section "Diurnal Pattern" Diurnal Pattern The model correction MK can - as already available for STL86 /64/ - be entered for each road and time periods D/E/N individually. Model Correction MK The level correction K1 is a low traffic correction according to: Level Correction K1 5 : N 31.6 N K1 10 lg : 31.6 N 100 100 0 : N 100 where N: total number of vehicles per hour The speed correction in CadnaA is based on the speed entered (whether it complies with an actual speed limit or not). CadnaA - Reference Manual Speed (km/h) 2 160 2 2 Chapter 2 - Sound Sources 2.4.10 SonRoad Source Geometry The source height in SonRoad is 0.45 m above ground. Road Surface The table below lists the road surface corrections for the total noise (BG) and for the roll noise (BR). BG dB(A) Surface Type asphalt concrete AC 8,11,16 (also AB 10,11,16) 0 0 concrete (depending on age and condition) +2 0 porous asphalt PA 8,11 (formerly drain asphalt DRA 10,11) for speeds v > 70 km/h -4 0 mastic asphalt MA 8,11,16 (formerly GA) 0 0 rough asphalt AC MR 8,11 (formerly also Macro-Rugeux MR 6,11) -1 0 surface treatment OB 3/6 0 0 surface treatment OB 6/11 +1 0 stone mastic asphalt SMA 6 -1 0 stone mastic asphalt SMA 8,11 0 0 chipped mastic asphalt SPA 6,8,11 0 0 asphalt concrete TA 10 0 0 asphalt concrete TA 16 +1 0 0 +6 pavement (Note - Larger individual spread is likely.) Road Gradient (%) BR dB(A) A positive road gradient g (i.e. uphill) results in the level correction: S 0.8 g for g > 0% Roads with negative slope (i.e. downhill) receive no correction. Correction for Multiple Reflections Multiple reflections within an urban road can be corrected for by the correction for multiple reflections according to RLS-90. This enables to reduce the order of refections considered by image sources (see chapter 6.2.8 "Reflection Tab"). see chapter 2.4.2 "RLS-90", section "Correction for Multiple Reflections" for details CadnaA - Reference Manual Chapter 2 - Sound Sources 2.4.11 HJ 2.4 (2009) 2.4.11 HJ 2.4 (2009) The emission parameter according to the Chinese standard HJ 2.4 (2009) is the mean level Le,7.5m at 7.5 m distance from the road’s axis of an infinite straight road with free sound propagation /93/. For each of three vehicle types i it holds: L 2 161 L 10lg NV L e ,7.5m i i 0E i i slope,i L road surface 16 where (Le,7.5mE)i equivalent sound emission level of i-type vehicle per hour, in dB(A) energetic average of the A-weighted sound pressure level i for an i-type (L0E)i vehicle with speed Vi (km/h) at a horizontal distance of 7.5m, in dB(A) Ni average hourly traffic volume of i-type vehicle passing by, for daytime and nighttime, 1/h; Vi average speed of i-type vehicle, km/h gradient correction for i-type vehicle, dB Lslope,i road surface correction, dB Lroad surface Dialog Road (for HJ 2.4 - 2009) CadnaA - Reference Manual Emission Parameter 2 162 2 Emission Level L0E Chapter 2 - Sound Sources 2.4.11 HJ 2.4 (2009) The emission level depends on vehicle category i: i 2 vehicle class gross vehicle mass corresponding Chinese vehicle types (L0E)i dB(A) 1 small < 3500 kg M1, M2, N1 (L0E)i=1 = 12.6 + 34.73 log V1 2 medium 3500 12000 kg M2, M3, N2 (L0E)i=2 = 8.8 + 40.48 log V2 3 large > 12000 kg N3 (L0E)i=3 = 22.0 + 36.32 log V3 The equivalent sound pressure level of the total vehicle flow at 7.5 m distance from the road‘s axis results from: 3 Le,7.5m 10 lg 10 0.1Le ,7 ,5 m ,i i 1 MDTD The „Mean Daily Traffic Density“ (MDTD, vehicles/24h) does not exist in HJ 2.4 (2009) as an input parameter for traffic data. Nevertheless, this feature is provided by CadnaA applying the road types of the Austrian road noise standards RVS 3.02 /59/ and RVS 4.02 /60/. Regarding the traffic mix assumed depending on the selected road type see chapter 2.4.3 "Nordic Prediction Method 1996". Source Geometry The height entered in the dialog Geometry is the height of the road’s surface. By default, the source height is at the height of the road’s center line or above of the center lines of the outer lanes (default value: 0.0 m). CadnaA - Reference Manual 2 163 Chapter 2 - Sound Sources 2.4.11 HJ 2.4 (2009) The valid speed range for vehicle classes i=1..3 is: i vehicle class valid speed range 1 small 63 km/h to 140 km/h 2 medium 53 km/h to 100 km/h 3 large 48 km/h to 90 km/h Speed Range 2 Outside the mentioned speed range the sound power emitted by the point source/s resulting from segmentation of the road is constant using the respective lower or upper limit. Nevertheless, when entering speeds outside the valid speed range the displayed emission value of the road (here Le,7.5m) will change since the speed itself alters this value due to longer pass-by duration (at lower speeds) or shorter pass-by duration (at higher speeds). The correction for different road surfaces Lroad surface can be entered or selected from the list box providing the road surface types of HJ 2.4. The available road surfaces are listed in a following table. Attribute Value STRONR *) Lroad surface in dB Road Surface at a speed of 30 km/h 40 km/h >= 50 km/h 1 Bitumen concrete 0 0 0 2 Cement concrete 1.0 1.5 2.0 *) By the attribute value STRONR=0 the numerical input of DStrO is selected. CadnaA - Reference Manual Road Surface 164 2 Gradient (%) 2 Correction for Multiple Reflections Chapter 2 - Sound Sources 2.4.11 HJ 2.4 (2009) The road gradient g% can be entered or be calculated automatically, depending on the z-heights of the road. The list box „Road Gradient“ on the Road dialog the offers different options (see chapter 2.4.1, section "Road Gradient (%)"). Large Vehicles: Lslope 98 g% 100 Medium Vehicles: Lslope 73 g% 100 Small Vehicles: Lslope 50 g% 100 The reflection model in HJ 2.4 (2009) makes use of the correction for multiple reflections as specified in RLS-90 /17/. The correction for multiple reflections - called „Lreflection“ in HJ 2.4 (2009) - depends on the average height of the buildings left/right and on the distance among them. According to RLS-90 a correction for multiple reflections applies only when percentage of gaps between the buildings is less than 30%. Consequently, when applying this correction for multiple reflections the user has to ensure that just the first order of reflection is calculated by reflected rays. When the option „Calc exactly one reflection order“ on the „Road“ tab (Calculation|Configuration menu, see chapter 6.2.10.10) is activated, this occurs automatically. This holds also when a different order of reflection is specified on the „Reflection“ tab (see Chapter 6.3.9). A calculation without any reflections can be performed by deactivating the option „Calc exactly one reflection order“ and specifying no order of reflection (i.e. zero). CadnaA - Reference Manual 2 165 Chapter 2 - Sound Sources 2.4.11 HJ 2.4 (2009) This is the excess sound level due to multiple reflections. When this option is activated a correction (in dB) for multiple reflections can be entered. Drefl 2 Alternatively, the correction is calculated from the average height of the buildings on each side of the road, and the average distance (in m) between the buildings on both sides of the road according to: between reflecting buildings (percentage of gaps < 30%): Drefl 4 * hBeb / d Beb 3.2 dB between absorbing buildings: Drefl 2 * hBeb / d Beb 1.6 dB between highly absorbing buildings: Drefl 0 dB average height of the buildings (attribute HBEB) Average Height (m) average distance between the buildings (attribute ABST) Distance (m) absorption of the buildings (reflecting, absorbing or highly absorbing). Absorption According to RLS-90, the correction for multiple reflections - when specified - is applied independently from the receiver’s distance. In CadnaA, the correction for multiple reflections is considered in the road’s emission level (see calculation protocol). The command Calc Width of Roads (Extras menu) calculates the average height, the average distance and the proportion of gaps between buildings parallel to the roads. Calc Width of Roads For details see chapter 2.4.2 "RLS-90", section "Calc Width of Roads". Since HJ 2.4 (2009) applies the same correction scheme for traffic lights as RLS-90, the object „Crossing“ may be used in road noise models as well (see chapter 2.5 "Crossings with Traffic Lights"). CadnaA - Reference Manual Additional Information 166 2 Chapter 2 - Sound Sources 2.4.11 HJ 2.4 (2009) 2 CadnaA - Reference Manual Chapter 2 - Sound Sources 2.4.12 Further Procedures for Road Noise 2.4.12 2 167 Further Procedures for Road Noise Information on the following standards or guidelines for road noise can be found in the German version of the CadnaA-reference manual: • RVS 4.02, Austria • StL-86, Switzerland • DIN 18005 (1987), Germany CadnaA - Reference Manual 2 168 2 Chapter 2 - Sound Sources 2.4.12 Further Procedures for Road Noise 2 CadnaA - Reference Manual Chapter 2 - Sound Sources 2.4.13 Air Pollution according to MLus-92 2.4.13 Air Pollution according to MLus-92 CadnaA enables to calculate the impact by air pollutants caused by road traffic according to a national German procedure, called MLuS-92, edition 1996 /48/. The calculation of air pollution according to MLuS-92 in CadnaA assesses as with the simplified noise calculation in RLS-90 - a „Long Straight Road“ scenario. The calculation scheme opens by selecting the command Air Pollution from the road’s context menu. On the dialog, the relevant input parameters of this road are transferred from the Road dialog. Alternatively, open the dialog from the Extras|Air Pollution menu. In this case, the corresponding parameters such as traffic counts, truck percentage etc. must be entered manually. 2 169 For the time this dialog has not been translated to English. The unofficial translation of the terms used on the dialog is listed on the following page. CadnaA - Reference Manual 2 170 2 2 Chapter 2 - Sound Sources 2.4.13 Air Pollution according to MLus-92 German Term English Term DTV (Kfz /24 h) MDTD (cars/24 h) Lkw-Anteil (%) HGV% Pkw-Geschw (km/h) car speed Lkw-Geschw (km/h) truck speed Windgeschw (m/s) wind velocity Wind < 3 m /s (%) amount of wind situations in % with wind speed < 3 m/s Abstand Fb-Rand (m) distance from road curb Jahr (1985-2010) year of evaluation (range 1985-2010) Einheit/m³ unit/m³ for each component Vorbelastungstyp type of preload situation (open land, small/ medium/large town with small/medium/ high load) Prüfwert legal requirements (for Germany only), set to "user defined" Vorbelastung preload Zusatzbelastung additional load Gesamtbelastung total load Prüfwert limiting value Mittelwert mean value 98-Perzentil 98% statistical value As an alternative, the dialog can be opened via menu Extras|Air Pollution (MLUS). In this case, the relevant road parameters have to be entered via the keyboard. Values in red indicate an infringement or an incorrect entry. CadnaA - Reference Manual Chapter 2 - Sound Sources 2.5 Crossings with Traffic Lights 2.5 2 171 Crossings with Traffic Lights The majority of standards for road noise do not offer to model road crossings controlled by traffic lights. The only standards or procedures defining a correction are RLS-90 /17/, the Swiss „Guideline for Road Noise“ /67/ and CNOSSOS-EU /16/. The correction for road crossings controlled by traffic lights according to RLS-90 is applied for all road noise guidelines and standards implemented in CadnaA, besides • • • STL86+ /63//64/, SonRoad /70/ and CNOSSOS-EU /16/, provided that the object „Crossing w/ Traffic Light“ is used at all in the model. In RLS-90, the location of the object „Crossing“ in the model does not comply with its physical location, but is the imaginary intersection point of the respective emission lines (which is a hatched line, by default). This means that the traffic light‘s location according to RLS-90 does not correspond with the physical location of the traffic light, but represents the imaginary intersection of the corresponding emission lines (shown as a dashed line/s by default). In the model, the object „Crossing“ is located at the imaginary intersection point/s of the respective emission lines CadnaA - Reference Manual 2 Calculation according to RLS-90 172 2 Chapter 2 - Sound Sources 2.5 Crossings with Traffic Lights Options . Light is active When allocating a traffic light to a crossing or junction, the penalty according to RLS-90, section 4.2, table 2, is added to the receiver level automatically taking into account at what time, day, evening or night, the traffic light is active. 2 distance d of the receiver from the closest intersection of emission lines correction K (dB) <= 40 m 3 40 < d <= 70 m 2 70 < d <= 100 m 1 > 100 m 0 The correction K is applied only once (at multiple crossings with traffic lights). The check boxes enable to specify traffic light’s activity separately for daytime, evening and night-time. In the graphics, an active traffic light is indicated by a cross within the square. Crossing is Roundabout This option just applies to CNOSSOS-EU, see below. CadnaA - Reference Manual 2 173 Chapter 2 - Sound Sources 2.5 Crossings with Traffic Lights Any road lying within at a distance < 20 m to the traffic light’s position will be allocated to this crossing in the calculation, and will be listed on the list box „Associated Roads“. The option „Find Automatically“ is activated by default. Associated Roads, find automatically 2 To allocate a road to a crossing with traffic lights, enter at least a single active receiver and start the calculation by clicking the pocket calculator icon. In RLS-90 it is not explicitly specified how many and which roads in the vicinity of a traffic light receive the correction K. The procedure applied in CadnaA prevents from including other roads in the vicinity (e.g. a highway nearby). The automatic assignment is, therefore, a compromise not to apply the correction to too many roads. When selecting this option the respective roads can be assigned manually. Select via the button „Insert“ die name of the roads to be assigned from the table Road. Roads outside the search radius of 20 m require always have to be assigned manually in order to receive the correction. When roads nearby a traffic light are broken into pieces (e.g. with different speed limits) a manual assignment of all sections in the distance range 20 to 100 m is required. CadnaA - Reference Manual Associated Roads, assign manually 174 2 Chapter 2 - Sound Sources 2.5 Crossings with Traffic Lights Example 2 Road crossing with traffic lights: Grid showing the correction with limiting distances according to RLS-90 Calculation according to Swiss „Guideline for Road Noise“ The correction according to Swiss „Guideline for Road Noise, advice paper No. 0637“ /67/ is considered only if the road noise standards STL86+ or SonRoad are selected and the object „Crossing“ is used. distance d of the receiver from the closest intersection of emission lines correction (dB) < 25 m 2 25 <= d < 50 m 1 d >= 50 m 0 Furthermore, all remarks as given for RLS-90 hold, especially, with the option „Find Automatically“ being activated (default setting) the distance condition < 20 m to the traffic light’s position is used to decide whether a road is being listed in „Associated Roads“ or not. CadnaA - Reference Manual 2 175 Chapter 2 - Sound Sources 2.5 Crossings with Traffic Lights Again, the option „Crossing is Roundabout“ does not apply, see CNOSSOSEU below. Example Road crossing with traffic lights: Grid showing the correction with limiting distances according to the Swiss „Guideline for Road Noise“ In CNOSSOS-EU, the effect of the acceleration and deceleration of vehicles before and after crossings with traffic lights and at roundabouts is considered by correcting coefficients CR,m,k and CP,m,k depending on vehicle category and for crossings and roundabouts separately (for values see CNOSSOS-EU /16/). Both coefficients are not frequency dependent and are attributed to all octave bands equally. The correction terms for rolling noise, LWR,acc,m,k, and for propulsion noise, LWP,acc,m,k, are linear functions of the distance x (in m) of the point sources resulting from the segmentation of the road/s - to the nearest intersection of the respective source line with another source line: CadnaA - Reference Manual Calculation according to CNOSSOS-EU 2 176 2 Chapter 2 - Sound Sources 2.5 Crossings with Traffic Lights x L WR,acc,m,k CR ,m,k max 1 ;0 dB 100 2 x L WP,acc,m,k CP, m, k max 1 ;0 dB 100 The coefficients CR,m,k and CP,m,k depend on the kind of junction k (k = 1 for a crossing with traffic lights; k = 2 for a roundabout) and are given for each vehicle category. The correction includes the effect of change in speed when approaching or moving away from a crossing or a roundabout. Note that the correction becomes 0 dB at distances of 100 m and larger: x 100 m : L WR,acc, m,k LWP,acc, m,k 0 dB . Crossing is Roundabout Activate this option to mark a roundabout. In this case the corrections for k=2 are applied. In opposite to RLS-90 and SN 640 578, CNOSSOS-EU considers the correction for crossings with traffic lights and roundabouts on the source-side. This, however, may lead to different results depending on the raster factor applied (see chapter 6.2.3 "Partition Tab"). CadnaA - Reference Manual 2 177 Chapter 2 - Sound Sources 2.5 Crossings with Traffic Lights Example 2 Road crossing with a single traffic light according to CNOSSOS-EU: All rays extending from a source location at a maximum distance of 100 m from the traffic light receive a correction (red rays) while rays extending from more than 100 m distance do not receive the correction (gray rays). Note that the correction does NOT depend whether the receiver or grid point is situated closer than 100 m distance from the traffic light‘s location or not. CadnaA - Reference Manual 178 2 Chapter 2 - Sound Sources 2.5 Crossings with Traffic Lights 2 CadnaA - Reference Manual Chapter 2 - Sound Sources 2.6 Railways 2.6 2 179 Railways The sound source „Railway“ is radiating to all sides unless the option „SelfScreening“ is not activated (see chapter 2.4.1 "Common Input Data", section "Self-Screening"). The railway object may have different heights at each polygon point (see chapter 4.2). The source is located at the top edge of the rail (railhead) with a relative height of 0.6 m by default. Radiation from sound source „Railway“, relative height 0.6 m Radiation from sound source „Railway“, relative height 10.6 m, option „Self-Screening“ deactivated CadnaA - Reference Manual Radiation from sound source „Railway“, relative height 10.6 m, option „Self-Screening“ activated, additional width L/R 2 m each 2 180 2 2 Chapter 2 - Sound Sources 2.6 Railways The command Parallel Object (see manual „Introduction to CadnaA“) on the context menu of a railway enables to generate barriers, embankments, or contour lines at a specified distance or to generate station marks into the direction of the road using the command Generate Station (see manual „Introduction to CadnaA“). The parameters of a railway are entered in edit mode on the dialog Railway that opens when double-clicking on the railway’s center line. The subsequent chapters are specific for each standard or guideline available in CadnaA. These specifications do not represent a copy of the standardized procedures, rather the way they are implemented. CadnaA - Reference Manual 2 181 Chapter 2 - Sound Sources 2.6.1 Common Input Data 2.6.1 Common Input Data The dialog Railway offers two display modes, depending on whether the selected calculation standard uses an A-weighted emission parameter or emission spectra. Note the subsequent remark regarding the validity of the specification of emission with standards using different sub-sources (see section "Emission Parameter"). Dialog Railway with A-weighted emission parameter (Schall 03 - 1990) Dialog Railway with spectral emission (Schall 03 - 2014) CadnaA - Reference Manual Dialog Railway 2 182 2 Chapter 2 - Sound Sources 2.6.1 Common Input Data Emission Emission Parameter 2 When the option „Emission“ is selected, values for the standard-specific emission parameter can be entered for the daily periods Day/Evening/Night (D/E/N). Whether all three periods are relevant for the calculation depends on the selected railway standard and/or on the option „Use Non-Standard Reference Time D/E/N“ on the „Railway“ tab (see e.g. chapter 6.2.11.1). Train Classes and Penalties In case the selected calculation standard makes use of sub-sources at different source heights (with A-weighted or spectral emission), the specification of the emission is correct only when using the option „Train Classes and Penalties“ using the train classes specific to the standard. When toggling the option „Emission“ in this case, however, just a single source height will be used (see dialog Geometry of the „Railway“ object, usually 0.6 m above the railhead). With this option activated the number of trains for the guideline-specific train classes can be selected from a list (so-called „List of Trains“). In this case, CadnaA calculates the resulting emission level from the input data automatically (see guideline-specific chapters). In CadnaA, the emission spectrum is linear (unweighted), while the sum level is A-weighted („Tot-A“). There are two alternatives to define a list with number of trains: 1. By editing the local table on the dialog Railway. To this end, select the option „(local)“ from the list box. 2. By referencing an existing list with number of trains available from the Tables menu, Libraries (local)|Number of Trains. To this end, select the name of the train list from the list box. CadnaA - Reference Manual 2 183 Chapter 2 - Sound Sources 2.6.1 Common Input Data Number of Trains Use the context menu commands to insert new lines to the local train list. Editing a local list 2 Editing the local table is useful only when just a single railway section is concerned. In practice, a railway track has to be split into several sections due to changing parameters relevant for emission (such as track type or bridge penalty). With a local train list this would mean that with any small change (e.g. in the numbers of trains) each individual section would have to be reedited. To avoid this effort a list with number of trains is defined and referenced via the box „List of Trains“ for all relevant railway sections. Via the table Numbers of Trains (Tables menu, Libraries (local)) a table listing the number of trains for all railway classes travelling on a railway track can be compiled. To achieve this reference is established to the railway classes available from the local or global library (menus Tables|Libraries (global)| Railway Classes or Tables|Libraries (local)|Railway Classes). Subsequently, this list with number of trains is referenced on dialog Railway by selecting its name. This procedure has - compared with a local train list - the advantage that any changes in the table with the train numbers have to be edited once only, but will effect all railway section referencing that list, no matter whether the changes occurs via the table Railway (on the Tables|Sources menu) or via the list of trains in the edit dialog on dialog Railway. In either case, the change will be addressed to all railway sections referencing this list of trains. CadnaA - Reference Manual Library Number of Trains 184 2 Example Chapter 2 - Sound Sources 2.6.1 Common Input Data In the subsequent example, two railway sections are referencing to the local list with number of trains „1“. 2 Now, on dialog Railway of section 1 the number of trains for the first train class („ICE“) is changed from 30 to 50 trains. Upon closing the dialog by OK the change will be also become relevant to railway section 2 which is referencing this train list as well. CadnaA - Reference Manual 2 185 Chapter 2 - Sound Sources 2.6.1 Common Input Data 2 This change will also concern the train list „1“ in the local library. In case the change would have been made to that train list „1“ via the local library, all railway sections referencing this list would have been concerned by this change. The input boxes for each train class within the train list depends on the selected guideline for railway noise and will be explained in the following guideline-specific chapters. CadnaA - Reference Manual Edit Boxes for Railway Classes 186 2 Import Number of Trains 2 Chapter 2 - Sound Sources 2.6.1 Common Input Data Lists with Number of Trains can be imported and exported (File menu, command Import and. Export). see chapter 7.2.22 "Import / Export of Numbers of Trains" and regarding import operations: chapter 8.2 "Creating & Addressing Lists with „Number of Trains“" in the manual „Introduction to CadnaA“ (including an example) Purging Tables with Number of Trains When files containing train lists are imported, those train lists will be appended to the existing train lists. In order to prevent the list from increasing in length, select the command Purge Tables from the Tables menu to update this list with number of trains. Subsequently, all train lists not being referenced by any railway section will be deleted. CadnaA - Reference Manual 2 187 Chapter 2 - Sound Sources 2.6.1 Common Input Data Dialog Geometry The height entered in the dialog Geometry corresponds with the rail’s top edge (railhead). The default value is 0.6 m (relative height). Source Height When the option „Self-Screening“ on the dialog Geometry is activated the railway is just radiating into the upper half sphere. For the lower half sphere a screening effect occurs for all receivers below the railroad’s surface. This feature enables to define inclined railway lines, either upwards or downwards, by allocating the height above (relative) ground or an absolute height to every point of the railway, and by defining an additional width (e.g. considering sidewalks etc.). Since the option „Self-Screening“ is available, the use of the object „Bridge“ became superfluous (see chapter 3.3). Self-Screening With the self screening-option activated, the actual width of the railway line can be specified by entering an additional width > 0 m. The additional width can be defined separately for either side of a railway line. Additional Width left/ right 2 The graphical representation of the object „Railway“ (also on 3D Special View) does not consider the additional width (so, being different from the object „Road“). The specified additional width will, however, be considered upon calculation. The same holds in the same way for the additional parapets left/right. In addition, parapets (e.g. parallel barriers) for the self-screening road can be defined, either on one or both sides by entering a height left/right > 0 m. The parapets are treated as fully absorbing on either sides. This characteristic cannot be changed. Absorbing or reflecting barriers without or with cantilever can be defined just by using the object „Barrier“ (see chapter 3.2). The following requirements and properties are to be respected: • In any case, the additional width has to be > 0 m. • The parapets defined via option „Self-Screening“ are a characteristic of the railway and are not displayed in the 2D-graphics and not in the 3DSpecial view (see chapter 9.14) for the time being. • Barriers defined via option „Self-Screening“ will just screen the own source (railway), but not the noise from other kinds of sources. CadnaA - Reference Manual Parapet left/right 188 2 Stationing from/to 2 Chapter 2 - Sound Sources 2.6.1 Common Input Data This option enables to restrict the length of the barrier along the railway’s axis with reference to the stationing. In this case, the barrier is just generated for the range „from-up to“. This option is particularly useful when modeling bridges in order to suppress the diffraction around the edge of the railway sections at bridgeheads. For the automatic assignment two attributes are available: • • only for Ground Absorption, no Screening station start: SSCR_ST_B station end: SSCR_ST_E With this option being activated, the additional width entered will not cause any screening effect, but will just be considered when calculating ground absorption. This requires, however, that the respective option on the configurations is checked (dialog Calculation|Configuration, tab „Ground Absorption“, option „Roads/Parking Lots are reflecting G=0“, see chapter 6.2.7). With this option activated the speed of calculation may increase considerably due to the omission of barrier calculation. The self-screening effect of the road’s surface - including parallel barriers, if any - just refers to the respective road itself. Thus, the parallel barriers (parapets) defined via „Self-Screening“ are not seen by other sources. CadnaA - Reference Manual 2 189 Chapter 2 - Sound Sources 2.6.2 Schall 03 (1990) 2.6.2 Schall 03 (1990) 2 Dialog Railway (for Schall03-1990) The emission parameter according to Schall 03 (1990) is the mean level Lm,E at 25 m distance and at 3.5 m height above the rail’s top edge from the railway line’s axis with free sound propagation /23/. It calculates from (sum of all relevant train classes i): Lm , E 10 lg 100.1*51 DFz D D Dl Dv D Ae DFb DBr DBü DRa i where DFz: correction for the type of train DD: correction for the type of brakes Dl: correction for train length Dv: correction for the speed DAe: correction for aerodynamics DFb: correction for track type DBr: correction for bridges DBü: correction for level/grade crossings DRa: correction for curves The basic value of 51 dB(A) is the mean level at 25 m distance and at 3.5 m height above the rail’s top edge for a single train per hour with a length of 100 m, a speed of 100 km/h, and for 100% of the vehicles with disc brakes. CadnaA - Reference Manual Emission Level 190 2 Chapter 2 - Sound Sources 2.6.2 Schall 03 (1990) Type of Train Abbreviation 2 ICE EC IR D E N S SB SH SRR G GN U STR TR1 TR2 Type of Brakes Type of Train DFz (dB) InterCity Express EuroCity / InterCity Interregio passenger train local train commuter train S-Bahn (multiple unit) S-Bahn Berlin S-Bahn Hamburg S-Bahn Rhein-Ruhr Freight Train (distant) Freight Train (local) underground/subway tram Transrapid 07/1 Transrapid 07/2 -3 0 0 0 0 0 0 0 0 0 0 0 2 3 0 -1 DD = 10 lg (5 - 0.04 p) where p: percentage of vehicles with disc brakes referring to the train length (including locomotive/s) Train Length Dl = 10 lg (0.01 l) where l: sum of all trains of train class i per hour Speed Dv = 20 lg (0.01 v) where v: speed (track or loco max. speed) in km/h Aerodynamics DAe = 0 dB for v <= 250 km/h DAe = 1 dB for 250 km/h < v <= 300 km/h see /25/ CadnaA - Reference Manual 2 191 Chapter 2 - Sound Sources 2.6.2 Schall 03 (1990) Track Correction Attribute Value FBNR 1 2 3 4 Type of Track Lawn formation - Tramway Ballast - Wooden sleepers Ballast - Concrete sleepers Concrete Track - no absorption DFb (dB) -2 0 2 5 DBr = 3 dB Bridges In Schall 03, no distinction is made for different types of bridges. DBü = 5 dB 2 Level/Grade Crossings Schall 03 specifies that no additional track correction shall be used (DFb=0 dB) when applying the correction for level/grade crossings. Furthermore, the railway section length receiving this correction shall be twice the road width. Curves Radius of Curves r DRa (dB) r < 300 m 300 m <= r < 500 m r >= 500 m 8 3 0 The correction for curves DRa can be specified in conjunction with the correction for level/grade crossings DBü. With high-rise building structures lateral to the railway track a correction for multiple reflections can be considered based on the their distance and their mean height. For the calculation procedure of the correction see chapter 2.4.2 "RLS-90", section "Correction for Multiple Reflections". CadnaA - Reference Manual Correction for Multiple Reflections 192 2 Chapter 2 - Sound Sources 2.6.2 Schall 03 (1990) According to Schall 03 (1990) the correction for multiple reflections is just assigned to a receiver point when it is located „in the range“ of parallel buildings. Furthermore, Schall 03 does not contain provisions on how to apply the correction for curved railway tracks. In CadnaA, therefore, the procedure is applied to each section of the source’s polygon. It is checked whether the receiver point is located within half of the specified distance hBeb. If this is true, the correction for multiple reflections is applied, otherwise not. 2 Due to this strategy, it may occur that not all sections of the source are „seen“ from the receiver’s location (see calculation protocol). In order to reduce the number of sections the command Simplify Geo may be applied (see chapter 11.9 in the manual „Introduction to CadnaA“). vmax When specifying a track-relevant maximum speed vmax the train speed will be adjusted if necessary. In the calculation the smaller of both values is used. CadnaA - Reference Manual 2 193 Chapter 2 - Sound Sources 2.6.2 Schall 03 (1990) With this option activated, the types of trains and train classes, numbers of trains and corrections, can be edited locally, or an existing list with number of trains can be selected. CadnaA will automatically calculate the emission level from the specified values. Train Classes and Penalties 2 In the following, the procedure to edit a local train list (with numbers of trains) is described. To enter a train list in the local library, see chapter 2.6.1 "Common Input Data", section "Number of Trains". Local Train List The train type is selected from the list Train Types on the Library (global)|Railway Group (also called „Train Classes“). By this selection all relevant parameters, such as train length and speed or percentage of disc brakes, are specified. Train Type Numbers of trains for Day and Night (for Schall 03). In case the numbers are given by trains per hour, these values have to be multiplied by 16 to obtain the figure for Day and by 8 for Night. Number of Trains Day/ Evening/Night For calculations according to VBUSch /116/ the Evening period is relevant as well (D/E/N = 12/4/8 h). CadnaA - Reference Manual 194 2 2 Chapter 2 - Sound Sources 2.6.2 Schall 03 (1990) Speed relevant speed of trains of the respective train class (in km/h) Train Length length l of a train of the respective train class (in m) Type Correction By the type correction Dfz the effect of different kinds of vehicles is accounted for /23/ /24/. Alternatively, the train type is selectable from a list of train types. Type of Vehicle Vehicle w/ wheel-absorbers (401) Vehicle w/ disc brakes (403...) Vehicle w/ disc brakes (Bx) Subway Tram other Transrapid 07/1 - Magnetic Levitation Train Transrapid 07/2 - Magnetic Levitation Train DFz (dB) -3 -2 -1 2 3 0 0 -1 Emission Lm,E,i (dB) The emission level Lm,E,i for a train class resulting from the specified parameter is displayed here. Library with Number of Trains see chapter 2.6.1 "Common Input Data", section "Number of Trains" CadnaA - Reference Manual 2 195 Chapter 2 - Sound Sources 2.6.3 Schall 03 (2014) 2.6.3 Schall 03 (2014) NOTE - There is no official English version existing of the Schall03 (2014) calculation procedure. The following chapter provides an unofficial translation of terms and specifications. DataKustik refuses, therefore, any responsibility or liability for the final technical correctness of this translation. 2 Emission With this option activated, the types of locomotives, carriages, and cars or even entire trains („Train Composition“) can be specified using train classes, offering to enter corrections per train class or to select a list „Number of Trains“ (see chapter 2.6.1, section "Number of Trains"). CadnaA will automatically calculate the emission level from the entered values. Option „Train Classes and Penalties" Dialog Railway (option „Train Classes and Penalties“ selected) With this option selected, the linear (unweighted) emission level per octave band can be entered for the time periods D/E/N. In the box „Tot-A“ the Aweighted total level is displayed. Note that in this case just a unique source height can be used and that, consequently, the sub-sources (see section „Source Type m“) cannot be applied (see dialog Railway|Geometry, standard source height 0.6 m above ground level = railhead). CadnaA - Reference Manual Option „Emission Lw' “ 196 2 Emission Level 2 Chapter 2 - Sound Sources 2.6.3 Schall 03 (2014) The sound power level per unit length LW'A,f,h,m,Fz,l in octave band f, at the height h, for the sub-source m, of a single vehicle unit Fz per hour, with the number sources nQ and at a speed vFz calculates according to /26/: L W',f ,h,m,Fz ,l a A ,h,m,Fz a f ,h,m,Fz 10 lg with nQ v dB bf ,h,m lg Fz dB c1f,h ,m,c c2f ,h,m,c Kk nQ ,0 v0 c k aA,h,m,Fz: A-weighted total level of the sound power per unit length at a reference speed of v0=100 km/h on ballasted track with sleepers and with average surface condition, accord. to supplement 1 and 2, in dB Daf,h,m,Fz: level difference in octave band f in dB nQ: number of sources of the actual vehicle unit nQ,0: reference number of sources of the actual vehicle unit bf,h,m: speed factor v0: reference speed (=100 km/h) (c1f,h,m+c2f,h,m): sum of corrections for type of track and track surface in dB K: sum of corrections for bridges and prominence of noise types in dB The sound power level per unit length in octave band f and at height h by nFz vehicle units per hour calculates from: L W'A,f ,h 10lg n Fz100,1 LW ',f ,h ,m, Fz ,l dB m,Fz The calculation of the noise emission from marshaling yards is available in CadnaA by selecting the standard „Schall 03 (2014)“ from the list of industrial standards (see chapter 2.1.11). CadnaA - Reference Manual 2 197 Chapter 2 - Sound Sources 2.6.3 Schall 03 (2014) • Trains (see Table 3 in /26/): Vehicle Type High Speed EMU Locomotive High Speed EMU Car, not powered High Speed EMU train High Speed EMU, train tilting Electric Multiple Train and Electric Commuter Train, type „S-Bahn“ (ET) Diesel Multiple Unit (VT) Locomotive, Electric („E-Lok“) Locomotive, Diesel („V-Lok“) Passenger Car Freight Car • Type of Vehicles Fz Category Fz Reference Number of Axles nAchs,0 Vehicle Length (m) 1 2 3 4 5 4 4 32 28 10 20 26 200 185 52 6 7 8 9 10 6 4 4 4 4 68 20 20 26 20 Train compositions according to Table 4 /26/ („Verkehrsdaten für Eisenbahnen“, „Traffic Data for Trains“) are available from the library of global train classes (see chapter 2.6.12, section "Application Schall03 (2014)"). Trams (see Table 12 in /26/): Vehicle Type Tram - Low-Floor Vehicle Tram - High-Floor Vehicle Subway/Underground Vehicle CadnaA - Reference Manual Category Fz Reference Number of Axles nAchs,0 21 22 23 8 8 8 2 198 2 Sub-Sources m Chapter 2 - Sound Sources 2.6.3 Schall 03 (2014) • for trains (see Table 3 in /26/): subsource m height hS above railhead Rolling Noise 1 0m rail roughness 2 0m wheel roughness 3 4m emission of the rolling noise due rail roughness, transmitted by structure-borne sound via the body of tank wagons 4 4m emission of the rolling noise due wheel roughness, transmitted by structure-borne sound via the body of tank wagons 5 5m pantograph 6 4m bottom of pantograph, grids at cooling and air conditioning devices in roof section 7 0m airflow around bogies 8 4m ventilators of cooling and air conditioning devices, suction opening in roof section 9 0m ventilators of cooling and air conditioning devices, suction & pressure openings from underfloor 10 4m exhaust system 11 0m engine, gearbox 2 Aerodynamic Noise Noise by Technical Devices Traction Noise • Origin of Noise, Component Source Type for trams (see Table 12 in /26/): Source Type subsource m height hS above railhead Rolling & Traction Noise 1 2 Noise by Technical Units Origin of Noise, Component vehicle category Fz 0m rail roughness 21, 22, 23 0m wheel roughness, engine, gearbox 3 0m power converters, compressor, air conditioning & ventilation devices 22, 23 4 4m power converters, compressor, air conditioning & ventilation devices 21 CadnaA - Reference Manual 2 199 Chapter 2 - Sound Sources 2.6.3 Schall 03 (2014) • for trains (reference speed v0=100 km/h, see Table 6 /26/: Speed Factor b speed factor b at octave band center frequency (Hz) • Source Type Sub-Source m 63 125 250 500 1000 2000 4000 8000 rolling noise 1, 2, 3, 4 -5 -5 -5 0 10 25 25 25 aerodynamic noise 5, 6, 7 50 noise by technical devices 8, 9 -10 traction noise 10, 11 20 2 for trams (reference speed v0=100 km/h, see Table 14 /26/: speed factor b at octave band center frequency (Hz) Source Type SubSource m 63 125 250 500 1000 2000 4000 8000 Rolling & Traction Noise by Low- and HighFloor Vehicles 1, 2 0 0 -5 5 20 15 15 20 Rolling & Traction Noise, Subway/Underground Vehicles 1, 2 15 10 20 20 30 25 25 20 Noise by technical devices 3, 4 -10 When specifying a track-relevant maximum speed vmax the speed of trains/ trams will be adjusted if necessary. In the calculation the smaller of both values is used. CadnaA - Reference Manual Maximum Speed vmax 200 2 Chapter 2 - Sound Sources 2.6.3 Schall 03 (2014) • Type of Tracks 2 attribute value FBNR correction c1 for track types of trains (see table 7 /26/): parameter level corrections c1 in dB at octave band center frequency (Hz) 63 125 250 500 1000 2000 4000 8000 1 ballasted track on sleepers 0 0 0 0 0 0 0 0 2 slab track, not absorbing increased rail radiation 0 0 0 7 3 0 0 0 reflection from surface 1 1 1 1 1 1 1 1 increased rail radiation 0 0 0 7 3 0 0 0 reflection from surface 0 0 0 -2 -2 -3 0 0 increased rail roughness 0 0 0 8 4 0 0 0 3 4 slab track with absorber railroad crossing *) reflection 1 1 1 1 1 1 1 1 from surface *) The level correction for railway crossings is on cuts, corresponding to the 2-fold width of the road, to be set. Level correction for other types of roads are not taken into consideration. • correction c2 for track types of trains: The emission spectra of each train class applies to a track with sleepers (made of concrete, wood or steel) with ballast and with an average surface condition of the rail‘s surface without any specific acoustic measures at the rail. For the rail‘s surface condition „Special Surveillance (SpecSur)" (called „BüG“ in /26/) and for measures at the rails themselves the following corrections c2 apply (see table 8 /26/): track type subsrce m level corrections c2 in dB at octave band center frequency (Hz) 63 125 250 500 1000 2000 4000 8000 track with special surveillance (SpecSur) 1, 3 0 0 0 -4 -5- -5 -4 0 rail dampers 1, 3 0 0 0 -2 -3 -3 0 0 2, 4 0 0 0 -1 -3 -2 0 0 1 0 0 0 -3 -4 -5 0 0 rail dampers + special surveillance (SpecSur) 1, 3 0 0 0 -6 -8 -8 -4 0 2, 4 0 0 0 -5 -8 -7 -4 0 rail screening + special surveillance (SpecSur) 1 0 0 0 -7 -9 -10 -4 0 rail screening NOTE - Further provisions apply resulting from the footnotes of the tables for c1 and c2 /26/. CadnaA - Reference Manual 2 201 Chapter 2 - Sound Sources 2.6.3 Schall 03 (2014) • correction c1 for track types of trams (see table 15 /26/): attribute value FBNR track type subsrce m level corrections c in dB at octave band center frequency (Hz) 63 125 250 500 1000 2000 4000 8000 1 ballasted track on sleepers 1, 2 0 0 0 0 0 0 0 0 2 track bed on road surface level and slab track 1, 2 2 3 2 5 8 4 2 1 3 low level track bed, covered by lawn 1, 2 -2 -4 -3 -1 -1 -1 -1 -3 -4 -7 -7 -5 4 high level track 1, 2 1 -1 -3 -4 bed, covered by lawn NOTE - Further provisions apply resulting from the footnotes of the table /26/. Level Differences K CadnaA applies the correction for noise reduction measures NRM (called „KLM“ in /26/) within the bridge correction (see table 9 & 16 in /26/): attribute value DBRI 0 1 2 3 4 5 6 7 8 9 10 bridge type or superstructure type (no bridge) direct, steel superstructure direct, steel superstructure + NRM ballast, steel superstructure ballast, steel superstructure + NRM ballast, heavy plate ballast, heavy plate + NRM ballast, steel, noise reduced ballast, steel, noise reduced + NRM slab track grooved rail (tram) KBr + KLM (dB) 0 12 6 6 3 3 0 3 0 4 4 Schall03 (2014) specifies (see chapters 4.6 and 5.5 /26/) that this correction at trains and trams is a „combined correction for bridge and track type“ and that, in this case, no further correction for the track type shall be used. In CadnaA, therefore, changing the type of track does not cause any effect provided the option „(no bridge)“ is not selected. In this case, always „sleepers on ballasted track“ (default case) is assumed. CadnaA - Reference Manual Bridges 2 202 2 Curved Tracks Chapter 2 - Sound Sources 2.6.3 Schall 03 (2014) • 2 for trains (see table 11 /26/): Radius of Curvature r (m) KL + KLA (dB) < 300 300-500 >= 500 < 300 Kla 300-500 Kla 8 3 0 5 0 The level correction KLA („long-lasting provisions against squeaking“) is added. • Declining Sections for trams (see section 5.3.2 /26/): Radius of Curvature r (m) K (dB) < 200 >= 200 4 0 At declining sections with gradients >=2% and a minimum length of 500 m a penalty of 3 dB on the rolling noise at the height hs=0 m for freight trains with cast iron block brakes has to be considered due to braking noise. This specification in Schall03 (2014) requires that, if necessary, a separate railway object for freight trains with cast iron block brakes has to be entered in CadnaA to prevent from applying this correction also to other types of trains running on this section. Railway Correction If the so-called „Railway Correction“ (level difference Ks=-5 dB) has to be applied in order to account for the lower disturbing effect of railway noise, this has to be entered on the „Railway“ tab (see chapter 6.2.11.2). Marshaling Yards In order to evaluate of the noise emitted by marshaling yards the respective calculation model for industrial sources has to be selected in CadnaA (see chapter 2.1.11). CadnaA - Reference Manual 2 203 Chapter 2 - Sound Sources 2.6.3 Schall 03 (2014) In the following, the procedure to edit a local train list (with numbers of trains) is described. To enter a train list in the local library, see chapter 2.6.1 "Common Input Data", section "Number of Trains". Local Train List The train type is selected from the Library (global)|Railway Group via the list „Train Types“. Train Type Numbers of trains for Day and Night (for Schall03-2014). In case the numbers are given in trains per hour, these values have to be multiplied by 16 to obtain the figure for Day and by 6 for Night. Number of Trains Day/ Evening/Night relevant speed of the trains in a train class (in km/h) Speed v (km/h) Enter if necessary the number of axes night one. By default, the reference number of the respective axes of vehicle used. Number of Axles Here the sound power level per unit length LW',i in dB(A) resulting from the entered parameters for this train class is displayed. Emission LW', i (dB) CadnaA - Reference Manual 2 204 2 Chapter 2 - Sound Sources 2.6.3 Schall 03 (2014) 2 CadnaA - Reference Manual 2 205 Chapter 2 - Sound Sources 2.6.4 Nordic Prediction Method 1996 2.6.4 Nordic Prediction Method 1996 Two types of evaluation parameters are calculated according to Nordic Prediction Method (NPM) for railway noise (TemaNord 1996:524 /72/): • the A-weighted equivalent continuous sound pressure level LA,eq and • the A-weighted maximum sound pressure levels LmaxM (energy average over train length) or LmaxF (highest level with „Fast“ meter setting). Evaluation Parameters As the equivalent continuous level LA,eq is calculated per day (24 h) no specific day- or nighttime values exist. In contrary, a separate procedure is applied to calculate the maximum level LAFmax. Dialog Railway (for Nordic Prediction Method) The emission parameter for evaluations based on Leq is the linear (unweighted) sound power level per unit length L’wo /72/: v L'wo a lg 10 lgl24 h b Lc 100 where dB re 10-12 W a,b: constants depending on train type and frequency v: train speed, in km/h l24h: total passing train length within 24 hours, in m Lc: track correction, in dB CadnaA - Reference Manual Emission Level L’wo 2 206 2 Emission Level L’wt 2 Chapter 2 - Sound Sources 2.6.4 Nordic Prediction Method 1996 The emission parameter for maximum level evaluations is the linear (unweighted) sound power level per unit length L’wt /72/: v L'wt a lg 10 lg v 43.8 b Lc 100 where dB re 10-12 W a,b: constants depending on train type and frequency v: train speed, in km/h Lc: track correction, in dB Two types of levels are used to describe the maximum level of a train passage: the level LmaxM based on the energy average over train length, and the level LmaxF the highest level occurring at a passage with „Fast“ meter setting. For all frequency bands it holds: 3d Lmax F Lmax M 3 c 100 dB, for electric trains 3d Lmax F Lmax M 6 c 100 dB, for diesel trains with dc distance receiver - train centre (m) and the further conditions: dc > 100 m (electric trains): Lmax F Lmax M dc > 200 m (diesel trains): Lmax F Lmax M In CadnaA, both types of evaluation levels are available, see chapter 6.2.11.3 "Nordic Prediction Method (1996)" CadnaA - Reference Manual 2 207 Chapter 2 - Sound Sources 2.6.4 Nordic Prediction Method 1996 In case the option „Train Classes and Penalties“ is selected the track condition can be entered manually. The track correction Lc is also used to correct the emission level for joints, crossings, and bridges. Type of Track 2 Lc (dB) ballasted tracks with continuously welded rails on concrete or wooden sleepers rails with joints 10 m track length for each unit of switches and crossings partial track length on a bridge without ballast partial track length on a bridge with ballast Track Condition 0 3 6 6 3 CadnaA provides no list box for track conditions as NPM states ranges of the track correction, rather than distinct values. In particular, the track correction Lc at switches and crossings requires some additional modeling effort as the correction does not apply for the entire (and arbitrary) length of a railway section, but just to a finite length of 10 m. For both, LA,eq and LmaxM or LmaxF calculations, an additional railway section of 10 m length has to be entered at the location of each switch or crossing having the same emission as the neighboring railway sections, but with a track correction of Lc=6 dB. Further, the following rules regarding it‘s geometry apply: • with LA,eq calculations: The additional railway section representing a switch or a crossing replaces by its length the continuous railway track. In other words, the 10 m section cannot be drawn on top of the existing railway track as this would cause additional ray paths. Thus, a single railway segment needs to be broken into three peaces resulting in a single section of 10 m length in between two other sections (see chapter 11.10 in the manual „Introduction to CadnaA“). • with LmaxM or LmaxF calculations: In this case, the additional railway section representing a switch or crossing can be entered on top of the continuous railway track. Deactivate the option "Extrapolate trains to 1/2 length on both sides of rail" (see chapter 6.2.11.3). CadnaA - Reference Manual Application of the track correction Examples \02_Sources\Railway\ NPM 96\10 m switch correction.cna 208 2 Source Position 2 Chapter 2 - Sound Sources 2.6.4 Nordic Prediction Method 1996 The source heights with respect to the octave band centre frequency are listed on the following table (approximative): Partial Source Octave band centre frequency (Hz) 63 125 250 500 1000 2000 4000 2 1.5 0.8 0.3 0.4 0.5 0.6 Rails Wheels Engine etc. (Diesel power trains) Curve screech Carriages, wagon (primarily goods trains) Braking Source Position on the track centre line (meters above rail head) vmax (km/h) When specifying a track-relevant maximum speed vmax the train speed will be adjusted if necessary. In the calculation the smaller of both values is used. CadnaA - Reference Manual 2 209 Chapter 2 - Sound Sources 2.6.4 Nordic Prediction Method 1996 In CadnaA, the following train types are available from the global library (Tables menu, Libraries (global)|Railway Groups). Abbreviation Train Class Name Npas N-Pass El Ngoo N-Goods El Nb65 N-B65 Pass El Nb70 N-B70 Pass El Nb69 N-B69 Pass El Sx2 S-X2 Pass El Concr Spas S-Pass El Concr Spaw S-Pass/W El Wood Sx10 S-X10 Pass El Concr Sgod S-GoodsDi Diesel Concr Sgoo S-Goods El Concr Fsm F-Sm Pass El Concr Fsr1 F-Sr1 Pass El Concr Fgoo F-Goods mEl Wood Rgoo R-Goods mEl Concr B71t BM 71 El today maint B72t BM 72 El today maint B73t BM 73 El today maint B71i BM 71 El improved maint B72i BM 72 El improved maint B73i BM 73 El improved maint B93D BM 93 Di SL79 SL 79 Leddtrikk Tban T-bane T2k T-2000 X31 X31/32 Contessa X52 X52-53 Regina Y31 Y31 Itino In case those railway groups are not listed on the Tables menu, import the library „Train Classes“ from Type „Default“ into the global library. CadnaA - Reference Manual Train Types 2 210 2 Train Classes and Penalties 2 Chapter 2 - Sound Sources 2.6.4 Nordic Prediction Method 1996 With this option activated, the types of trains and train classes, numbers of trains and corrections, can be edited locally, or an existing list with number of trains can be selected. CadnaA will automatically calculate the emission level from the specified values. In the following, the procedure to edit a local train list (with numbers of trains) is described. To enter a train list in the local library, see chapter 2.6.1 "Common Input Data", section "Number of Trains". Local Train List Train Type The train type is selected from the list Train Types on the Library (global)|Railway Group (also called „Train Classes“). By this selection all relevant parameters are specified. Number of Trains Day/ Evening/Night Numbers of trains within 24 hours. With the same numbers of trains for time periods D/E/N the same power level L’wo,i D/E/N results (see also chapter 6.2.11.3). Speed v (km/h) relevant speed of trains (km/h) Length of one train (m) length l of the respective train class (m) Emission Lm,E,i (dB) The emission level (sound power per unit length) L’wo,i for a train class resulting from the specified parameter is displayed here. Library with Number of Trains see chapter 2.6.1 "Common Input Data", section "Number of Trains" CadnaA - Reference Manual Chapter 2 - Sound Sources 2.6.5 CRN 2.6.5 2 211 CRN The evaluation parameter in CRN („Calculation of Railway Noise“) is the level LAeq,18h in dB(A) /82/. 2 Dialog Railway (for CRN) The emission parameter is the A-weighted continuous sound pressure level LAeq,25m at a distance of 25 m from the nearside railhead. It calculates from the base line sound exposure level SEL in dB(A) at that distance: • for rolling railway vehicles (electric locos, cars and wagons): SEL vehicle 31.2 20lg v vehicle correction • in dB(A) for diesel locomotives (full power): SEL vehicle 112.6 10lg v vehicle correction in dB(A) where v: speed (km/h) vehicle correction: see subsequent section „Train Types & Type Corrections“ and for N number of identical vehicles: SELtot SELvehicle 10 lg N in dB(A) CadnaA - Reference Manual Emission Parameter 212 2 Chapter 2 - Sound Sources 2.6.5 CRN This results in the two levels LAeq for Day and Night: LAeq ,18 h SELtot 48.1 10 lg N day 2 in dB(A) LAeq , 6 h SELtot 43.3 10 lg N night in dB(A) where Track Condition Nday: number of trains during daytime (6 to 24 hours) Nnight: number of trains during daytime (0 to 6 hours) The numerical corrections result from the time correction for 18 hours (10 lg (18*3600s/1s) = 48.1 dB and 6 hours (10 lg (6*3600s/1s) = 43.3 dB. In case the option „Train Classes and Penalties“ is selected the track correction can be entered manually. Type of Track continuously welded rail - on concrete - on wooden sleepers jointed track, points and crossings slab track concrete bridges and viaducts steel bridges correction (dB) 0 0 +2.5 +2 +1 +(4 to 9) For the time being, CadnaA provides no list box for CRN-specific track corrections. CadnaA - Reference Manual 2 213 Chapter 2 - Sound Sources 2.6.5 CRN CRN specifies a ballast correction of -1.5 dB in case the sleepers are supported by an acoustically absorbing ballast layer (CRN, clause 22 /82/). In CadnaA the following specifications apply: • Option „Ballast“ 2 CadnaA applies the correction in the propagation, not in the emission (i.e. the emission value LAeq,25m is not changing with „Ballast“ on/off). • The correction applies to single and several parallel tracks as well. This means that the CRN-clause regarding the non-relevance of the ballast correction for single track railways is not considered automatically in CadnaA, but just in case the option is deactivated. • CadnaA does not apply the ballast correction for screened receivers (i.e. at least one or more barriers are intersecting the ray path). The CRN specification to not apply the ballast correction „for a locomotive on power“ (must read: „... on/under full power“) has to be ensured by the user by deactivating the option „Ballast“ in this case. With this option active the „correction for angle of view“ in CRN occurs according to chart 8 (in opposite to chart 7 for other types of trains /82/). CadnaA applies this correction in the emission value LAeq,25m. Option „Diesel locomotive full power“ Based on the track-relevant maximum speed vmax the train speed will be adjusted if necessary. In the calculation the smaller of both values is used. vmax (km/h) The source height in CRN is the height of the nearside railhead. The default height in CadnaA is 0.6 m relative above ground (see dialog Geometry). Geometry For diesel locomotives at full power, however, it is at 4 m above the nearside railhead. In CadnaA, with the option „Diesel locomotive full power“ activated, 4 m are automatically added to the height specified on dialog Geometry. CadnaA - Reference Manual 214 2 Train Types & Type Corrections 2 Chapter 2 - Sound Sources 2.6.5 CRN In CadnaA, the following types of train and type corrections are available. The data of the CRN-specific train classes is not available via the local or global libraries, but coded internally. Train Types CRN /82/ Abbr. Train Class Name Corr. dB(A) Abbr. Train Class Name Corr. dB(A) Mk1 British Rail MkI 14.8 C43 Class 43 18 Mk2 British Rail MkII 14.8 C47 Class 47 16.6 GwEx Gatwick Express 16.7 C56 Class 56 16.6 C421 Class 421 EMU 10.8 C59 Class 59 16.6 C422 Class 422 EMU 10.8 C60 Class 60 16.6 LUnA London Undergr-A Stock 12.9 C73 Class 73 14.8 LUnT London Undergr-Tube stock 7.1 C86 Class 86 14.8 Mk3 British Rail MkIII 6 C87 Class 87 14.8 Mk4 British Rail MkIV 6 C90 Class 90 14.8 C319 Class 319 EMU 11.3 C91 Class 91 14.8 C465 Class 465 EMU 8.4 C20F Class 20 Full Power C466 Class 466 EMU 8.4 C31F Class 31 Full Power 0 C165 Class 165 DMU 7 C33F Class 33 Full Power 0 C166 Class 166 DMU 7 C37F Class 37 Full Power 0 MML Manchester Metrolink LRV 15.8 C43F Class 43 (HST) Full Power 0 SYST South Yorkshire Supertram 14.9 C47F Class 47 Full Power 0 2XTW 2 axle tank wagon 12 C56F Class 56 Full Power 0 4XTW 4 axle tank wagon 15 C59F Class 59 Full Power 0 MGRC Merry Go Round Coal Hopper 8 C60F Class 60 Full Power 0 FL Freightliner 7.5 C390 Pendolino Brittanico 8.7 7.7 C20 Class 20 14.8 C220 Voyager C31 Class 31 16.6 C221 Voyager (tilting) C33 Class 33 14.8 C170 Turbostar C37 Class 37 16.6 0 6 7.6 CadnaA - Reference Manual 2 215 Chapter 2 - Sound Sources 2.6.5 CRN Train Types from DEFRAreport /86/ Abbr. Train Class Name Corr. dB(A) Abbr. Train Class Name Corr. dB(A) C168 168 Turbostar DMU 7.6 C450M 450 Desiro EMU (M) C170n 170 Turbostar DMU - new 7.6 C450T 450 Desiro EMU (T) 6 C175 175 Coradia DMU 7.6 C458M 458 Juniper EMU (M) 7.6 C180 180 Coradia DMU 7.6 C458T 458 Juniper EMU (T) C220n 220 Voyager DMU - new 7.6 C460M 460 Gatwick Juniper EMU (M) C221n 221 Voyager DMU - new 7.6 C460T 460 Gatwick Juniper EMU (T) 6 C323M 323 EMU (M) 8.7 KQA_l KQA loaded Pocket wagon 15 C323T 323 EMU (T) 6 C332M 332 Heathrow Express EMU (M) 8.7 6 7.6 KQA_e KQA empty Pocket wagon 17.5 7.6 C92 Class 92 locomotive Dual voltage electric 16.6 6 C332T 332 Heathrow Express EMU (T) BAA BAA wagon, Steel carrier, 4 axle 15.2 C333M 333 EMU (M) 7.6 BBA_l BBA wagon loaded, Steel carrier, 4 axle 13.4 C333T 333 EMU (T) 6 BBA_e BBA wagon empty, Steel carrier, 4 axle 16.1 C334M 334 Juniper EMU (M) 7.6 BDA_e BDA wagon empty, Bolster 4 axle 10.8 C334T 334 Juniper EMU (T) 6 BZA_l BZA wagon loaded, Steel carrier, 4 axle 11.8 C350M 350 Desiro EMU (M) 8.7 MEA_e MEA wagon empty, Box mineral, 2 axle 5.6 C350T 350 Desiro EMU (T) 6 TDA_l TDA wagon loaded, Tank, 4 axle 17.8 C357M 357 Electrostar EMU (M) 7.6 TEB_l TEB wagon loaded, Tank, 4 axle 20.2 C357T 357 Electrostar EMU (T) 6 TIA_l TIA wagon loaded, Tank, 2 axle 17.8 C375M 375 Electrostar EMU (M) 7.6 HTA_l HTA wagon loaded, Hopper, 4 axle 7.1 C375T 375 Electrostar EMU (T) 6 HTA_e HTA wagon empty, Hopper, 4 axle 10.4 C377M 377 Electrostar EMU (M) 7.6 C66 Class 66 rolling, Diesel locomotive C377T 377 Electrostar EMU (T) 6 C66F Class 66 on-power, Diesel locomotive C390Mn 390 Pendolino Britannico (M) new 7.6 C67 Class 67 rolling, Diesel locomotive C390Tn 390 Pendolino Britannico (T) new 6 C67F Class 67 on-power, Diesel locomotive C444M 444 Desiro EMU (M) 8.7 C444T 444 Desiro EMU (T) 6 CadnaA - Reference Manual 13 -13.4 7.4 -10.8 2 216 2 Train Classes and Penalties 2 Chapter 2 - Sound Sources 2.6.5 CRN With this option activated, the types of trains and train classes, numbers of trains and corrections, can be edited locally, or an existing list with number of trains can be selected. CadnaA will automatically calculate the emission level from the specified values. In the following, the procedure to edit a local train list (with numbers of trains) is described. To enter a train list in the local library, see chapter 2.6.1 "Common Input Data", section "Number of Trains". Local Train List Train Type The train type is selected from the list „Type“. By this selection all relevant parameters are specified. Number of Vehicles numbers of trains for Day/Evening/Night Speed v (km/h) relevant speed of trains (km/h) Type Correction (dB) type correction for this train type Emission LA25,i (dB) The emission level LA25,i for train class i resulting from the specified parameter is displayed here. Library with Number of Trains see chapter 2.6.1 "Common Input Data", section "Number of Trains" CadnaA - Reference Manual Chapter 2 - Sound Sources 2.6.6 SRM II 2.6.6 SRM II The calculation method SRM II is part of the „Recommended interim computation methods“ according to ANNEX II of the EC-Environmental Noise Directive /121/. The implementation of SRM II in CADNAA refers, therefore, primarily to the procedure described in the so-called EU-Interim Report /2/ and the EC-Recommendation L 212/49 /114/, and not to the original Dutch procedure /87/. The Dutch calculation method SRM II („Standaardrekenmethode 2“) calculates in octave band width and splits up the source into 2 or 4 subsources, located at different heights depending on the train category. Dialog Railway (for SRM II): spectrum is linear, sum-level is A-weighted („Tot-A“). Already within the calculation of emission, the portions of braking or not braking trains are distinguished. The emission level per unit length in octave band i is calculated by: Eh / 10 Eh / 10 LhE ,i 10 lg n 10 nb ,i ,c n 10 br ,i ,c in dB/m c 1 c 1 2 217 Since the „Number of Vehicles“ D/E/N refer to each daily period (and not per hour) the emission level LE also refers to that period. CadnaA - Reference Manual 2 218 2 2 Chapter 2 - Sound Sources 2.6.6 SRM II where n is the number of train categories using the railway line under consideration, Enbh ,i , c is the emission term for non-braking units for train in each train category (c = 1 to n), in octave band i, h br , i , c E is the emission term for braking units for train in each train category (c = 1 to n), in octave band i, and at assessment height h (h = {0; 0.5; 2; 4; 5} m, dependent on the train category). The emission terms E calculate from: • for braking trains: Ebrh , i , c abrh , i , c bbrh ,i , c logVbr , c 10 lg Qbr ,c Cbb ,imc in dB • for non-braking trains: Enbh ,i , c aih, c bih, c logVc 10 lg Qc Cbb ,imc in dB where: aih, c , bih, c : emission terms for train category c in non-braking conditions, for octave band i, at height h (dB) abrh ,i , c , bbrh ,i ,c : emission terms for train category c in braking conditions, for octave band i, at height h (dB) Qc: mean number of non-braking units of the railway vehicle category concerned (h-1) Qbr,c: Vc: Vbr,c: bb: m: Cbb,i,m: mean number of braking units of the railway vehicle category concerned (h-1) mean speed of passing non-braking railway vehicles (km/h) mean speed of passing braking railway vehicles (km/h) type of track/condition of the railway tracks (-) estimation of the occurrence of track disconnection (-) correction for to track discontinuities and rail roughness (dB) CadnaA - Reference Manual 2 219 Chapter 2 - Sound Sources 2.6.6 SRM II The existing categories provided in the Dutch emission database are differ by propulsion system and wheel brake system as follows: Category Train Classes 2 Train description 1 Block braked passenger trains 2 Disc braked and block braked passenger trains 3 Disc braked passenger trains 4 Block braked freight trains 5 Block braked diesel trains 6 Diesel trains with disc brakes 7 Disc braked urban subway and rapid tram trains 8 Disc braked InterCity and slow trains 9 Disc braked and block braked high speed trains 10 Provisionally reserved for high speed trains of the ICE-3 (M) (HST East) type The next figure shows side views of the train categories and specifies the number of individual units (i.e. locos, carriages or cars). One unit of any given category determines the sound emission. In the case of the trains drawn, the locomotives, carriages or cars act as individual units. In case of integrated passenger trains (category 9), each connected section (i.e. a railcar or a carriage) is regarded as a single unit. SRM II-specific train categories (in brackets: number of carriages/cars per unit). For category 7 a single unit consists of a carriage with 3 bogies (i.e. 6 axles). CadnaA - Reference Manual Train Units 220 2 Chapter 2 - Sound Sources 2.6.6 SRM II 2 In SRM II calculation method, the modification of the predefined train categories („train classes“) with regard to a real train composition with deviating train length, can just be corrected by using the number of units (i.e. locos/carriages/cars) within the periods D/E/N, but not by modifying the train length itself. The train length is not an editable parameter in SRM II. Consequently, the figures „Number of Trains“ to be specified in CadnaA represent the number of individual units (locos/carriages/ cars) within the periods D/E/N. For example, a high speed train of category 9 having 8 carriages and two railcars (locos) has to entered as C09: 8 C09r: 2 With ten trains of this type passing during the daily period the input figures for column „Day“ would be: C09: 80 C09r: 20 CadnaA - Reference Manual 2 221 Chapter 2 - Sound Sources 2.6.6 SRM II Emission Indices a, b octave band with centre frequency [Hz] category index code 1 2 3 3 motor 63 125 250 500 1k 2k 4k 8k 1 2 3 4 5 6 7 8 a 20 55 86 86 46 33 40 29 b 19 8 0 3 26 32 25 24 a 51 76 91 84 46 15 24 36 b 5 0 0 7 26 41 33 20 39 a, v < 60 km/h 54 50 66 86 68 68 45 a, v >= 60 km/h 36 15 66 68 51 51 27 21 b, v < 60 km/h 0 10 10 0 10 10 20 20 b, v >= 60 km/h 10 30 10 10 20 20 30 30 a, v < 60 km/h 72 88 85 51 62 54 25 15 a, v >= 60 km/h 72 35 50 68 9 71 7 -3 b, v < 60 km/h -10 -10 0 20 10 20 30 30 b, v >= 60 km/h -10 20 20 10 40 10 40 40 4 a 30 74 91 72 49 36 52 52 b 15 0 0 12 25 31 20 13 5 a, v < 60 km/h 41 90 89 76 59 58 51 40 a, v >= 60 km/h 41 72 89 94 76 58 51 40 b, v < 60 km/h 10 -10 0 10 20 20 20 20 b, v >= 60 km/h 10 0 0 0 10 20 20 20 5 diesel a 88 95 107 113 109 104 98 91 b -10 -10 -10 -10 -10 -10 -10 -10 6 a, v < 60 km/h 54 50 66 86 68 68 45 39 a, v >= 60 km/h 36 15 66 68 51 51 27 21 b, v < 60 km/h 0 10 10 0 10 10 20 20 6 motor 7 8 b, v >= 60 km/h 10 30 10 10 20 20 30 30 a, v < 60 km/h 72 88 85 51 62 54 25 15 a, v >= 60 km/h 72 35 50 68 9 71 7 -3 b, v < 60 km/h -10 -10 0 20 10 20 30 30 b, v >= 60 km/h -10 20 20 10 40 10 40 40 a 56 62 53 57 37 36 41 38 23 b 2 7 18 18 31 30 25 a 31 62 87 81 55 35 39 35 b 15 5 0 6 19 28 23 19 CadnaA - Reference Manual 2 222 2 Chapter 2 - Sound Sources 2.6.6 SRM II Emission Indices for category 9 octave band with centre frequency [Hz] category 2 index code 63 125 250 500 1k 2k 4k 8k 1 2 3 4 5 6 7 8 71 railcar (=loco) 9, 0 m 9, 2 m 9, 4 m 9, 5 m a 7 14 57 52 57 66 47 b 27 28 12 18 18 15 21 5 a 9 10 1 41 8 17 0 23 b 26 28 36 22 37 34 39 24 a 5 11 13 56 -27 -19 -37 -12 b 27 28 31 15 50 47 53 36 a 11 18 28 28 -50 -41 -84 -34 b 25 26 25 25 59 56 73 45 67 pushed/pulled units (=cars) 9, 0 m 9, 2 m 9, 4 m 9, 5 m a 3 10 57 50 53 62 43 b 27 28 12 18 18 15 21 5 a 3 10 57 46 47 55 37 61 b 27 28 12 18 18 15 21 5 a 1 8 54 40 40 49 30 54 b 27 28 12 18 18 15 21 5 a 3 10 54 0 0 0 0 0 b 27 28 12 0 0 0 0 0 Braking Correction octave band i Cbrake.i.c(in dB) cat = 1, 4, 5 cat =2 cat = 7 cat = 3, 6, 8, 9 1 -20 -20 -8 -20 2 -20 -20 -7 -20 3 -20 -20 -20 -20 4 -2 0 -20 -20 5 2 1 -20 -20 6 3 2 -20 -20 7 8 5 -20 -20 8 9 5 -5 -20 cat: Train Category CadnaA - Reference Manual 2 223 Chapter 2 - Sound Sources 2.6.6 SRM II The correction factor Cbb,i as a function of structures above station compounds or railway track condition (bb) and octave band (i) is: octave band i Superstructure bb (Track Condition) 2 Cbb,i (in dB) bb=1 bb=2 bb=3 bb=4 bb=5 bb=6 bb=7 bb=8 concrete sleepers in gravel wooden sleepers in gravel gravel blocks blocks and gravel contr. rail fixation contr. rail fixation + gravel poured in railway lines 1 0 1 1 6 6 - 6 5 2 0 1 3 8 8 - 1 4 3 0 1 3 7 8 - 0 3 4 0 5 7 10 9 - 0 6 5 0 2 4 8 2 - 0 2 6 0 1 2 5 1 - 0 1 7 0 1 3 4 1 - 0 0 8 0 1 4 0 1 - 0 0 Besides the track condition a roughness correction is applied which is a function of track disconnections. The wheel roughness depends on the type of brake system as a function of the wavelength (radiated frequency is speed related). The model of roughness correction applied in the original SRM II method is not dealt with here as it not included in the calculation of emission in both 2003/613/EC and in CadnaA. The following types of disconnections are available: • • • • Disconnections jointless rails rails with joints 2 switches per 100 m > 2 switches per 100 m SRM II indicates the following maximum speeds per category: Speed (km/h) category 1 2 3 4 5 6 7 8 9 10 v [km/h] 140 160 140 100 140 120 100 160 300 330 CadnaA - Reference Manual 224 2 Chapter 2 - Sound Sources 2.6.6 SRM II These train type specific speed limits are, however, not implemented in CadnaA for the time being. 2 When specifying a track-relevant maximum speed vmax the speed will be adjusted if necessary. In the calculation the smaller of both values is used. Local Train List Train Type The train type is selected from the list Train Types on the Library (global)|Railway Group (also called „Train Classes“). By this selection all relevant parameters are specified. Number of Trains Day/ Evening/Night number of units/vehicles D/E/N. For calculations for mixed evaluation parameters (such as Lden) see chapter 6.2.11.5 "SRM II". Speed v (km/h) relevant speed of trains (km/h) Percentage of breaking vehicles percentage of all vehicles of a train category to be considered as braking vehicles Library with Number of Trains The emission level LAE is not displayed in the dialog Train Class, but on the dialog Railroad (as not all correction factors are known with the dialog Train Class). see chapter 2.6.1 "Common Input Data", section "Number of Trains" CadnaA - Reference Manual 2 225 Chapter 2 - Sound Sources 2.6.7 NMPB-Fer 1996 2.6.7 NMPB-Fer 1996 Note - No printed guideline is available describing the NMPB-Fer 1996 method applied in France to railway traffic. This method, called „NMPB-Fer“, is a calculation procedure implemented only in the former French sound propagation software MITHRA using a emission data set provided by the French national railway institution SNCF. Thus, there is no detailed documentation on the NMPB-Fer emission model available here. This option determines what source height is used in the calculation (attribute TRAM): • option activated: The source height is at 0.05 m above the railhead for all frequencies. • option deactivated: The source height is at 0.8 m above the railhead for frequencies f <= 500 Hz, and at 0.05 m for frequencies f > 500 Hz. This input box is just available when option „Tram“ is activated. The specified ground factor G (0<=G<=1, attribute BABS) is used provided the option „Railways are absorbing (G==1)“ on tab „Ground Absorption“ is activated (see chapter 6.2.7). In case the option „tram“ is deactivated gravel-ballast is assumed. With mixed traffic of normal trains and trams on the same track, either have to be modeled by distinct railway objects. CadnaA - Reference Manual 2 Option „Tram“ Ground Absorption 226 2 2 Chapter 2 - Sound Sources 2.6.7 NMPB-Fer 1996 Emission Lw’ unweighted (linear) sound power level per unit length (1 meter) and per octave (for periods Day/Evening/Night) Total-A A-weighted sum level per period vmax (km/h) When specifying a track-relevant maximum speed vmax the train speed will be adjusted if necessary. In the calculation the smaller of both values is used. Train Classes and Penalties With this option activated, the types of trains and train classes, numbers of trains and corrections, can be edited locally, or an existing list with number of trains can be selected. CadnaA will automatically calculate the emission level from the specified values. The emission data for calculation according to NMPB-Fer is available from a file provided to customers separately. For import of NMPB-Fer specific train classes (format „Mithra Trains“) see chapter 7.2.14 "Special Formats". Type of Track Track Correction (dB): The entered value will be added to the emission spectrum (for all octaves). Local Train List Provided the train classes for NMPB-Fer have been imported the local train list can be edited. CadnaA - Reference Manual 2 227 Chapter 2 - Sound Sources 2.6.7 NMPB-Fer 1996 The train type is selected from the list Train Types on the Library (local)|Railway Group (also called „Train Classes“). By this selection all relevant parameters are specified. Train Type Numbers of trains or units/vehicles during each period. With the same numbers for time periods D/E/N the same power level L’w,i D/E/N results (see also chapter 6.2.11.6). Number of Trains Day/ Evening/Night relevant speed of trains (in km/h) Speed v (km/h) The emission level (sound power per unit length) L’w,i for a train class resulting from the specified parameter is displayed here. Emission Lw,i (dB) see chapter 2.6.1 "Common Input Data", section "Number of Trains" Library with Number of Trains CadnaA - Reference Manual 2 228 2 Chapter 2 - Sound Sources 2.6.7 NMPB-Fer 1996 2 CadnaA - Reference Manual 2 229 Chapter 2 - Sound Sources 2.6.8 NMPB-Fer 2008 2.6.8 NMPB-Fer 2008 2 Dialog Railway (for NMPB-Fer 2008): spectrum is linear, sum-level is A-weighted („Tot-A“). unweighted (linear) sound power level per unit length (1 meter) and per thirdoctave (for periods Day/Evening/Night) Emission Lw’ A-weighted sum level per period Total-A When specifying a track-relevant maximum speed vmax the train speed will be adjusted if necessary. In the calculation the smaller of both values is used. vmax (km/h) With this option activated, the types of trains and train classes, numbers of trains and corrections, can be edited locally, or an existing list with number of trains can be selected. CadnaA will automatically calculate the emission level from the specified values. Train Classes and Penalties CadnaA - Reference Manual 230 2 Chapter 2 - Sound Sources 2.6.8 NMPB-Fer 2008 2 The emission data for calculation according to NMPB-Fer 2008 is available from a separate XML-file containing the relevant train classes. For import of NMPB-Fer 2008 specific train classes (format „NMPB08 Trains“) see chapter 7.2.14 "Special Formats". Type of Track Track Correction (dB): The entered value will be added to the emission spectrum (for all octaves). Slab Track (Gs=0) With this option active, a ground factor Gs=0 is used for the track area. With the option inactive, the ground factor is Gs=1 (i.e. with ballast). CadnaA - Reference Manual 2 231 Chapter 2 - Sound Sources 2.6.8 NMPB-Fer 2008 Provided the train classes for NMPB-Fer 2008 have been imported the local train list can be edited. Local Train List 2 The train type is selected from the list Train Types on the Library (local)|Railway Group (also called „Train Classes“). By this selection all relevant parameters are specified. Train Type Numbers of trains during each period. With the same numbers of trains for time periods D/E/N the same power level L’w,i D/E/N results (see also chapter 6.2.11.7). Number of Trains Day/ Evening/Night relevant speed of trains (in km/h) Speed v (km/h) The emission level (sound power per unit length) L’w,i for a train class resulting from the specified parameter is displayed here. Emission Lw,i (dB) see chapter 2.6.1 "Common Input Data", section "Number of Trains" Library with Number of Trains CadnaA - Reference Manual 232 2 Chapter 2 - Sound Sources 2.6.8 NMPB-Fer 2008 2 CadnaA - Reference Manual Chapter 2 - Sound Sources 2.6.9 CNOSSOS-EU (Railway) 2.6.9 2 233 CNOSSOS-EU (Railway) The emission parameter in CNOSSOS-EU /16/ is the A-weighted longterm average sound pressure level for Day, Evening and Night period, computed by summation over all frequencies: L Aeq,LT 10 lg 10 Le q ,T ,i Ai i 1 dB A where Ai: A-weighting correction according to IEC 61672-1 i: frequency band index (octaves 125 to 4000 Hz) T: time period corresponding to Day, Evening or Night The noise emission of a traffic flow on each track is represented by two source lines, at 0.5 m (h=1) and 4.0 m (h=2) height above the railhead, characterized by its directional sound power level per meter and frequency band (i). That sound power level is the energetic sum of all contributions from all vehicles (t) passing by on the track type (j). These contributions are: CadnaA - Reference Manual Emission Parameter 2 234 2 2 Chapter 2 - Sound Sources 2.6.9 CNOSSOS-EU (Railway) • • • • from all vehicle types (t) at their different speeds (s) under the particular running conditions (constant speed) (c) for each physical source type (rolling, impact, squeal, traction, aerodynamic and additional effects sources such as - for example - bridge noise) (p) using X L W',e q,T ,dir ,i 10lg 10 Lw ',eq ,l in e, x /10 x 1 dB/m LW',eq,line,x is the x-th directional sound power per metre for a source line of one combination of t, s, c, p on each j-th track section. Assuming a steady flow of Q vehicles per hour at an average speed v, an average equivalent number of Q/v vehicles per unit length are passing by. The level LW',eq,line results from: Q L W',eq,line,i , L W,0,dir,i , 10lg 1000 dB/m For each specific source the directional sound power is obtained from: L W,0,dir,i , L W,0,i L W,dir,vert ,i L W,dir,hor,i where LW,dir,vert,i vertical directivity correction, function of angle LW,dir,hor,i horizontal directivity correction, function of angle In the CNOSSOS-EU railway noise model, the input data for the calculation are expressed in 1/3 octave bands (50 Hz - 10 kHz), while the final emission is stated in octave bands (63 Hz - 8 kHz). CadnaA - Reference Manual 2 235 Chapter 2 - Sound Sources 2.6.9 CNOSSOS-EU (Railway) The different physical source types and their heights above railhead: No. Physical Source Type Source Height above Railhead • 2 0.5 m 1 rolling noise (including not only rail and track base vibration and wheel vibration, but also, where present, superstructure noise of the freight vehicles) 2 traction noise 3 aerodynamic noise 4 impact noise (from crossings, switches and junctions) 0.5 m 5 squeal noise 0.5 m 6 noise due to additional effects such as bridges and viaducts 0.5 m separate sound power spectra at 0.5 m (source A) and at 4 m height (source B) 4m The rolling noise is split into four essential compounds: • • • Source Types Rolling Noise wheel roughness, rail roughness, vehicle transfer function to the wheels and to the superstructure (vessels) and track transfer function. CNOSSOS-EU states that traction noise is modeled for two conditions only: constant speed (also to be used at deceleration and acceleration) and idling. In the appendix G, table G-5 /16/, however, just emission data for „idling“ is given. For this reason, the data for deceleration and acceleration were taken from the MS-Excel-files provided with the CNOSSOS-EU project. All four traction noise states are available on the Railway: Train Class dialog (see below): constant speed, accelerating, decelerating, and idling. CadnaA - Reference Manual Traction Noise 236 2 2 Aerodynamic/Impact/ Squeal Noise, Bridges and Viaducts Chapter 2 - Sound Sources 2.6.9 CNOSSOS-EU (Railway) see below Specification of Emission Emission L‘w The emission parameter in CNOSSOS-EU is unweighted sound power level per unit length in third-octaves (for periods D/E/N) /16/. Total-A A-weighted sum level per period vmax (km/h) When specifying a track-relevant maximum speed vmax the train speed will be adjusted if necessary. In the calculation the smaller of both values is used. Source Height When specifying L‘w as emission parameter the source height will be at 0.5 m above railhead (see figure 2.3.a in /16/). The default height of the railhead above ground is 0.6 m (see dialog Geometry via Railway dialog). Train Classes and Penalties With this option activated, the types of trains and train classes, numbers of trains and corrections, can be edited locally, or an existing list with number of trains can be selected. CadnaA will automatically calculate the emission level from the specified values. Examples\ Note that there are no CNOSSOS-EU specific locos, cars/wagons, or train compositions available by default. These have first to be defined or imported from an external file (*.dat) using the Library-Manager (see chapter 12.7), either to the local or the global library of railway classes (see chapter 2.6.12 "Train Class Libraries"). 02_Sources\Railway\train classes for CNOSSOS-EU The train classes to be used with CNOSSOS-EU are provided by DataKustik „as is“ referring to the documentation of the CNOSSOSEU project. The equivalence rail source data is not part of the commission directive /16/. DataKustik refuses, therefore, any liability for the final correctness of the provided datasets. CadnaA - Reference Manual 2 237 Chapter 2 - Sound Sources 2.6.9 CNOSSOS-EU (Railway) The objects listed on the local list of train types (designation starting with „ZZ_...“) are train compositions not being usable in conjunction with CNOSSOS-EU. In CadnaA, train compositions are always displayed independent of the railway standard selected. The track correction LH,TR,i is available for seven types of tracks i (in octaves, see table G-3, appendix G of /16/): Attribute Value FBNR 1 BS Mono-block Sleeper / Soft Pad 2 BM Mono-block Sleeper / Med. Pad 3 BH Mono-block Sleeper / Hard Pad 4 BS Bi-block Sleeper / Soft Pad 5 BM Bi-block Sleeper / Med. Pad 6 BH Bi-block Sleeper / Hard Pad 7 BH Wooden Sleeper Type of Railhead Roughness E EN ISO 3095:2013 (Well maintained and very smooth) M Average network (Normally maintained smooth) For the further types of railhead roughness mentioned CNOSSOS-EU /16/ no values are given in the associated appendix G („N Not well maintained“, „B Not maintained and bad condition“). CadnaA - Reference Manual Type of Track Type of Track The correction for rail roughness Lr,TR,i is available for two types (in octaves, see table G-1, appendix G of /16/): 2 Railhead Roughness 238 2 Noise Reduction at Rail 2 Chapter 2 - Sound Sources 2.6.9 CNOSSOS-EU (Railway) No noise reduction measures at the rail are selectable in CadnaA for the time being due to missing data. Wheel Roughness Though CNOSSOS-EU /16/ mentions several noise reduction measures at the rail (e.g. rail damper, low barrier, absorber plate on slab track, embedded rail) no values are given in the associated appendix G, table G-3 („no measure“ only). The correction for wheel roughness Lr,VEH,i is available for three types (in octaves, see table G-1, appendix G of /16/): Type of Wheel Roughness Cast iron tread brake Composite brake Disk brake Bridge The setting for wheel roughness applies to CNOSSOS-EU railway classes and is, therefore, not selectable on the Railway dialog (see chapter 2.6.12, section "Application CNOSSOS-EU"). The following options to select the coefficients Cbridge for structural radiation are available (not frequency dependent): Attribute Value DBRI Type Cbridge (dB) 0 (no bridge) 0 1 Predominantly concrete or masonry bridges with any trackform 1 2 Predominantly steel bridges with ballasted track 4 CadnaA - Reference Manual 2 239 Chapter 2 - Sound Sources 2.6.9 CNOSSOS-EU (Railway) With activation of this option the correction for curved tracks will be considered based on the following curvature ranges (not frequency dependent): Curvature Range Radius of Curvature (m) 2 Correction (dB) < 300 m 8 300-500 m 5 >= 500 m 0 According to CNOSSOS-EU /16/, squeal contribution shall be applied on railway track sections where the radius is within the ranges mentioned above for at least a 50 m length of track. Specify the number of rail joints per 100 m track length. The coefficients LR,IMPACT,i for impact noise is given in octaves based on wavelength (see table G-4, appendix G of /16/). In order to obtain the roughness level Lr the given wavelength () spectrum is converted into a frequency (f) spectrum by f = v/ , where v is the train speed in km/h. The roughness spectrum as a function of frequency shifts along the frequency axis for different speeds. Rail Joints (1/100 m) n L R,IM PACT ,i L R ,IMPACTSIN GLE ,i 10 lg i 0.01 where LR,IMPACT-SINGLE,i impact roughness level for a single impact per 100 m (see table G-4) joint density ni With this option active, a ground factor Gs=0 is used for the track area. With the option inactive, the ground factor is Gs=1 (i.e. with ballast). CadnaA - Reference Manual Slab Track (Gs=0) 240 2 Aerodynamic Noise 2 Chapter 2 - Sound Sources 2.6.9 CNOSSOS-EU (Railway) Aerodynamic noise is only considered at speeds above 200 km/h. The aerodynamic noise contribution is given as a function of speed (for source heights h1=0.5 m and h2=4.0 m above railhead): v LW ,0 ,i LW , 0,1,i v0 1 ,i lg v0 v LW ,0,i LW ,0 ,2 ,i v 0 2 ,i lg v0 where v0 LW,0,1,i LW,0,2,i 1,i 2,i reference speed 300 km/h reference sound power for sources at 0.5 m height reference sound power for sources at 4.0 heights coefficient for sources at 0.5 m height (1,i = 50) coefficient for sources at 4.0 m height (2,i = 50) Respective values for LW,0,1 and LW,0,2 are given in octaves in table G-6, appendix G of /16/. Other railway-related noise sources CNOSSOS-EU states that various other railway-related noise sources like depots, loading/unloading areas, stations, bells, station loudspeakers, etc. can be present and that these sources shall be modeled, if relevant, by industrial noise sources. CadnaA - Reference Manual 2 241 Chapter 2 - Sound Sources 2.6.9 CNOSSOS-EU (Railway) In order to select CNOSSOS-EU specific locos, cars, or train compositions these need to be defined in the local or global library (see chapter 2.6.12 "Train Class Libraries") or to be imported (see preceding section „Train Classes and Penalties“). Afterwards the train classes or train compositions will be listed on the local train list. Local Train List The train type is selected from the list Train Types on the Library (local)|Railway Group (also called „Train Classes“). By this selection all relevant parameters are specified. Train Type numbers of trains or units/vehicles during each period D/E/N. If the number of trains is given per hour, these values have to be multiplied by the number of hours D/E/N respectively. Number of Trains relevant speed of trains (km/h) Speed v (km/h) selectable states: constant speed, accelerating, decelerating, idling Traction Noise States The emission level (sound power per unit length) L’w,i for a train class or train composition resulting from the specified parameter is displayed here. Emission Lw,i (dB) see chapter 2.6.1 "Common Input Data", section "Number of Trains" Library with Number of Trains CadnaA - Reference Manual 2 242 2 Chapter 2 - Sound Sources 2.6.9 CNOSSOS-EU (Railway) 2 CadnaA - Reference Manual 2 243 Chapter 2 - Sound Sources 2.6.10 FTA / FRA 2.6.10 FTA / FRA 2 Dialog Railway (for FTA/FRA) The emission parameter according to FTA/FRA is the A-weighted equivalent continuous sound pressure level Leq,50ft at 50 feet (15.24 m) distance from the railway’s axis /91//92/. For a single train class, it calculates from the sound exposure level SELi,50ft in dB(A) of sub-source i: len SELi ,50 ft SELref i 10 lg len ref where K lg v v i ref i SELref: reference sound exposure level for sub-source i len: length of train or car/loco, in ft. (internally converted to m) lenref: reference length for sub-source i, in ft. (internally converted to m) K: speed factor v: speed, in mph (internally converted to km/h) vref: reference speed for sub-source i, in mph (internally converted to km/h) The total level SELtot for all sub-sources n of a single train class is: n SELtot 10 lg 10 SELi / 10 i 1 The level Leq,50ft for a single type of train results from (per hour): Leq ,50 ft SELtot 10 lg N CThrottle CTrack 3600 CadnaA - Reference Manual Emission Level 244 2 Chapter 2 - Sound Sources 2.6.10 FTA / FRA where N: number of trains per hour CThrottle: throttle correction (for FTA sources only) with the throttle correction CThrottle (T: throttle setting): 2 0 CThrottle 2T 5 for T 6 for T 6 The total level Leq,50ft,tot for all train types j on a track is: m L / 10 Leq ,50 ft , tot 10 lg 10 eq , 50 ft , j j 1 Track Correction Attribute Value FBNR 1 2 3 4 Type of Track CTrack (dB) 0 5 3 4 (normal) jointed track embedded track on grade aerial structure w/ slab track vmax (km/h) When specifying a track-relevant maximum speed vmax the speed will be adjusted if necessary. In the calculation the smaller of both values is used. Type of Trains The table on the next page lists all FTA/FRA train types. The following abbreviations for the sub-source types apply: Abbreviation Type of Sub-Source HSWH High Speed, Wheel-Rail Interaction HSPR High Speed, Propulsion HSAE High Speed, Wheel Region - Aerodynamic High Speed, Train Nose - Aerodynamic High Speed, Pantograph - Aerodynamic LOCO locomotive source CAR all other types of vehicles (cars, coaches) HORN warning horns CadnaA - Reference Manual 2 245 Chapter 2 - Sound Sources 2.6.10 FTA / FRA Train Types accord. to FRA report (2005) and FTA report (2006), revised FTA train types in bold (as of 2015, see footnotes): Application Type Name Source Height (ft) Source Height (m) FTA/FRA FRA_HS_EL_LOC HighSpeed Electric Locomotive 1 3 1 FTA/FRA FRA_HS_EL_CAR HighSpeed Electric Car FTA/FRA FRA_HS_FF_LOC HighSpeed Fossil Fuel Locomotive Type of Trains (cont.) SELref dB(A) lenref (m) vref (km/ h) SpeedFactor K Source Type 0.30 85 193.2 0.91 75 21.3 144.8 28 HSWH 144.8 15 0.30 85 193.2 144.8 HSPR 28 HSWH HSWH 1 0.30 85 193.2 144.8 20 10 3.05 83 22.3 32.2 10 HSPR FTA/FRA FRA_HS_FF_CAR HighSpeed Fossil Fuel Car 1 0.30 85 193.2 144.8 20 HSWH FTA/FRA FRA_HS_EMU_LOC HighSpeed EMU Locomotive 1 0.30 91 193.2 144.8 20 HSWH FTA/FRA FRA_HS_EMU_CAR HighSpeed EMU Car 1 0.30 91 193.2 144.8 20 HSWH FTA/FRA FRA_VHS_EL_LOC VeryHighSpeed Electric Loc 1 0.30 91 193.2 145 20 HSWH 5 1.52 89 193.2 289.7 60 HSAE 10 3.05 89 22.3 289.7 60 HSAE 12 3.66 86 22.3 32.2 0 HSPR 15 4.57 86 - 289.7 60 HSAE VeryHighSpeed Electric Car 1 0.30 91 193.2 145 20 HSWH 5 1.52 89 193.2 289.7 60 HSAE FTA/FRA FRA_VHS_EL_CAR FTA/FRA FRA_CONV_FRE_LOC Conventional Freight Locomotive 10 3.05 97 27.4 64.4 10 LOCO FTA/FRA FRA_CONV_FRE_CAR Conventional Freight Car 1 0.30 100 609.6 64.4 20 CAR FTA/FRA FRA_CONV_PASS_LOC Conventional Passenger Loco 10 3.05 94 18.2 64.4 10 LOCO FTA/FRA FRA_CONV_PASS_CAR Conventional Passenger Coach 1 0.30 94 152.4 64.4 20 CAR FTA/FRA FRA_HORN Horn 12 3.66 114 - 0 0 HORN FTA/FRA FTA_COMM_LOC_DE Conv. Commuter Locomotive, Diesel-Electric 8 2.44 92 - 80.5 -10 LOCO FTA/FRA FTA_COMM_LOC_EL *1) Conv. Commuter Locomotive, Electric 2 0.61 90 - 80.5 -10 LOCO FTA/FRA FTA15_COMM_LOC _EL *1) Conv. Commuter Locomotive, Electric 2 0.61 90 - 80.5 10 LOCO FTA/FRA FTA_COMM_DMU *2) Conv. Commuter Diesel Multiple Unit 2 0.61 85 - 80.5 -10 LOCO FTA/FRA FTA15_COMM_DMU *2) Conv. Commuter Diesel Multiple Unit 2 0.61 85 - 80.5 0 LOCO CadnaA - Reference Manual 2 246 2 Chapter 2 - Sound Sources 2.6.10 FTA / FRA Type of Trains (cont.) 2 FTA/FRA FTA_COMM_HRN Conv. Commuter Horn 12 3.66 110 - 0 0 HORN FTA/FRA FTA_COMM_CAR Conv. Commuter Car 1 0.30 82 - 80.5 20 CAR FTA/FRA FTA_AGT_ST Conv. AGT - Steel Wheel 1 0.30 80 - 80.5 20 CAR FTA/FRA FTA_AGT_RU Conv. AGT - Rubber Wheel 1 0.30 78 - 80.5 20 CAR FTA/FRA FTA_HORN Horn 12 3.66 113 - - 0 HORN footnotes: *1) The FTA train class FTA_COMM_LOC_EL (Conv. Commuter Locomotive, Electric) uses an incorrect speed factor K=-10, resulting from an data transfer error in the first implementation of FTA in CadnaA. Instead, the train class FTA15_COMM_LOC_EL uses the correct speed factor K=10 corresponding with the value in the FTA-report /91/. *2) The FTA train class FTA_COMM_DMU (Conv. Commuter Diesel Multiple Unit) uses an incorrect speed factor K=-10, resulting from an data transfer error in the first implementation of FTA in CadnaA. Instead, the class FTA15_COMM_DMU uses the correct speed factor K=0 corresponding with the value in the FTA-report /91/. CadnaA - Reference Manual 2 247 Chapter 2 - Sound Sources 2.6.10 FTA / FRA Train Types accord. to FRA-report, revised edition 2012: Application Type Name FTA/FRA FRA12_HS_VHS_EL_LOC HS & VHS Electric Locomotive FTA/FRA FTA/FRA FRA12_HS_VHS_EL_CAR FRA12_HS_VHS_EMU_LOC Type of Trains (cont.) Source Height (ft) Source Height (m) SELref dB(A) lenref (m) vref (km/ h) SpeedFactor K Source Type 1 0.30 91 193.2 144.8 20 HSWH 5 1.52 89 193.2 289.7 60 HSAE 10 3.05 89 22.3 289.7 60 HSAE 12 3.66 86 22.3 - - HSPR 15 4.57 86 - 289.7 60 HSAE HS & VHS Electric Car 1 0.30 91 193.2 144.8 20 HSWH 5 1.52 89 193.2 289.7 60 HSAE HS & VHS EMU Locomotive 1 0.30 91 193.2 144.8 20 HSWH 2 0.61 86 193.2 - - HSPR 5 1.52 89 193.2 289.7 60 HSAE 10 3.05 89 22.3 289.7 60 HSAE 15 4.57 86 - 289.7 60 HSAE 0.30 91 193.2 144.8 20 HSWH FTA/FRA FRA12_HS_VHS_EMU_CAR HS & VHS EMU Car 1 5 1.52 89 193.2 289.7 60 HSAE FTA/FRA FRA12_HS_GT_LOC HS Gas Turbine Locomotive 1 0.30 91 193.2 144.8 20 HSWH 10 3.05 83 22.3 32.2 10 HSPR FTA/FRA FRA12_HS_GT_CAR HS Gas Turbine Car 1 0.30 91 193.2 144.8 20 HSWH FTA/FRA FRA12_CONV_FRE_LOC Conventional Freight Locomotive 10 3.05 97 27.4 64.4 10 LOCO FTA/FRA FRA12_CONV_FRE_CAR Conventional Freight Car 1 0.30 100 609.6 64.4 20 CAR FTA/FRA FRA12_CONV_PASS_LOC Conventional Passeng. Locomotive 10 3.05 92 18.2 80.5 -10 LOCO FTA/FRA FRA12_CONV_PASS_CAR Conventional Passenger Coach 1 0.30 82 25.9 80.5 20 CAR FTA/FRA FRA12_HORN Horn 12 3.66 113 - - - HORN For the time being, the train class MAGLEV (magnetic levitation train) is not available in CadnaA as a source height of -5 feet (i.e. below ground) cannot be selected. CadnaA - Reference Manual 2 248 2 Default Lengths for FRA Train Classes 2 Chapter 2 - Sound Sources 2.6.10 FTA / FRA In FTA report, the default length is the standard length being used in conjunction with the number of vehicles (locos or cars) to correct for the final emission per unit length. When introducing the respective traffic figures for vehicle types (locos, cars) the number of units of this length are concerned. The default length applied by CadnaA for each vehicle type are: Type Name DefaultLength (m) DefaultLength (ft) FRA_HS_EL_LOC HighSpeed Electric Locomotive 21.34 70 FRA_HS_EL_CAR HighSpeed Electric Car 18.59 61 FRA_HS_FF_LOC HighSpeed Fossil Fuel Locomotive 22.25 73 FRA_HS_FF_CAR HighSpeed Fossil Fuel Car 18.59 61 FRA_HS_EMU_LOC HighSpeed EMU Locomotive 22.25 73 FRA_HS_EMU_CAR HighSpeed EMU Car 18.59 61 FRA_VHS_EL_LOC VeryHighSpeed Electric Loc 22.25 73 FRA_VHS_EL_CAR VeryHighSpeed Electric Car 18.59 61 FRA_CONV_FRE_LOC Conventional Freight Locomotive 27.43 90 FRA_CONV_FRE_CAR Conventional Freight Car 20.72 68 FRA_CONV_PASS_LOC Conventional Passenger Locomotive 18.28 60 FRA_CONV_PASS_CAR Conventional Passenger Coach 18.59 61 FRA_HORN Horn - - FRA12_HS_VHS_EL_LOC HS & VHS Electric Locomotive 22.25 73 FRA12_HS_VHS_EL_CAR HS & VHS Electric Car 18.59 61 FRA12_HS_VHS_EMU_LOC HS & VHS EMU Locomotive 22.25 73 FRA12_HS_VHS_EMU_CAR HS & VHS EMU Car 18.59 61 FRA12_HS_GT_LOC HS Gas Turbine Locomotive 22.25 73 FRA12_HS_GT_CAR HS Gas Turbine Car 18.59 61 FRA12_CONV_FRE_LOC Conventional Freight Locomotive 27.43 90 FRA12_CONV_FRE_CAR Conventional Freight Car 20.72 68 FRA12_CONV_PASS_LOC Conventional Passeng. Locomotive 18.28 60 FRA12_CONV_PASS_CAR Conventional Passenger Coach 25.90 85 FRA12_HORN Horn - - In contrary, FTA report does not state a default length. The emission in FTA is per car/loco. Thus, the default lengths in each respective train class are zero. CadnaA - Reference Manual 2 249 Chapter 2 - Sound Sources 2.6.10 FTA / FRA With this option activated, the types of trains and train classes, numbers of trains and corrections, can be edited locally, or an existing list with number of trains can be selected. CadnaA will automatically calculate the emission level from the specified values. Train Classes and Penalties 2 In the following, the procedure to edit a local train list (with numbers of trains) is described. To enter a train list in the local library, see chapter 2.6.1 "Common Input Data", section "Number of Trains". Local Train List The train type is selected from the list Train Types on the Library (global)|Railway Group (also called „Train Classes“). By this selection all relevant parameters, such as train length and speed or percentage of disc brakes, are specified. Train Type Numbers of vehicles/units D/N (E not relevant). In case the amount is given by vehicles/units per hour, this values have to be multiplied by 15 to obtain the figure for Day and by 9 for Night (for FTA/FRA). Number of Trains Day/ Evening/Night relevant speed of trains (km/h) Speed v (km/h) length l of vehicle/unit, deviating from default length (m) Train Length (m) CadnaA - Reference Manual 250 2 2 Chapter 2 - Sound Sources 2.6.10 FTA / FRA As locos and cars are different train classes in FTA/FRA, an entire train consists, normally, of at least two types of train classes. Regarding the input of the length, however, both classes - locos and cars - have to be distinguished. Example 1: A steel-wheeled electric train with 2 power cars and 8 passenger coaches is defined using the FRA-railway group „VHS Very High-Speed“ and the following traffic data: • number of trains: 60 during Daytime (4 trains per hour) In this case, the length entered for locos as well as for cars corresponds to either default lengths (check box „Length“ on dialog „Train Class“ is deactivated). So, the number of vehicles to be entered for each category is: • • number of locos: 120 during Daytime (8 per hour) number of cars: 480 during Daytime (32 per hour) Example 2 corresponds with example 1 regarding the number of trains. The number of vehicles, however, is entered in a different way. As the noise emitted by the pantograph of the locos is linked to the number of locos, the two locos in each train cannot be entered as a single source of type FRA_VHS_EL_LOC while doubling its length. This would lead to a wrong emission as the pantograph’s aerodynamic emission is per vehicle and not per length. So, the service numbers for locos have to be kept. For the cars, however, the 8 passenger coaches per train could be counted as a single unit with a length of 8 * car length (8 * 18.59 m = 148.72 m). In this case, the number of locos and car compositions passing by are: • • number of locos: 120 during Daytime (8 per hour) number of cars: 60 during Daytime (4 per hour) Both ways to specify the emission lead to the same emission level. CadnaA - Reference Manual 2 251 Chapter 2 - Sound Sources 2.6.10 FTA / FRA The FTA-model applies a correction for the throttle setting with dieselpowered locos and Diesel Multiple Units (DMUs) only (see table 6-4, FTAreport). In CadnaA, throttle setting is applied to all sources of type LOCO instead. Consequently, the user has to ensure that the throttle is zero for all other FTA-loco-types besides the two mentioned above. Throttle setting The emission level LeqL(1h) for a train class resulting from the specified parameter is displayed here. Emission Lm,E,i (dB) see chapter 2.6.1 "Common Input Data", section "Number of Trains" Library with Number of Trains CadnaA - Reference Manual 2 252 2 Chapter 2 - Sound Sources 2.6.10 FTA / FRA 2 CadnaA - Reference Manual Chapter 2 - Sound Sources 2.6.11 Further Procedures for Railway Noise 2.6.11 2 253 Further Procedures for Railway Noise Information on the following standards or guidelines for railroad noise can be found in the German version of the CadnaA reference manual: • ONR 305011, Austria • DIN 18005 (1987), Germany • Semibel, Switzerland CadnaA - Reference Manual 2 254 2 Chapter 2 - Sound Sources 2.6.11 Further Procedures for Railway Noise 2 CadnaA - Reference Manual 2 255 Chapter 2 - Sound Sources 2.6.12 Train Class Libraries 2.6.12 Train Class Libraries The global library for train classes (via Tables|Libraries (global)| Railway Groups) provides the emission data of various guideline-specific train classes with their parameters. This library is accessed when editing a local train list (with numbers of trains) on the dialog Railway, but also when compiling a train list in the local library (Tables|Libraries (local)|Numbers of Trains). This global library of train classes can be edited for a number of railway guidelines and extended by the user. As with any global library it is available in any CadnaA project without any further import operation. Table Train Classes (or Railway Groups) from the global library CadnaA - Reference Manual Global Library 2 256 2 Local Library 2 Chapter 2 - Sound Sources 2.6.12 Train Class Libraries In order to use a global train class in a project the required data sets have to be copied to the local library first. Alternatively, the train classes are selectable from the global library via list box „Train Type“ on dialog Railway:Train Class. This depends, however, on the calculation guideline selected as some calculation methods just use the global train classes (e.g. Schall03 (1990), Schall03 (2014), SRMII, ONR 305011, Nordic Prediction Method, FTA/ FRA) while for others the global train classes have to be copied to the local library (e.g. NMPB-Fer 1996, NMPB-Fer 2008, CNOSSOS-EU). For further guidelines the guideline-specific train classes are just coded in CadnaA internally and can, therefore, not be edited (e.g. Semibel, CRN, SRM II). Inserting a new train class In order to define a new train class insert a new line into the local or global library (via the context menu command Insert before/after). With a doubleclick on the new row the edit dialog of the new train class opens. Application Depending on the guideline selected the dialog will be adjusted. The option „Application“ acts as a filter. For example, with the application „Schall 03 (1990)“ selected here, these train classes are available from the list box on the dialog Railway:Train Class, in case Schall 03 (1990) has been selected on the dialog Calculation|Configuration, tab „Country“. CadnaA - Reference Manual 2 257 Chapter 2 - Sound Sources 2.6.12 Train Class Libraries The data box may contain any kind of text. Name This data box must respect the rules applying to CadnaA objects (i.e. no blanks or special characters or symbols, besides the underscore „_“, starting by letters). Train Type/Short Name Some calculation methods for railway noise offer to set up user-defined trains composed of locomotives and wagons/cars (e.g. ONR 305011, Schall 03 (2014), NMPB-Fer 1996/2008, FTA/FRA). When the option „Train Composition“ is selected from the list box, user-defined trains can be edited using the existing train types/classes. Enter in the list the number and the train type/class available from the library of train classes by double clicking in column „Train Type“ and select the train class from the dialog Train Composition. Train Composition Train composition for FTA/FRA: train composed of 2 locos and 8 cars Enter also a name and a short name for train type (see above). When selecting this train composition via the dialog Railroad the entered short name/name will be displayed on the list box „Train Type“. A train composition may consist of 11 lines (data sets) at the most. CadnaA - Reference Manual 2 258 2 Application Schall 03 (1990) 2 Chapter 2 - Sound Sources 2.6.12 Train Class Libraries With the application of Schall 03 the following input data is required to define a new train class: • • • • • Name and Short Name Percentage of Disc Brakes p (%) Speed v (km/h) Length of one (single) train l (m) Type Correction Dfz (dB), alternatively selectable form the list box. Dialog Library:Train Class: new train class for Schall 03 (1990) CadnaA - Reference Manual 2 259 Chapter 2 - Sound Sources 2.6.12 Train Class Libraries The procedure Schall03 (2014) /26/ makes use of relative spectra which are added to the specified A-weighted sum level. In case measured (absolute) spectra are to be used enter zero for the A-weighted sum level. Application Schall03 (2014) 2 The following input data for a new train class are required: • • • type of brake reference speed (in km/h), usually v0=100 km/h reference number of axles For each relevant sub-source m (first column, see table 5, Schall03 (2014)) the relevant octave band level spectrum has to be entered. To this end, enter x for each relevant source height in column „valid“. This activates this subsource. Enter a space to deactivate this sub-source. Dialog Library|Train Class: entering a new train class for Schall03-2014 In the local list „Number of Trains“ (on Railway dialog) the following train classes are listed: • • individual locomotives, cars, carriages, and all trains according to table 4, Schall03 (2014), and train compositions as defined in the global library of train classes, indicated by the prefix „ZZ_“. CadnaA - Reference Manual Train compositions for Schall03 (2014) 260 2 Application Nordic Prediction Method 2 Chapter 2 - Sound Sources 2.6.12 Train Class Libraries Nordic Prediction Method requires spectra of parameters a and b to define a new train class. The following input data is required to define a new train class: • • • Name and Short Name Diesel engine yes/no octave band spectrum for parameters a and b To enter the spectrum click into the respective cell of the table. Dialog Library:Train Class: new train class for Nordic Prediction Method CadnaA - Reference Manual Chapter 2 - Sound Sources 2.6.12 Train Class Libraries NMPB-Fer 1996 requires an octave band emission spectrum to define a new train class. The following additional input data is required: • • • • • Name and Train Type/Short Name Variation of v: equation describing the variation of emission vs. speed (e.g. 30 * log10 (v/vref)) Reference Speed vref (km/h) number of bogies: applies to loco and cars (also several cars) options „Tram“ or „Pneu“ on/off In case both options „Tram“ or „Pneu“ are activated the source will radiate omni-directional, compared to non-pneu trams and other ordinary trains using a pre-defined directivity. To enter the spectrum click into the respective cell of the table Dialog Library:Train Class: new train class for NMBP-Fer 1996 CadnaA - Reference Manual 2 261 Application NMPB-Fer 1996 2 262 2 Application NMPB-Fer 2008 2 Sub-Source Table Chapter 2 - Sound Sources 2.6.12 Train Class Libraries NMPB-Fer 2008 requires multiple third-octave band emission spectrum at several heights (at 0.0, 0.5, and 4.0 m) to define a new train class. The following additional input data is required: • Name and Train Type/Short Name • options „Tram“ or „Pneu“ NMPB-Fer 2008 requires to define sub-sources for a new train class at a single or several heights. In this case, in column „valid“ a letter x is entered to activate that respective row. Type space to deactivate a row. • vref (km/h): reference speed • Slope: variation of emission vs. speed (e.g. „30“ for 30*log10(v/vref)) • Num: number of bogies, applies to loco and cars (also several cars) • third-octave band emission spectrum per sub-source To enter the data click into the respective cell of the table. Dialog Library:Train Class: new train class for NMBP-Fer 2008 CadnaA - Reference Manual 2 263 Chapter 2 - Sound Sources 2.6.12 Train Class Libraries FTA/FRA requires to define sub-sources for a new train class at a single or several heights. In this case, in column „valid“ a letter x is entered to activate that respective row. Type space to deactivate a row. Application FTA/FRA 2 Dialog Library:Train Class: new train class for FTA/FRA Besides the sound exposure level SEL the FRA/FTA-emission model considers: • • • • Emission Model default length (m), used for length correction reference length len_ref (m), used for emission correction reference speed S_ref (km/h) and speed factor K sub-source type (see below) The FRA-source heights for all types of sub-sources result from tables 5-2 and E-1 in the FRA-report. As the source height specified for horns from either tables differ (12 vs. 13 ft), just the height of 12 ft has been considered in the emission table. As far as source height with FTA-source heights are concerned, CadnaA applies a height of 12 ft for horns, of 8 ft for diesel-electric-locos and 2 ft for all other types of sources (see table 6-5 in the FTA-report). The horns as point sources do not require a default length. CadnaA - Reference Manual Source Heights 264 2 Chapter 2 - Sound Sources 2.6.12 Train Class Libraries Default Source Lengths The default source length for FRA-train classes is the physical length of each vehicle (loco, car/wagon), irrespective what reference length len_ref is used to specify the source emission (see chapter 2.6.10). As FTA-report evaluates the emission per car/loco this value is not relevant in this case. Source Types The following source types are used (see FRA-report, tables 5-2 and E-1, and FTA-report, table 6-4): 2 HSWH HSPR HSAE LOCO CAR HORN Option „Length“ High Speed Source - Wheel-Rail Interaction High Speed Source - Propulsion High Speed Source - Aerodynamic (with different heights) locomotive source all other types of vehicles (cars, coaches) warning horns With FTA/FRA train compositions ensure that the option "Length" in each train class is deactivated. This will cause the total length being the sum of all locos and cars. Entering a length for train compositions is not required, nor recommended. CadnaA - Reference Manual 2 265 Chapter 2 - Sound Sources 2.6.12 Train Class Libraries In conjunction with CNOSSOS-EU, it requires first to import or define train classes and/or train compositions in the local or global library of train classes. Subsequently, these will be selectable in the local train list (see chapter 2.6.9) or in the table Number of Trains (see chapter 2.6.1 "Common Input Data", section "Number of Trains"). Train compositions make use of previously defined train classes, e.g. a freight train could be defined based a train class for a single electric loco and a number - say 16 - freight cars, thus making up an entire train. Dialog Library: Train Class: new train class for CNOSSOS-EU With the application of CNOSSOS-EU the following input data is required to define a new train class: • • • Name and Train Type, Short Name Maximum Speed vmax (km/h) Reference Number of Axles and (see next page): CadnaA - Reference Manual Application CNOSSOS-EU 2 266 2 2 Chapter 2 - Sound Sources 2.6.12 Train Class Libraries Parameter Options Vehicle Type o other d1 Diesel locomotive (c. 800 kW) d2 Diesel locomotive (c. 2200 kW) d3 Diesel multiple unit e1 Electric locomotive e2 Electric multiple unit a generic freight vehicle (car) Diesel loc/RENFE Dloco/1155kW Diesel loc/NS6400 Dloco/1180kW Diesel loc/TKOJ JT42CWR/Class66/2.2MW with traction correction w. superstructure correction + + + + + - + Remarks „o other“: any other kind of cars, besides freight cars (i.e. maintenance vehicles etc.) (caption for columns left: + = is included - = is not included) Break Type min max c Cast iron tread brake k Composite brake n Disk brake - Contact Filter min max Axle load 50 kN - wheel diameter 360 mm Axle load 50 kN - wheel diameter 680 mm Axle load 50 kN - wheel diameter 920 mm Axle load 25 kN - wheel diameter 920 mm Axle load 100 kN - wheel diameter 920 mm approx. CRN conditions - Wheel Diameter min max 920 mm 840 mm 680 mm 1200 mm wheel diameter 360 mm not available due to missing data in table G-2 of appendix G /16/ Wheel Measure n no measure no further options provided in /16/ CadnaA - Reference Manual Chapter 2 - Sound Sources 2.6.12 Train Class Libraries The editing of new train classes for the following guidelines is described just in the German version of the CadnaA reference manual: • ONR 305011 CadnaA - Reference Manual 2 267 Application for further guidelines 2 268 2 Chapter 2 - Sound Sources 2.6.12 Train Class Libraries 2 CadnaA - Reference Manual 2 269 Chapter 2 - Sound Sources 2.6.13 Traffic-Count Calculator 2.6.13 Traffic-Count Calculator The Traffic-Count Calculator dialog on the Extras menu enables to redistribute the actual numbers of trains or of flight movements (i.e. traffic counts) for the time periods Day/Evening/Night. 2 Especially with calculations according to the EC-Directive on Environmental Noise the prevailing numbers of trains or flights for Day and Night may be redistributed to the three time periods Day/Evening/Night. The variables for the traffic counts of the three time periods are: nd for Day, ne for Evening, and nn for Night. The redistribution can be applied to: • • • all activated objects „Railway“, all lists for „Numbers of Trains“ (and consequently for all objects „Railway“ referencing a respective train list), and all activated objects „Air Route“. In the example above, the actual traffic counts of the local train lists for Day and Night will be redistributed, resulting in Evening counts being 25% of the Day, plus 20% of the Night. Therefore, the original traffic counts are reduced for the Day to 75% and for the Night to 80%. CadnaA - Reference Manual Example 270 2 Option „Delete AllZero-Lines“ 2 Chapter 2 - Sound Sources 2.6.13 Traffic-Count Calculator When this option is active, all data sets of the selected object type/s containing no data (empty or zero lines) will be deleted upon the next recalculation. This option ensures that non-valid traffic data (e.g. from import operations) is kept and exported afterwards. CadnaA - Reference Manual 2 271 Chapter 2 - Sound Sources 2.7 Parking Lots 2.7 Parking Lots The sound emission of parking lots can be calculated either • according to RLS-90, or • according to the parking lot study by the Bavarian Environmental Agency LfU (several editions available), or • according to the Swiss standard SN 640 578:2006-07. 2 For the calculation of sound propagation, the German road noise standard RLS-90 or the selected guideline for industrial sources may be applied. Depending on selected calculation method the dialog Parking Lot is showing the respective input boxes. Dialog Parking Lot CadnaA - Reference Manual 272 2 Chapter 2 - Sound Sources 2.7 Parking Lots Dialog Options Type 2 The selected type of the parking lot determines whether the road noise standard RLS-90 or the selected guideline for industrial sources is used for calculation of sound propagation („public (RLS)“ or „private (Industry)“). Calc emission according to ... Both, the LfU studies, as well as the Swiss standard SN 640 578: 200607 just represent an emission model, but not a propagation model. The following options are available: • • • • • • RLS-90 /17/ LfU study 1993 /49/ LfU study 1995 precise/approximative /50/ LfU study 2003 separate/non-separate /51/ LfU study 2007 separate/non-separate /52/ SN 640578 /66/ In LfU-study 1995 two types of procedures are described, an „exact“ and an „approximative“ procedure. Using the exact procedure requires the noise from search and passage of vehicles to be modeled using the object „Road“ while the approximative procedure makes use of a global estimate. With respect to the LfU-studies 2003 and 2007 the term „separated“ refers to the separate modeling of the noise by parking events and of the noise from search and passage of cars. In this case, the noise from search and passage of cars has to be modeled by separate roads. In case the so-called „combined“ procedures are used (no „separate“ in the designation) the noise emission modeled includes the correction KD to consider the noise by search and passage of vehicles. Further details on the calculation of emission according to RLS-90, the most recent edition of LfU parking lot study and according to SN 640 578 are given in chapters 2.7.1 to 2.7.3. CadnaA - Reference Manual 2 273 Chapter 2 - Sound Sources 2.7 Parking Lots • input of the emission level L*m,E (dBA) for the time periods Day/Evening/Night • display of the A-weighted sound power level PWL (dBA) for the time periods Day/Evening/Night For calculations according to RLS-90, the editions 1993 and 1995 of the LfU study, and the Swiss Standard SN 640 578 the number of lots is always the relevant reference quantity. In the LfU study 2007, besides the number of lots, also other reference quantities are used (e.g. net sales floor area). Input/Display of Emission 2 Counts, Parking Spaces First, select the type of parking lot via the file selector symbol . Make sure that the select numbers of events refer to the selected guideline. Upon closing the table Parking Lot:Number of Events the reference quantity is shown in the input box to the right of „Reference Quantity“ with LfU-Study 2007 selected. • Number of Parking Spaces: Enter here the number of parking spaces or any other figure in units of the reference quantity. • Number of Spaces per Reference Quantity f: In this box the parking lot type specific figure f according to the table Parking Lot:Number of Events is displayed. Assuming the reference quantity is „1 m² net sales floor area“ and f=0.04, this means that 25 m² net sales floor area is required each single parking space (0.04 * 25 = 1). • Example Events per Hour and Parking Space: In this box the parking lot type specific number of events per hour and parking lot or reference quantity resp. is displayed (as resulting from the table Parking Lot:Number of Events). The number of movements for Day is also used for Evening. The penalty Dp (accord. to RLS-90 and SN 640578) or Kpa (accord. to LfU studies) can be entered or the type of parking lot is selected from the list box (see chapters 2.7.1 to 2.7.3). CadnaA - Reference Manual Penalty for Parking Lot Type 274 2 Chapter 2 - Sound Sources 2.7 Parking Lots Option "incl. Interval Maximum Penalty" In conjunction with private parking lots activating this option - provided a LfU study selected - enables to apply the correction for impulsive noise components Ki depending on the type of parking lot. The value displayed is in this case the sum (Kpa + Ki). Option "Penalty for Road Surface" When using the combined procedure according to LfU study 2007 a correction KStro is used to take different road surfaces into account (direct input or selection from a list). Operating Time (min) With the parking lot type "private (ind)" selected, the operation time (in minutes) can be entered here for parking lots not constantly operational. The time specified refers to the time periods D/E/N as specified on the dialog Configuration, tab „Reference Time“. When this check box is deactivated a permanent emission is assumed. Library with Number of Events The table Parking Lot:Number of Events can be accessed via the dialog Parking Lot or from the Tables menu, Libraries (global)|Parking Lot Movements. The data is saved globally and is thus available for further new CadnaA projects as well. 2 When editing a new data set enter in box „Ref. Quantity“ an informative text string. Enter the „Number of Spaces per Ref. Quantity f“ and the „Events per Hour and Parking Space“ (or per Reference Quantity) for the daily periods Day and Night. The number of events for Day will be used for Evening/ Recreation Time as well. The box „Source“ offers to enter remarks regarding the data’s origin. CadnaA - Reference Manual Chapter 2 - Sound Sources 2.7.1 RLS-90 2.7.1 2 275 RLS-90 The emission value of parking lots in RLS-90 is the mean level L*m,E at 25 m distance from the center point of the parking lot area with unobstructed sound propagation /17/: Emission Value L*m,E L*m,E = 37 + 10 lg (N * n) + DP where N: number of events per parking space and per hour (see below) n: number of parking spaces on the parking lot or on a part of the parking lot DP: correction for different types of parking lots When assessing the number of parking events the approach and departure of a vehicle is counted as one event each. If the condition l <= 0,5 s (l: largest dimension of the parking lot (normally a diagonal), s: distance center point receiver) is not met the parking lot’s area has to subdivided into partial areas i. In case the parking lot’s area is screened the condition to fulfill is: l <= 0,8 s. accord. to RLS-90, table 5: Type of Parking Lot Number of Events per Parking Space and Hour Number of Events per Parking Space and Hour Day (6-22 hours) Night (22-6 hours) park-and-ride parking 0.3 0.06 motorway service area 1.5 0.8 Per default, the number events for period Day are also used for the period Recreation Time/Evening. CadnaA - Reference Manual 2 276 2 Parking Lot Type Chapter 2 - Sound Sources 2.7.1 RLS-90 accord. to RLS-90, table 6: Parking Lot Type 2 Sound Power Level PWL correction Dp in dB Parking: Auto 0 Parking: Motorcycle 5 Parking: Truck / Bus 10 Sound Power Level PWL in dB(A) for the daily periods Day/Evening/ Recreation results from: CadnaA - Reference Manual 2 277 Chapter 2 - Sound Sources 2.7.2 LfU-Study (2007) 2.7.2 LfU-Study (2007) The A-weighted sound power level is the relevant emission parameter with the various Bavarian parking lot studies, however, it cannot be specified directly. CadnaA always displays both emission parameters: • input of the emission level L*m,E (dBA) for the time periods Day/Evening/Night • display of the A-weighted sound power level PWL (dBA) for the time periods Day/Evening/Night Emission For direct input specify the emission level L*m,E (dBA) (individually for the time periods Day/Evening/Night). The value results from sound power level PWL (dBA) according to: Direct Input The sound power level per unit area PWL“ of parking lots calculates according to the „combined procedure“ (i.e. including noise from search and passage of vehicles) according to edition 2007 of the Bavarian parking lot study using number of events /52/: Number of Events where PWL0 = 63 dB(A), initial sound power level for one movement/h on a Park-and-Ride parking lot KPA: penalty for parking lot type KI: penalty for impulsive noise (just for the combined procedure) KD: correction for search and passage of vehicles KStrO: penalty for road surface B: number of reference quantities B0 N: frequency of movements (movements per reference quantity and hour) B · N = number of vehicle movements per hour on the parking lot area S: total area or partial area of the parking lot CadnaA - Reference Manual 2 278 2 Chapter 2 - Sound Sources 2.7.2 LfU-Study (2007) Applying the „separated procedure“ (i.e. including noise from search and passage of vehicles) the correction terms KD and KStrO are dropped. 2 The calculation of parking lot emission according to former editions of the Bavarian parking lot study is not described here. The calculation according to earlier editions is still provided to ensure downward compatibility. Parking Lot Type penalty KPA dB penalty KI dB 0 4 - standard shopping trolleys on asphalt 3 4 - standard shopping trolleys on pavement 5 4 - low-noise shopping trolleys on asphalt 3 4 - low-noise shopping trolleys on pavement 3 4 Parking: Nightclub + Discotheque (includes talking noise and car radios) 4 4 Restaurant 3 4 Fast Food Restaurant 4 4 - Central Bus Terminal (Diesel engine) 10 4 - Central Bus Terminal (natural gas engine) 7 3 Truck Parking 14 3 Parking: Motorcycle 3 4 Type of Parking Lot Park-and-Ride (includes parking areas near residential districts, visitors’ and employees’ parking areas, parking areas at the fringe of the city centre) Parking: Shopping center Parking: Shopping center Central Bus Terminal CadnaA - Reference Manual 2 279 Chapter 2 - Sound Sources 2.7.2 LfU-Study (2007) When assessing impulsive noise according to the German regulation (TALärm /109/) a special time weighting procedure is applied (maximum level in intervals of 5 seconds). To account for this type of time weighting activate the option „incl. Interval Max. Penalty“. The same penalty for impulsive noise Ki is applied for the „separated“ (special case) and for the „combined“ procedure (normal case). Impulsive Noise Both procedures described in the LfU study are implemented in CadnaA: the „combined“ procedure (i.e. including noise from search and passage of vehicles) and the „separated“ procedure (i.e. without noise from search and passage of vehicles). Search/Passage of Vehicles The „combined“ procedure (normal case) applies the correction KD due to search and passage of vehicles: combined procedure 2 where f: parking places per reference quantity B: number of reference quantities (i.e. number of parking spaces, net sales floor area, beds) with: When using the separated procedure the noise level resulting from search and passage of vehicles on the parking lot has to be modeled using the object „Road“. Either the respective traffic counts are known or have to be estimated for the relevant routes. At private parking lots (option „private (ind)“ selected), the roads have to be converted into line sources afterwards to apply the propagation for industrial sources (see chapter 11.13 in the manual „Introduction to CadnaA“). The following conversion rule applies: PWL’ = Lm,E + 19,2 dB CadnaA - Reference Manual separated procedure 280 2 Chapter 2 - Sound Sources 2.7.2 LfU-Study (2007) 2 Road Surface According to LfU study 2007 a velocity of 30 km/h has to be used. When applying the combined procedure the road surface on the parking lot’s has to be specified in addition. Penalty for Road Surface asphalt driving lanes 0 concrete block pavement, gaps < 3 mm 0,5 concrete block pavement, gaps > 3 mm 1,0 water-bound surface (gravel) 2,5 natural stone paving 3,0 Reference Quantity B KStrO dB According to LfU study 2007 the penalty KStrO is not considered with parking lots at shopping centers with asphalt or paved road surface as the level increase due to trolley noise is already taken into account in the penalty KPA for the parking lot type. In LfU study 2007 the following reference quantities B0 are used: • • • 1 parking place, 1 m² net sales floor area, 1 bed When calculating the sound power level of several, distinct parking lots using the same reference quantity (e.g. net sales floor area of a shopping center), the reference quantity B has to be divided up according to the percentage of the parking lot areas. CadnaA - Reference Manual 2 281 Chapter 2 - Sound Sources 2.7.2 LfU-Study (2007) • absolute: In this case, the total number of events per hour has to be specified. Enter for „Number of Ref. Quantities B“ the value B=1. A parking lot of type „motorway service area, refueling, cars“ with 100 movements per hour during Day for the following combinations: • 2 When specifying the absolute number of events/movements, CadnaA applies the product of the number of reference quantities B and the movements D/E/N. When using the separated procedure the same emission level results for B=1 and N=100 movements/h or B=25 and N=4 movements/h (for Day): separated procedure: B=1 with N=100 movements/h and B=25 with N=4 movements/h (Day) cause the same emission level, LwA,Day = 83 dB(A) CadnaA - Reference Manual Example 282 2 Chapter 2 - Sound Sources 2.7.2 LfU-Study (2007) • When using the combined procedure, however, just the input of B=1 and N=100 movements/h (Day) generate the correct emission as the correction for search and passage of vehicles is calculated from the number of movements only: 2 combined procedure: B=1 with N=100 movements/h (Day) and B=25 with N=4 movements/h (Day) cause different emission levels. Just B=1 and N=100 movements/h (Day) yields the correct emission level (KD=0 dB as f*B<=10)! As the combined procedure predicts the correction KD due to search and passage based on the product (f*B), and as the parking lot types with absolute number of events do not have search and passage passage events, it follows from B=1 for the correction KD=0 dB. CadnaA - Reference Manual 2 283 Chapter 2 - Sound Sources 2.7.2 LfU-Study (2007) Parking Lot Types accord. to LfU-Study 2007 Name Reference Quantity B0 No. of Spaces/ RefQ f Events/h/RefQ Day N Events/h/RefQ Night N park-and-ride parking city nonchargeable 1 Parking space 1.00 0.300 0.060 park-and-ride parking nonchargeable 1 Parking space 1.00 0.300 0.100 motorway service area, refueling, cars absolute 1.00 40.000 15.000 motorway service area, refueling, trucks absolute 1.00 10.000 6.000 motorway service area, resting, cars 1 Parking space 1.00 3.500 0.700 motorway service area, resting, trucks 1 Parking space 1.00 1.500 0.500 housing estate, underground parking 1 Parking space 1.00 0.150 0.020 housing estate, parking 1 Parking space 1.00 0.400 0.050 discotheque 1m² Net public floor area 0.50 0.020 0.300 consumer market small 1m² Net sales floor area 0.07 0.100 0.000 consumer market big 1m² Net sales floor area 0.07 0.070 0.000 discounter and beverages market 1m² Net sales floor area 0.11 0.170 0.000 white goods market 1m² Net sales floor area 0.04 0.070 0.000 do-it-yourself (DIY) store and furniture market 1m² Net sales floor area 0.03 0.040 0.000 public house in city 1m² Net public floor area 0.25 0.070 0.020 public house rurally 1m² Net public floor area 0.25 0.120 0.030 Tavern 1m² Net public floor area 0.25 0.100 0.100 Fast Food restaurant 1m² Net public floor area 0.25 0.400 0.150 Drive-In absolute 1.00 40.000 6.000 hotel (beds <100) 1 Bed 0.50 0.110 0.020 hotel (beds >100) 1 Bed 0.50 0.070 0.010 CadnaA - Reference Manual 2 284 2 2 Chapter 2 - Sound Sources 2.7.2 LfU-Study (2007) car park city chargeable (max 2 h) 1 Parking space 1.00 1.000 0.030 car park city chargeable 1 Parking space 1.00 0.500 0.010 CadnaA - Reference Manual 2 285 Chapter 2 - Sound Sources 2.7.3 SN 640 578 2.7.3 SN 640 578 The A-weighted sound power level LW,i of a parking lot according to SN 640 578 (edition 2006-07) calculates from /66/: Emission where LW,PVi: sound power level per movement and hour of a parking lot type with area i, in dB(A) dMi: traffic correction, in dB In CadnaA, an initial sound power level of LW,PV=66 dB(A) is used in conjunction with a correction for the type of parking lot KPA (see below): The traffic correction results from: where Bsub area i: number of events on sub-area i per hour (for Day/Night separately) nsub area i: number of parking spaces on sub-area i For direct input specify the emission level L*m,E (dBA) (individually for the time periods Day/Evening/Night). The value results from sound power level PWL (dBA) according to: CadnaA - Reference Manual Direct Input 2 286 2 Chapter 2 - Sound Sources 2.7.3 SN 640 578 Parking Lot Type Attribute Value PARTNR 2 Parking Lot Type LW,PV dB(A) Correction for Parking Lot Type DPA in CadnaA dB *3) Level Correction for Shopping Trolleys *4) 1 Commercial Traffic 66 0 2 2 Park and Ride 66 0 2 3 Service Provider 66 *1) 0 2 4 Shopping Traffic 67 *1) 1 2 5 Leisure Activities 68 *1) *2) 2 2 6 Residents and Visitors 67 *1) 1 2 7 Waiting and Assembly Areas 68 *1) *2) 2 2 8 Miscellaneous 67 *1) 1 2 9 Cars 76 10 1 10 Trucks 78 12 - 11 Motorcycles 69 3 - *1) The sound power level includes noise due to door and hatch slamming. *2) The sound power level includes noise due to car radios. *3) with reference to the initial sound power level of LW,PV= 66 dB(A) *4) The level correction for the use of shopping trolleys has to corrected for in CadnaA manually by the user via the correction for the parking lot type Dp. Search/Passage of Vehicles When calculating the immission level the noise due to search and passage of vehicles is accounted for automatically by: : : CadnaA - Reference Manual 2 287 Chapter 2 - Sound Sources 2.7.3 SN 640 578 The noise due to the passage of vehicles is modeled using the object „Road“. According to SN 640 578 a velocity of 30 km/h has to be used. Passage of Vehicles The noise due to cars entering and leaving the parking lot is not considered in CadnaA. Entry & Exit Noise The implementation in CadnaA only refers to the modeling of socalled „uncovered parking lots“ according to SN 640 578. The other noise sources specified in this standard (underground car park, parking garage) are not implemented. CadnaA - Reference Manual 2 288 2 Chapter 2 - Sound Sources 2.7.3 SN 640 578 2 CadnaA - Reference Manual Chapter 2 - Sound Sources 2.8 Pass-By of individual Vehicles 2.8 Pass-By of individual Vehicles CadnaA offers to calculate for roads, railways, and line sources the time history of the sound pressure level that would result from a single vehicle with a specified emission passing by, according to the selected standard. The command Pass-By Level in the context menu of those types of line source is only available if at least one receiver has been inserted. For example, generating this pass-by level history enables to check: • whether the effect of a noise-control device, such as a barrier, would be sufficient for all affected partial areas, or • which noise reduction may be expected by providing a reflecting building facade with absorbent cladding, or • by which amount the sound pressure level resulting from single motor vehicles traveling by is reduced if - for example - a zone with a speed limit of 30 km/h is established in an ordinary inner-city street. 2 289 The feature „Pass-By Level“ is not available in conjunction with the angle-scanning method (see chapter 6.2.2). CadnaA - Reference Manual 2 290 2 Chapter 2 - Sound Sources 2.8 Pass-By of individual Vehicles DIALOG OPTIONS 2 Receiver Select the name of the receiver point where the pass-by level shall be calculated. Source Type The available option depend on the type of object from the context menu of which the command Pass-By Level was selected. all object types: Userdefined The option „user-defined“ is always available (for roads, railways and line sources). In this case, all parameters can be specified individually. Subsequently, the source is running along the route with the specified speed and sound power level. Object „Road“: light or heavy The sound power level of cars („light“) or trucks („heavy“) is determined based on the speed specified on the dialog Road (see below). The sound power levels correspond with the specifications in RLS-90 /17/. Object „Railway“: train class The length of the vehicle is not relevant for the calculation of the passby level, but is only used in the animation. On the list box all train classes from the dialog Railway are listed. When selecting a specific train class the sound power level is calculated according to the specifications of Schall 03 (1990) /23/ (see below). Emission/Sound Power Level Object „Road“ The sound power level for cars („light“) and trucks („heavy“) calculates from: v LWA 1 car Lm , E 1000 cars / h 19.2 dB 10 lg cars 1 / km h v LWA 1 Lkw Lm, E 1000 Lkw / h 19.2 dB 10 lg Lkw 1 km / h CadnaA - Reference Manual 2 291 Chapter 2 - Sound Sources 2.8 Pass-By of individual Vehicles On the following table, the sound power level for cars and trucks is given as a function of the speed are listed addressed to a single vehicle of each category based on the emission value Lm,E according to RLS-90 (see chapter 2.4.2). Vehicle Category Emission Parameter light (car) heavy (truck) 2 Speed in km/h 30 50 80 100 120 Lm,E 58,5 60,8 64,8 67,2 69,4 LWA 92,5 97,0 103,0 106,4 109,4 Lm,E 71,5 74,3 76,9 - - LWA 105,5 110,5 115,1 - - Examples: • car at 100 km/h: LWA 1 car 67.2 19.2 10 lg100 106.4 dB ( A) • truck at 80 km/h: LWA 1 truck 76.9 19.2 10 lg80 115.1 dB ( A) After selection of a train class the sound power level calculates from: s v LWA 1 train Lm, E 1 train 19.2 dB Railway Corr 10 lg 10 lg 16 h * 3600 h 3 .6 where • • • • • Lm,E: emission level at 25 m from the railway’s axis (according to Schall 03) 19.2 dB: relationship between the emission level Lm,E and the sound power level per unit length PWL’ (according to Schall 03) Railway Correction: When the option „Strictly according to Schall 03“ is enabled (see Section 6.2.11.1), a correction of 5 dB is considered. Otherwise, the value entered on tab „Railway“ is used. v: train speed in km/h 16 h: A time correction is applied as the emission in Schall 03 refers to a time interval of 16 hours. This correction is a constant. CadnaA - Reference Manual Object „Railway“ 292 2 Chapter 2 - Sound Sources 2.8 Pass-By of individual Vehicles Thus, the sound power level per unit length LWA’ for a single train with train length l (m) is: 2 l LWA ' 1 train LWA 1 train 10 lg 1 m Example emission of an ICE train with a railway correction of 5 dB: The sound power levels LWA and LWA’ result from: 250 LWA 1 train 50.2 19 .2 5 10 lg 47.6 130 .4 dB( A) 3 .6 420 LWA ' 1 train 130.4 10 lg 104.2 dB ( A ) 1m Object „Line Source“ When selecting the command Pass-By Level from the context menu of a line source, the sound power level can be entered directly after selecting the option „user-defined“. CadnaA - Reference Manual 2 293 Chapter 2 - Sound Sources 2.8 Pass-By of individual Vehicles Both, the sampling time and the speed determine the section lengths through which the fictitious vehicle or the source moves from one location to the next. A sampling time of 1 s may be sufficient to check for the required calculation time, a value of 0.1 s may be appropriate to represent a level record showing all level variations due to shielding and reflections. Sample Time The direction of traffic can be specified with respect to the direction in which the road was inserted. „Positive“ (pos) means the driving direction is from the first to the last point of the geometry, „negative“ (neg) vice versa. Driving direction negative/positive By this option several pass-bys can be simulated consecutively with their level history getting appended to each other. Keep the dialog Pass-by Level displayed and mark once again the same object or a different one with the right mouse button and select again Pass-By Level from the context menu. Activate the option „Append to Diagram“ and select for the driving direction „negative“ or „positive“. Append to Diagram By clicking and dragging the mouse arrow inside the diagram with the left mouse button depressed in a horizontal direction the vehicle symbol will be moved along the source line in the graphics. Pass-By Diagram Alternatively, select a value from the Animation menu. The pass-by then will start running automatically with the selected speed. CadnaA - Reference Manual 2 294 2 Auralisation Chapter 2 - Sound Sources 2.8 Pass-By of individual Vehicles Hardware requirement: sound card and loudspeaker or headphones On the menu Auralization|Properties the saved sound file of the relevant process is opened after selection of a sound type in the list box and is reproduced - regarding volume - according to the calculated time history of the pass-by level. 2 3D-Auralisation By the option „3D-Auralization“ the Doppler effect - when switching from approach to departure (by „Direction of Motion“ - will be simulated in a realistic way. Listening direction at Receiver Point Automatically to source: viewing directly towards the source (with the shortest distance) Direction (°) view at the given angle towards the source, relative to the x-axis Calibration Select the desired volume from the list box and adjust the corresponding playback on your audio device. CadnaA - Reference Manual 2 295 Chapter 2 - Sound Sources 2.8 Pass-By of individual Vehicles Example • Test the Pass-By with a simple arrangement as in the following figure. Examples\ 02_Sources\ Road\Pass-By.cna Road with buildings and a receiver • Open the context menu by clicking the road axis with the right mouse key and select the command Pass-By Level. • From the list box „Receiver“ select the desired receiver for which the pass-by level shall be calculated - in our example IP1. • In the next box „Source Type“ select „light“. • Adjust the sampling interval to 0.1 s. • After confirmation with OK the diagram opens with the calculated level’s time history. The calculation time depends on the complexity of the project. CadnaA - Reference Manual 2 296 2 Chapter 2 - Sound Sources 2.8 Pass-By of individual Vehicles 2 For a light vehicle calculated level time-history • Now move the mouse cursor in the diagram and press the left mouse button. On this position a vertical cursor line appears, whose time and sound pressure level is indicated in the upper dialog bar and a symbol (black box) indicates the vehicle’s position on the road in the graphic, in the driving direction on the road. • When dragging the cursor line horizontally ins the diagram the vehicle’s symbol will move along the road. • Alternatively, select a value from the Animation menu. Regarding the vehicle’s position relative to the location of buildings reflections (increases in level) and shielding effects (reductions in level) can be realized by respective level changes. CadnaA - Reference Manual Chapter 2 - Sound Sources 2.8 Pass-By of individual Vehicles The level’s time history can be copied to the clipboard to be pasted into other software (e.g. like MS-Excel or MS-Word), either as sequences of numbers or as a chart. • To this end, activate the Level-Time diagram on dialog Pass-by Level by clicking onto it. The upper dialog bar gets highlighted. Now copy to the clipboard by clicking the „Copy“ button (or by pressing the C key). • Paste the data into the other software and confirm either graphic or text. Indicating the vehicle on the road with a symbol (black box) and in the diagram with a vertical cursor line • Check for further options on the Pass-By dialog. • Vary the reflection of single buildings by switching them on and off alternately and watching the effect on the level’s time history. This diagram also facilitates the optimization of barriers, because the effect of a modification can be assessed immediately. Beyond the mere consideration of time-averaged levels, the pass-by feature offers a tool which enables to examine and visualize the effects of level-reducing measures on the actual level. CadnaA - Reference Manual 2 297 Copy the Level’s Time History 2 298 2 Chapter 2 - Sound Sources 2.8 Pass-By of individual Vehicles Video The pass-by can be recorded as a video using AVI format for replay using any standard video software (such as Windows Media Player). Click the button „Video“ to configure the recording options. Video Options • Section: An existing and named section can be selected which is used for the video output (standard: entire limits). It is useful to define a calculation area within that section. • Option „follow source“: With this option activated the video section follows the moving point source. • Scale: Upon activation of the entered scale is used, otherwise the scale defined in the project (default value 1:1000). • Resolution (dpi): When activated and with a value entered, this resolution is used, otherwise the setting on the main window is used. The larger the value, the finer the resolution and the greater the file size (default value 75 dpi). • Frame rate (fps): default value 15 fps 2 A bitmap used as a background image will not be displayed in the video. To record a video, a respective compression algorithm (video codec) has to be specified after having entered a file name. After confirming with OK the pass-by is calculated and recorded. CadnaA - Reference Manual 2 299 Chapter 2 - Sound Sources 2.9 Optimisable Source 2.9 Optimisable Source This type of source requires option BPL. BPL stands for „Back-Tracing of Power Levels“. 2 This object enables to enter an area source the emission of which is maximized by an optimization procedure. The characteristics of this type of source are: • In the calculation, the area of the optimisable source is segmented into sub-areas in the same way as with the general area source (see chapter 2.1) taking into account the receiver distance and screening objects. Each subarea is replaced by a point source. • The configuration option on the „Industry“ tab „Obstacles within Area Sources do not shield“ (see chapter 6.2.9) shall be activated when determining noise quotas using the optimisable source. This will cause screening objects inside the optimisable source’ area not to affect its emission. • On the dialog Optimisable Source, switch from Day to Night depending on what period shall be used in the optimization. The specified sound power refers to the selected period (sound power level PWL or sound power level per unit area PWL“). • The further input parameters at the bottom of the dialog differ from the "normal" area source. These parameters are required for the optimization with respect to the allocation of noise quotas (or noise allotment). Dialog Options CadnaA - Reference Manual 300 2 Period Day/Night 2 Chapter 2 - Sound Sources 2.9 Optimisable Source Select the daily period which shall be used in optimization (Day or Night). The specified sound power refers to the selected period. The optimization procedure in conjunction with noise allotment occurs in CadnaA for the levels Ld (Day) and/or Ln (Night) only. This means that mixed level (such as Lden or Lde) cannot be used for an optimization calculation, since the emissions of the partial periods can not be optimized separately. Therefore, make sure that the levels Ld and Ln are selected for the first two evaluation parameters on tab „Evaluation Parameters“ (see chapter 6.2.5). In case a mixed level is selected as the first evaluation parameter (e.g. Lde), the optimization occurs, however, for the level Ld. When the optimisable source is converted afterwards into a normal area source, the receiver level increases by 1.93 dB assuming that the same emission level Day=Evening/Recreat.Time was specified and, for example, with 13 hours for the Day period, 3 hours for the Night period and a penalty of 6 dB for the Evening/Recreat.Time (here with Ld=Le=60 dB (A)): Therefore, when optimizing the daytime level Ld and after having converted the optimisable source into an area source whose emission shall be - in this example - decreased by 1.93 dB in order to respect the limiting value given as Lde, again assuming the same emission during Day and Evening/Recreation Time. CadnaA - Reference Manual 2 301 Chapter 2 - Sound Sources 2.9 Optimisable Source Enter alternatively the sound power level PWL or the the sound power level per unit area PWL". Power Level PWL or PWL" This option is activated by default. In this case, a change in emission cause an immediate effect. Option „Apply immediately" The usability function assigns a usability value w% to any sound power level per unit area. The continuous shape of the usability function is approximated in CadnaA by two straight lines and a salient point. Salient Point of Usability Function Via these input boxes the emission of the optimisable source can be restricted: Range PWL",min to PWL",max • PWL",min: This value is the minimum required emission. It is determined based on the absolutely necessary noise-relevant processes (e.g. a 10-minute truck ride across an area of 1000 m² results in a PWL"= 55 dB(A)). • PWL",max: This value is the maximum exploitable emission (depends on the branch of industry and may be up to 80 dB(A) for industrial installations with permanent truck traffic). After optimization the slider control bar is at the location of the resulting emission value the value of which is displayed on the top of the dialog. This button is no longer effective as the option "Apply immediately" is always activated. Button "Apply" When clicking this button the sound power of the actual optimisable source is optimized with respect to all active receiver points. In this case, the emission of all further optimisable sources is no changed. To optimize all optimisable sources in a project at once select the command Optimize Area Sources on the Calculation menu. Button "Optimize" CadnaA - Reference Manual 2 302 2 Noise Allotment Chapter 2 - Sound Sources 2.9 Optimisable Source CadnaA supports this optimization in a flexible manner without applying a specific fixed optimization strategy, but by use of user-definable usability function. The optimization procedure aims at determining the permissible emissions, ensuring that 2 Usability Function • the relevant limiting values at receiver points in the vicinity are respected, and • the intended use of the individual areas is not restricted as far as possible. In order to achieve this, a usability function is assigned to each area. The decreasing slope of the function with increasing sound power level means that a further increase in emission cannot be exploited due to the intended use. On the other hand, the usability decreases excessively when a particular emission required for the intended use is further reduced. CadnaA - Reference Manual Chapter 2 - Sound Sources 2.9 Optimisable Source • • Power Level PWL" (dBA) at the salient point: The emission value where the gradient of the usability function changes. A reduction of the power level by 1 dB below this point results in an even stronger reduction in usability than the same reduction above the salient point. Enter here the value that should be "retained" in the optimization (default value: 60 dBA). Usability K (%) at the salient point (default value: 80%) Due to this concept the individual requirements can be accounted for in the maximization /99/. The usability function of CadnaA is approximated by two lines. This requires three emission values for each partial area as a basis for the maximization. The usability specified at the turning point determines the curve and thus the "maximizing strategy". Common data for industrial areas is: PWL’’ min 57 dB(A) Turning Point 80 % / 60 dB(A) PWL’’ max 65 dB(A) The bottom part of the edit dialog for the optimisable source contains a horizontal scroll bar enabling to select an emission value within the range from min to max like. The current value which is displayed in the dialog above. For a first test, push the slider to the extreme right, thus selecting the maximum emission value. CadnaA - Reference Manual 2 303 2 304 2 Calculation 2 Chapter 2 - Sound Sources 2.9 Optimisable Source The most critical receiver points are entered with their relevant limiting levels. Clicking the calculator icon on the toolbar starts the calculation. If no receiver turns red either for day, nor for night, this means that the limiting levels are respected using the maximum value assumed. In this case, no further reduction of the emission is necessary. In the calculation, all sources existing in the project - roads, railways, industry or aircraft noise - are taken into account. By the deactivating objects using groups (see chapter 14.3) different scenarios can be analyzed. The procedure described so far is the same as for the calculation of ordinary area sources. 65.0 65.0 (10/10) (250/10) 70.0 So far, the described procedure does not differ from the calculation of normal area sources. CadnaA - Reference Manual 2 305 Chapter 2 - Sound Sources 2.9 Optimisable Source The red color shows that the limiting level is exceeded at a receiver point. In this case, reduce the emission of the optimisable source with the strongest noise impact on the relevant receivers in steps. Manual Optimization 2 CadnaA does not require a new calculation for each step. Double-clicking the respective optimisable source and shifting the position of the slider will show the resulting change at the receivers immediately. Depending on the desired strategy, the emission values can be reduced until compliance with the standard levels is ensured at all receiver points. Apply this procedure separately for day-time and night-time as required. Selecting the command Optimize Area Sources on the Calculation menu causes to start an automatic, iterative reduction of the emission values. It is always the reduction of emission resulting in the smallest decrease of the arearelated usability according to the concept explained above which is carried out in this step-by-step procedure. With Si area in m² of the ith partial area wi area-related usability in % of the ith partial area the total usability is w wi S i Si This value is displayed at the beginning and the end of the maximization. After optimization, the position of the horizontal scroll bar represents the emission optimum value and is displayed in the top of the dialog. The iteration step width is 0.1 dB by default. Alternatively, the iteration step width can be controlled using a local text block (Name: BPL), for example, in order to optimize the calculation time. The text DELTA_L=1.0 sets - for example - the iteration step width to 1 dB. CadnaA - Reference Manual Automatic Optimization 306 2 2 Chapter 2 - Sound Sources 2.9 Optimisable Source The result calculated by CadnaA needs not be the best if further aspects, not included in the usability function, are to be considered. In this case, the automatic optimization is a suitable starting point, whereas manual modifications of the emission values using the slider enable to further adapt the scenario in the required way. see also: chapter 6.2.13 "Optimizable Source Tab" CadnaA - Reference Manual 31 Chapter 3 - Obstacles Chapter 3 - Obstacles 3 In CadnaA, the following types of objects cause a screening effect in the calculation of propagation, depending on the standard or guideline selected for each noise type: • • • • • • • • building, cylinder, barrier, bridge, embankment, ground absorption area, built-up areas and foliage, 3D-reflector. The following types of obstacles may also have reflecting properties: • • • • building, cylinder, barrier, 3D-reflector. In order to specify the reflectivity of the surfaces of obstacles three options are available in CadnaA. Reflection Properties No reflection is calculated for this object. This is the default setting. No Reflection CadnaA - Reference Manual 2 3 Chapter 3 - Obstacles The subsequent options require that on dialog Calculation|Configuration, tab „Reflection“ (see chapter 6.2.8) at least the reflection order 1 has been selected. 3 Reflection Loss Enter the reflection loss in dB due to reflection or click the file selector symbol to select from a predefined list of surface classifications (resulting from RLS-90, table 7 /17/).. Dialog Building: specifying the reflection loss Absorption Coefficient Alpha With this option activated, a single-number value, a formula, or the reference to an absorption coefficient spectrum (see chapter 12.1 Local and Global Libraries) can be specified. The reflection loss RL is evaluated from the absorption coefficient Alpha according to: CadnaA - Reference Manual 33 Chapter 3 - Obstacles 3.1 Building 3.1 Building Buildings are modeled as a sequence of walls raising vertically from the ground and forming a closed polygon. The floor plan can be of any shape, a rectangular shape can be enforced however (action/command Force Rectangle, just applies to buildings with four polygon points, see chapter 11.4 in manual „Introduction to CadnaA“). By default, buildings are modeled without a roof plate, although this is displayed in the 3D-Special view (see chapter 9.14). For sources above roof level the ground attenuation results from the source height above ground and not above roof (as the roof is not a reflecting surface). There are no roof ridges and no gable walls considered by default as the building is modeled from a series of barriers of the same height and having no roof („open box“). In order to include the screening effect by the ridge, it is recommended to enter a barrier along the ridge line inside the building’s floor plan with a height corresponding to the ridge height (see chapter 3.1.5). To account for the screening effect by gable walls additional polygon points of the building polygon are entered (CTRL key). The height is specified using the option „Height at every Point“ via the dialog Geometry of the building (see chapter 3.1.5). CadnaA - Reference Manual 3 Roof ridge and gable walls 4 3 Internal Sources Chapter 3 - Obstacles 3.1 Building Before starting the calculation, CadnaA performs a consistency check (see chapter 5.1.1) checking for sources inside the building’s floor plans. If so, a message will be displayed. 3 Result of the Consistency Check Ignoring the message (by clicking the „Continue“ button), the building’s outer walls will be considered as barriers diffracting the sound across the barrier’s top edge. So, in this case again, the roof is acoustically not existent by default. This restriction is due to the procedures in the respective calculation standard or guidelines, and not a restriction specific to CadnaA. In order to model the sound radiation from buildings, vertical area sources are attached to the building’s facade the emission of which can be specified based on the interior level (see chapter 6.1 in the manual "Introduction to CadnaA" and see chapter 12.1.2 in this manual). CadnaA - Reference Manual 35 Chapter 3 - Obstacles 3.1 Building Dialog Options 3 Dialog Building see chapter 4.4.2 in the manual "Introduction to CadnaA" Name, Memo-Window, ID, ObjectTree By default, buildings are not reflecting sound (option „No Reflection“). Selecting one of the options „Reflection Loss“ or „Absorption Coefficient Al- Reflection Loss/ Absorption Coeff. Alpha pha“ enables to specify via the respective file selector symbol either a reflection type (according to RLS-90 /17/) or to address an absorption spectrum from the local or the global (by SHIFT-clicking) library of absorptions. In this case, reflections from the building’s surface are taken into account applying the image source method, provided that on tab „Reflection“ (see chapter 6.2.8) in the configuration of calculation at least the first order of reflection is selected. see chapter 3.1.1 Option „Residential Building“ see chapter 3.1.2 Acoustical Transparency (%) CadnaA - Reference Manual 6 3 Button "Geometry" Chapter 3 - Obstacles 3.1 Building Via the button „Geometry“ the building’s height is specified (see chapter 4.2). 3 Buildings lifted from the ground can be entered using the geometry option „absolute Height/Ground at every Point“. Those „floating“ buildings are also displayed on the 3D-Special view as lifted above ground. By contrast, in the calculation the ground will be automatically triangulated to the base line of the building causing a screening effect below the building. Background of this phenomenon is diffraction model used by all existing which do not cover screening objects lifted from the ground. Further, this is due to the normative restriction that by default - no reflective surfaces in the z direction exist besides the ground. Examples\03_Obstacles\Building\Building Height Ground at every Point.cna Building floating above the ground, defined using the geometry option „Height/Ground at every Point" Level distribution on the vertical grid: The ground is triangulated to the base points of the house causing a screening effect CadnaA - Reference Manual Chapter 3 - Obstacles 3.1 Building 37 The option „Sources in Buildings/Cylinders do not shield“ is available for industrial sources (see chapter 6.2.9 "Industry Tab"). Sources in Buildings do not shield The command Deactivate point objects in buildings (from Extras menu) offers to deactivate point like objects (e.g. height points, point sources) laying inside of the building polygons. This feature can be applied after import operations in order to delete all deactivated objects afterwards using the command Modify Object (see manual „Introduction to CadnaA“). Deactivate Point Objects in Buildings Further chapters regarding buildings: • • • • • • • • • command Edit Facades (see chapter 3.1.4) Defining a roof ridge (see chapter 3.1.5) command Generate Building (see chapter 3.1.6) action/command Force Rectangle on the dialog Modify Objects and on the context menu (see chapter 11.4 , see manual „Introduction to CadnaA“) entering receivers along facades (see chapter 5.1, section "Entering receivers at a building’s facade") Snap Point on Building Facade (see chapter 3.1.3) Building Evaluation (see chapter 5.4) Building Noise Map (see chapter 5.4.1) Import Building Height Points (see chapter 7.2.17) CadnaA - Reference Manual 3 8 3 Chapter 3 - Obstacles 3.1 Building 3 CadnaA - Reference Manual 39 Chapter 3 - Obstacles 3.1.1 Residential and non-residential Buildings 3.1.1 Residential and non-residential Buildings By default, a building gets marked as a „Residential Building“. For other types of buildings this options may be deactivated. When calculating the population density (using option XL, see chapter 15.4) only the residential buildings are considered. Option „Residential Building“ Residential buildings and non-residential buildings may use different hatchings. Graphical Appearance Residential building and non-residential building with different filling There are two ways to achieve this: • For this, create a second layer of type „Simple“ for the object type „Building“ on the Appearance dialog (on the Options menu, see chapter 9.5) with a different filling and enter the following expressions: WG_NUM == 0 (for non-residential buildings) and WG_NUM! = 0 (for residential buildings). Dialog Appearance for object type „Building“ CadnaA - Reference Manual 3 10 3 Chapter 3 - Obstacles 3.1.1 Residential and non-residential Buildings • Alternative, activate for the object type „Building“ the option „Legacy Display“ on the Appearance dialog (on the Options menu, see chapter 9.5) and select on the „Fill“ tab the filling type shown below (3rd in the list): 3 In this case, residential buildings will be displayed with this hatching and non-residential buildings with a vertical hatching. Residents The number of residents is a characteristic of the buildings. The value is displayed as an integer value, despite figures with decimals result when calculating the population density (see chapter 15.4). CadnaA - Reference Manual Chapter 3 - Obstacles 3.1.2 Acoustic Transparency (%) 3.1.2 3 11 Acoustic Transparency (%) The object „Building“ may have a characteristic called „acoustic transparency“ in %. The default value is 0% which means that the building is acoustically non-transparent. 3 This option has been implemented based on user request. Dialog Building, option „acoustic Transparency“ This feature enables to model more or less open structures, e.g., an arrangement of pipes, tanks and other technical equipment penetrated by sound. This is modeled using the object „Building“ with a transparency value addressed. With an acoustic transparency larger than zero it will be considered in the calculation of the screening effect that the object is (partially) transparent. This, however, applies with the calculation procedures VDI 2714/2720 and ISO 9613-2 only. For other calculation procedures and source types Industry, Road, Railway and Aircraft Noise, the option „acoustic transparency“ has no effect unless the propagation model is based on VDI 2714/2720 or ISO 9613-2. Presently (as of 2017), the acoustic transparency has an effect - besides the industrial standards mentioned above - for HJ 2.4 (Industry), Schall03 (2014) and ONR 305011 (both Railway) since they are based on the ISO propagation model. Use acoustic transparency with VDI 2714/2720 and ISO 9613-2 only. CadnaA - Reference Manual Restriction to VDI resp. ISO propagation model 12 3 Calculation Strategy Chapter 3 - Obstacles 3.1.2 Acoustic Transparency (%) The following calculation strategy is applied: • 3 • • • • At first it is checked which objects cause diffraction applying the „ribbon band method“. An acoustic transparency of X% gives a transmission factor of X/100. If the sound energy at the receiver is reduced by dE according to the screening calculation, then with a collective transparency of X% the energy (X/ 100)*dE is added to the sound energy calculated with transparency zero. The total degree of transmission for many buildings in path is the product of all single transmission factors. A building having no transparency or a barrier (i.e transparency is zero) in path will cause a total transparency of zero which means that all buildings are considered non-transparent. The same rule applies to terrain, i.e. a screening terrain contour (explicit or triangulated) in path will also cause a total transparency of zero. At the receiver point two sound contributions are added energetically: • • The first contribution is the diffracted sound over and if necessary around the arrangement and is calculated as for non-transparent objects. The second contribution is calculated as direct sound energy, not taking into account the shielding objects, but multiplying this energy value by the resulting transmission factor defined above. With direct sound contribution Edir and the resulting transmission factor , this second contribution is Edir * . This procedure was implemented due to user demands. It is not described in any standard or guideline. The depth of an object with transparency in ray direction has no impact on the calculation result. The value of the acoustic transparency is considered to be the same for all directions. CadnaA - Reference Manual 3 13 Chapter 3 - Obstacles 3.1.2 Acoustic Transparency (%) Examples The example shows a point source with PWL=100 dB(A), a building and a receiver. There are three variants defined in the file: • variant 1: non-transparent building • variant 2: transparent building (acoustic transparency 10%) • variant 3: without building 03_Obstacles\Transparency\Example 1 - without lateral diffraction.cna 3 The calculations for all three variants without lateral diffraction (option Lateral Diffraction „none“ on tab „Industry“, see e.g. chapter 6.2.9.1 "ISO 9613"). Example 1 - without lateral diffraction, variant 2: building transparent In the three following variants result level is calculated: • variant 1: SPL=40.2 dB(A) • variant 2: SPL=55.0 dB(A) • variant 3: SPL=64.9 dB(A) From the referenced MS-Excel file the calculation procedure can be studied leading to these results applying the strategy described above. CadnaA - Reference Manual 03_Obstacles\Transparency\Calculation Example 1 - without lateral diffraction.xlsx 14 3 03_Obstacles\Transparency\Example 2 - with lateral diffraction.cna Chapter 3 - Obstacles 3.1.2 Acoustic Transparency (%) In this example, the calculations are carried out for all three variants including lateral diffraction (option Lateral Diffraction „some objects“ on tab „Industry“, see e.g. chapter 6.2.9.1 "ISO 9613". 3 Example 2 - with lateral diffraction, variant 2: building transparent For the three following variants the following receiver level are calculated (in variant 2 again with an acoustic transparency of 10%): • variant 1: SPL=45.0 dB(A) • variant 2: SPL=55.3 dB(A) • variant 3: SPL=64.9 dB(A) The level difference between the variants 1 without/with lateral diffraction is 4.8 dB (10 log 3) in this example, since object geometry causes that the lateral path length difference is equal to the path length difference of the direct path across the house. In this case, for the non-transparent building the resulting level with lateral diffraction is 4.8 dB larger than the level without lateral diffraction. 03_Obstacles\Transparency\Calculation Example 2 - with lateral diffraction.xlsx From the referenced MS-Excel file the calculation procedure can be studied leading to these results applying the strategy described above. The above statements apply to grid and facade points analogously. CadnaA - Reference Manual 3 15 Chapter 3 - Obstacles 3.1.2 Acoustic Transparency (%) In real situations, sources may be located within a partially transparent plant or plant sub-structure. For example, valves within bundles of pipes represent point sources which should - in this case - not be shielded by the surrounding partially transparent building. Sources inside of transparent buildings 3 The option „Obstacles within Area Sources do not shield“ (on tab „Industry“, see chapter 6.2.9.1) enables to enter point, line and area sources inside the buildings perimeter. When enabled, the building causes not shielding to sources inside. For sources outside of the buildings perimeter, however, the screening effect is calculated using the specified configuration. Examples option "Obstacles within Area Sources do not shield" active: source inside the (semitransparent) building is not screened. option "Obstacles within Area Sources do not shield" inactive: source inside the building is screened. In this case, the level is also determined by a semi-transparent building due to the transmitted energy. NOTE: With this setting of the configuration option the consistency check in CadnaA indicates that there is a source inside of a building. CadnaA - Reference Manual 16 3 Transparency at Reflections 3 Chapter 3 - Obstacles 3.1.2 Acoustic Transparency (%) An acoustically transparent building causes the same amount of reflections as does a non-transparent building. This means that the transparency effect applies to the diffracted energy, but not to the reflected one. Example Building with no transparency Building with transparency 80%: Level in front of building (source side) remains the same compared to no transparency CadnaA - Reference Manual 3 17 Chapter 3 - Obstacles 3.1.3 Snap Point to Facade 3.1.3 Snap Point to Facade This action on dialog Modify Objects or from the context menu enables to relocate objects (e.g. point, line or area source or receiver point etc.) at a defined distance in front of building facades after they have been inserted. 3 The objects are attached to the facade with the distance defined in the edit box Distance Points-Facade. Distance PointsFacade The operation is applied for all points with a distance smaller than the snap radius. Snap Radius This could be necessary, e.g. • • • after objects have been inserted without activated Object Snap (see chapter 9.3) but shall have a defined distance to the facade in case objects have been placed inside a building, but shall be moved and located at a defined distance from the building‘s facade or when points have been imported from external sources Point Source Area Source vertical House Receiver Initial situation: Building with a point source, a vertical area source and a receiver point. These objects shall be dragged in front of the facade with a distance of 0,05 m. CadnaA - Reference Manual 18 3 Examples\03_Obstacles\SnapePointFacade.cna 3 Chapter 3 - Obstacles 3.1.3 Snap Point to Facade In the shown example objects are located near a building. The receiver point and the vertical area source shall be dragged to the building facade with a distance of 0,05 m. • Click with the right mouse key into the white area of the screen. • Select from the command Modify Objects and the action „Snap Point to Facade“. • Mark the „vert. Area Source“ and the „Receiver“ as shown and confirm with OK. CadnaA - Reference Manual Chapter 3 - Obstacles 3.1.3 Snap Point to Facade 3 19 The receiver point and the vertical area source are snapped to the building‘s facade. 3 With activated options „Copy ID resp. Name“ of building the contents of these fields is copied into the corresponding fields of the objects snapped. Point Source Area Source vertical House Receiver CadnaA - Reference Manual 20 3 Chapter 3 - Obstacles 3.1.3 Snap Point to Facade 3 CadnaA - Reference Manual Chapter 3 - Obstacles 3.1.4 Edit Facades 3.1.4 3 21 Edit Facades The command Edit Facades on the context menu of the object „Building“ enables to edit in the graphics sound sources attached to building facades. In addition, bitmap textures can be assigned to the facades and the roof facilitating the data input and the generation of attractive 3D views. After selecting the command, the dialog Edit Facades is displayed. CadnaA - Reference Manual 3 22 3 Chapter 3 - Obstacles 3.1.4 Edit Facades The dialog consists of a specific toolbar, a status bar and the following views of the selected building: 3 • top: front view of the all facades shown in-plane, • bottom left: top view, • bottom right: isometric view. The scale of the front view can be changed using the toolbar (Zoom in/out, Zoom to Limits). By contrast, the standard of top view and the isometry cannot be changed. Local Coordinate System u, v Coordinated Display of the Mouse Pointer On the status bar, the local coordinates u (increasing to the right) and v (increasing upwards) are displayed in a local coordinate system whose origin (u, v)=(0, 0) is located in the lower left corner of the front view (i.e. the base point of the building’s first polygon-point). When entering objects using the mouse or the keyboard, the object coordinates refer to the local coordinate system (u, v). Note that, by contrast, the source coordinates x, y displayed on dialog Geometry refer to the global coordinate system as already been used by the 2D plan view. The coordinates displayed on the dialogs Facade-Bitmap and RoofBitmap, however, always refer to the local coordinate system (u, v), although the designations „X (m)“ and „Y (m)“ are displayed for software related reasons. When the mouse pointer is moved in the front view, CadnaA shows the corresponding point on both, the top view and the isometric as well. This feature enables to figure out the current cursor position in the uv plane and regarding the height. The input data of the entered objects can be edited by double clicking onto the object’s border. CadnaA - Reference Manual 3 23 Chapter 3 - Obstacles 3.1.4 Edit Facades The following objects and features are available from this toolbar: Select Edit Mode Zoom in Zoom out Zoom to Limits Point Source Line Source vertical Area Source Facade-Bitmap *) Receiver Link to Roof-Bitmap *) Copy to Clipboard Print Toolbar 3 Close Dialog *) These features are available only with the CADNAA option BMP. After having entered a new object the respective edit dialog is accessed in the usual way (double-click on the object’s border while in edit mode, or click with the right mouse button while in input mode). For entered objects, a context menu with the following commands is available (subsequent references refer to the manual „Introduction to CadnaA“): • Edit (see chapter 12.1) • Delete (see chapter 11.1) • Duplicate (see chapter 11.3). Furthermore, all options for graphical editing of objects can also be used with the dialog Edit Facades (see chapter 4.3 in the manual „Introduction to CadnaA“). CadnaA - Reference Manual Context Menu 24 3 Chapter 3 - Obstacles 3.1.4 Edit Facades Edit Objects Point Source 3 Line Source vertical Area Source The same procedures as applied on the 2D-plan are used when defining the geometry of point and line sources in CadnaA (see chapter 4.2.1 and 4.2.2 in the manual „Introduction to CadnaA“). Each source dialog provides the edit boxes as usual (see chapter 2.1.1). When defining vertical surface sources, however, consider that also on the dialog Edit Facades just the upper edge is entered. The vertical extension of vertical surface sources is - as before - entered as a positive distance from the top („z-Extend“) to the bottom of the vertical area source. A conclusive example showing the input of sources is described in chapter 6.1.2 "Editing Facades" of the manual „Introduction to CadnaA“. Receiver Receivers are entered as point objects as conventional. The distance of the receivers from the facade plane is defined on the dialog Object Snap (see chapter 9.3). Insert Bitmap ... for Facades This symbol enables to insert facade bitmaps for texturing each part of the building’s facade separately or, by using just a single bitmap which is repeatedly used for texturing of all facade sections of the building. This feature facilitates the positioning of sound sources on each facade section and, furthermore, offers to generate stunning 3D representations of buildings. Proceed as follows: The subsequent features require the option BMP! • Select the icon „Facade-Bitmap“ from the toolbar. • Drag an area inside a facade section and click with the right mouse button on the border of the bitmap object. Alternatively, change to edit mode and double-click with the left mouse button to open the dialog FacadeBitmap. CadnaA - Reference Manual Chapter 3 - Obstacles 3.1.4 Edit Facades • Edit the bitmap’s coordinates on the dialog Facade-Bitmap (see chapter 10.1.1 "Bitmap Size and Position"). When the real dimensions of the texture are known, enter it’s size starting from the lower left corner at (u, v) = (0, 0). The following additional options are available on the dialog Facade-Bitmap: • Repeat in X (i.e. in u-direction): With this option activated the bitmap addressed to this facade section is repeated in u direction to the edge of the facade section. Repeat on all facades: With this option activated the bitmap will also be used on all other facade sections. • 3 25 Repeat in Y (i.e. in v-direction): With this option activated the bitmap addressed to this facade section is repeated in v direction to the edge of the facade section. The activation of the respective options „Repeat“ and „Repeat on all facades“ is symbolized by arrows on the bitmap edges: Symbols Explanation option „Repeat in X“ activated option „Repeat on all facades“ (in x resp. u direction) activated option „Repeat in Y“ activated CadnaA - Reference Manual 3 26 3 Chapter 3 - Obstacles 3.1.4 Edit Facades The following options are just relevant for display of the facade bitmaps, and even then only when the building‘s height is changed after having assigned facades bitmaps. If the latter is not true, no changes are necessary. When changing the building‘s height subsequently, it has to be decided - with respect to the graphics - as to whether the facade bitmap remains at the previous base point (option „Save Heights relative to Ground of Point 1“) or whether it is moved upwards according to the building‘s new height (option „Save Heights relative to Roof (z) of Point 1“): 3 • Save Heights relative to Ground of Point 1: The vertical alignment of the facade bitmap refers to the height of the building‘s first polygon point. • Save Heights relative to Roof (z) of Point 1: The vertical alignment of the facade bitmap refers to the building height z (building‘s upper edge) at the building‘s first polygon point. Example Default situation: All facades have facades bitmaps assigned. As long as no change of the building‘s height occurs, it is irrelevant which of the two options is selected for the each facades bitmap. When changing, however, the building‘s height (here: height + 5 m) is has to be decided with respect to the graphical representation whether the assigned bitmap remains at the height of building‘s first polygon point (right facade with option „Save Heights relative to Ground of Point 1“) or whether it is moved upwards according to the building‘s new height (left facade with option „Save Heights relative to Roof (z) of Point 1“). CadnaA - Reference Manual 3 27 Chapter 3 - Obstacles 3.1.4 Edit Facades The information regarding the size and the file path of the bitmap/s is stored in text variables of each building. Do not alter the text variables BMPxx (for facades) and BMPROOF (for the roof, see below) as incorrect assignments may result. This symbol enables to insert a roof bitmap for texturing the building’s roof. Proceed as follows: • Select the symbol „Roof-Bitmap“ from the toolbar to open the dialog Roof-Bitmap. • Edit the bitmap’s coordinates on the dialog Roof-Bitmap (see chapter 10.1.1 "Bitmap Size and Position"). When the real dimensions of the texture are known, enter it’s size starting from the lower left corner at (u, v) = (0, 0). The following options are available on the dialog Roof-Bitmap: • Texture Alignment: This option determines how the loaded texture gets aligned on the roof’s surface. Gradient: With this option the texture starts at the highest point of roof surface. This option is useful to apply when the roof ridge is modeled using the object „Barrier“ with the option „Crowing: Roof Edge (3D)“ (see chapter 3.2.2 "Barrier with special crowning"). In this case, the roof texture extends starting from the ridge line to the eaves. Point 1 - Point 2: With this option, the texture starts from the first polygon point of the building, extending from point 1 to point 2 of the building’s polygon. Thus, the texture is arranged parallel to the first polygon part of the building. For non-rectangular shaped buildings the triangulation procedure applied may generate additional triangles on the roof surface which do not comply with the real roof shape. This effect is due to the triangulation procedure and cannot be avoided with non-rectangular shaped buildings. CadnaA - Reference Manual 3 ... for the Roof 28 3 Chapter 3 - Obstacles 3.1.4 Edit Facades Example 1 The texture of a glass facade will be assigned to facade section 1 using the following coordinates: Assigning Facade Bitmaps So, the facades bitmap represents a facade part with a width of 8 m and a height of 6 m, starting in the lower left corner at coordinates (u, v) = (0, 0). Examples\03_Obsta- After activation of all three options („Repeat in X“, „Repeat on all facades“ and „Repeat in Y“) and closing the dialog Facade-Bitmap the texture is displayed on the dialog Edit Facades as shown below. 3 cles\Edit Facades\example 1a.cna CadnaA - Reference Manual Chapter 3 - Obstacles 3.1.4 Edit Facades 3 29 Close the dialog Edit Facades and select the command 3D-Special from the context menu of the building. The texture covers all sections of the facade based on that single texture patch being 8 m wide and 6 m high. 3 3D-Special view with textures on all sections of the façade In addition, a roof bitmap is assigned to the flat roof of the building. The roof bitmap represents a 3 x 3 m wide section of the roof, starting at the first house-point polygon. CadnaA - Reference Manual Assigning a Roof Bitmap 30 3 Examples\03_Obstacles\Edit Facades\example 1b.cna Chapter 3 - Obstacles 3.1.4 Edit Facades Select the option „Point 1 - Point 2“ and close the dialogs. Select the command 3D-Special from the building’s context menu to display the roof covered by the selected texture. 3 3D-Special view with textured facades and flat roof Regarding the use of textures to sloped roofs see chapter 3.1.5 "Defining a Roof Ridge". Example 2 In this example, instead of using a single facades bitmap, different bitmaps are assigned to each of the four facades. It should be noted that the coordinates represent local coordinates u, v. Examples\03_Obstacles\Edit Facades\example 2.cna • Select from the file selector symbol in row „File“ the appropriate bitmap. • Enter on the dialog Facade-Bitmap the real dimensions of the facade section, starting in the lower left corner at coordinates (u, v) = (0, 0). In this example, each facade sections is 21 m wide (in u-direction) and 9.5 m high (in the v-direction). Thus, the following coordinates for the first section are entered: CadnaA - Reference Manual Chapter 3 - Obstacles 3.1.4 Edit Facades 3 31 3 Subsequently, the texture of the first facade section is shown on the dialog Edit Facades: • Now, enter the real dimensions of the second facade section. Since all facade sections have a width of 21 m and a height of 9.5 m, the second section starts at the lower left corner u1=21 m and ends at u2 = 42 m. So, the following coordinates for the second section are entered: CadnaA - Reference Manual 32 3 Chapter 3 - Obstacles 3.1.4 Edit Facades 3 • Continue with the remaining facade sections. • Close the dialog Edit Facades. • Press the key combination CTRL+3 to display the 3D-Special view showing the textured facade. 3D view of a building with a textured facade CadnaA - Reference Manual Chapter 3 - Obstacles 3.1.5 Defining a Roof Ridge 3.1.5 3 33 Defining a Roof Ridge The ridge of building roof can be modeled using the object „Barrier“ with the crowning type „Roof Edge (3D)“ (see chapter 3.2.2 "Barrier with special crowning"). Proceed as follows: • Enter a rectangular building of 10 m height. • Select the object „Barrier“ and draw a barrier in the middle and inside the building’s polygon (or enter the coordinates on dialog Geometry of the barrier). With a barrier representing a roof ridge line and extending to the outside of the building’s polygon, the outside part of the barrier will also cause screening, but this part is not displayed on the 3D-Special view. In the wire-frame view (menu Options|3D-View), however, it is displayed. • Open the dialog Barrier and select the crowning type „Roof Edge (3D)“. • Enter a height of 20 m via the button „Geometry“. • Close the dialog with OK. Building with Barrier, type "Roof Edge (3D)", height 20 m CadnaA - Reference Manual 3 Entering a Roof Ridge as a Barrier 34 3 Chapter 3 - Obstacles 3.1.5 Defining a Roof Ridge • Press the key combination CTRL+3 to display the 3D-Special view. 3 House with screening roof ridge The roof area generated and displayed (in 3D-Special view) using the crowning type „Roof Edge (3D)“ is not a reflecting surface. Reflections at the object „Building“ result - as previously - from the vertical walls of the building only, provided they are reflective and, at least, the first order of reflection is selected (see chapter 6.2.8). Assigning a roof bitmap Now, a texture can be assigned to the roof surface (requires option BMP). Proceed as follows: • Select the command Edit Facades from the context menu of the building. • Select the symbol „Roof-Bitmap“ dialog Roof-Bitmap. • Edit on dialog Roof-Bitmap the bitmap’s coordinates (see chapter 10.1.1). When the real dimensions of the texture are known, enter those values starting from the lower left corner at (u, v)= 0, 0). • On option „Texture Alignment“ select the option „Gradient“ in order to align the texture starting from the highest point of the roof (i.e. the ridge). • Close the dialogs Roof-Bitmap and Edit Facades. from the toolbar to open the CadnaA - Reference Manual 3 35 Chapter 3 - Obstacles 3.1.5 Defining a Roof Ridge • Press the key combination CTRL+3 to display the 3D-Special view. 3 Building with pitched roof and roof texture The roof texture is also used for the gable walls of the building. However, the eave edge is not a screening edge, only shown in the 3D-Special view. In the following an additional gable wall is entered. Starting with a building having a roof edge already proceed as follows: • Activate while in edit mode the building’s polygon using the left mouse button. • Hold down the CTRL key and click at the two locations of the building’s polygon intersecting with the (imaginary) extension of the ridge line. This will insert two additional polygon points. • Open the dialog Geometry of the building. • Select the option „Height at every Point“ and enter for the additional points - for example - a height of 20 m. CadnaA - Reference Manual Defining gable walls 36 3 Chapter 3 - Obstacles 3.1.5 Defining a Roof Ridge Alternatively, you may of course enter all the coordinates x, y, z on the dialogue Geometry directly. 3 Entering the height of the gable wall • Close the dialog with OK. • Press the key combination CTRL+3 to display the 3D-Special view. Building with gable walls, roof ridge and roof texture In this case, both, the roof ridge and the eaves edges cause screening. CadnaA - Reference Manual 3 37 Chapter 3 - Obstacles 3.1.5 Defining a Roof Ridge In addition to the pitched roof shown in the previous example more roof shapes are possible, such as hipped, gambrel roof or tent shape. Other Roof Shapes 3 Roof shapes (barriers are dotted lines): top-left: mansard roof, -right: tent (with option „absolute Height at every Point“) bottom-left: gable roof, -right: hip roof 3-Special view of several roof shapes CadnaA - Reference Manual 38 3 Chapter 3 - Obstacles 3.1.5 Defining a Roof Ridge 3 CadnaA - Reference Manual 3 39 Chapter 3 - Obstacles 3.1.6 Generate Building 3.1.6 Generate Building The command Generate Building is available from the context menu of the area source. This command generates a building of a defined height with all facades and the roof covered with area sources (by default at a distance of 0.05 m off the facade). All sources will receive the same emission data as specified for the original area source where the vertical area source get addressed a directivity index of K0=3 dB by default. • First, insert a area source in the shape of the horizontal projection of the building. • Switch to the edit mode and double-click the area source. This opens the edit dialog. • Activate the Sound Reduction option and enter an indoor level, either directly or with reference to a spectrum. Enter all further parameters for this source, and click OK to close the dialog. • Then click the area source with the right mouse button and select Generate Building from the context menu. 3 In the Generate Building dialog, you can enter the parameters for the height of the building and, if required, the height of the terrain at the base of the building, and an absorption coefficient - either a single-number value or a reference to a spectrum (see chapter 12.1 Local and Global Libraries). • Height of building relative (m): relative building height > 0 m • Height of ground absolute (m): After activation the absolute ground height at the location of the building polygon can be specified. The entered ground height effects the shape of the terrain depending on the settings on the "DTM" tab. CadnaA - Reference Manual Dialog Options 40 3 Chapter 3 - Obstacles 3.1.6 Generate Building • 3 Absorption: After activation the absorption coefficient can be entered numerically or a spectrum can be selected via the file selector symbol from local or global absorption library. After selection of an absorption spectrum the spectrum's ID code is displayed on this box. When all boxes are completed close the dialog by OK. CadnaA generates • a building with a specified height – 10 m in this example, • the appropriate number of vertical area sources whose parameters are adopted from the first area source, at a distance of 0.05 m in front of the facades, • a horizontal area source at 0.05 m above the roof and • (in case) a surrounding contour line (see chapter 4.1.1) with the absolute height as entered. CadnaA - Reference Manual Chapter 3 - Obstacles 3.2 Barrier 3.2 3 41 Barrier The calculation of the screening effect is based on the standard or guideline selected for each noise type (see chapter 6.2.1). The available calculation options consequently depend on this selection as well. Information on the handling of barriers by a standard or guideline can be found in the following chapters: • Industry: see chapter 2.1 • Street: see chapter 2.4 • Rail: see chapter 2.6 Reflections at the surfaces of a barrier are taken into account according to the image source method if 1. a order of reflection > 0 is selected (see chapter 6.2.8) and if 2. the barrier is defined as reflecting by entering a reflection loss or, alternatively, an absorption coefficient. Depending on the selected standard or guideline additional conditions may apply to generate a reflection at a barrier (or at any other possibly reflecting obstacle), for example a minimum size/dimension in relation to the wavelength. CadnaA - Reference Manual 3 42 3 Chapter 3 - Obstacles 3.2 Barrier 3 Dialog Options Name, Memo-Window, ID, ObjectTree see chapter 4.4.2 in the manual "Introduction to CadnaA" option „No Reflection“ This is the default setting. In this case, no reflected rays are generated, even when a reflection order larger than zero is selected. Reflection Loss/ Absorption Coeff. Alpha Either the reflection loss or the absorption coefficient Alpha can be entered, for each side separately. The specification „left“ or „right“ is based on the viewing direction from first to last polygon point. Via the respective file selector symbols either a reflection type (according to RLS-90 /17/) or an absorption spectrum from the local or the global (by SHIFT-clicking) library of absorptions can be selected. Floating Barrier see chapter 3.2.1 Crowning see chapter 3.2.2 see also: chapter 3.2.3 "Barrier with transmission" see also: chapter 3.8.1 "Automatically Optimize Noise Barriers" CadnaA - Reference Manual 3 43 Chapter 3 - Obstacles 3.2.1 Floating Barrier 3.2.1 Floating Barrier The floating barrier is a special object which is not described in the existing standards or guidelines for calculating the sound propagation outdoors. Originally, it has been designed to be used for modeling barriers on bridges (see chapter 3.3). 3 Due to further development of CadnaA this application is obsolete meanwhile because barriers on bridges or viaducts can be modeled more comfortably by using the option „Self-Screening“ of roads (see chapter 2.4.1) and railways (see chapter 2.6.1). Nevertheless, the floating barrier can be used to model - for example elevated components in a plant (e.g. elevated horizontal or vertical tanks or containers). If this option is enabled, then the lower edge of the barrier is above the ground level. Thus, this barrier is no longer attached to the ground. Option "Floating Barrier" In this input box - in addition to the geometry defined on the Geometry dialog - the vertical extent from the top edge to the bottom edge of the floating barrier is entered. Z-Extent (m) With a barrier height (upper edge) of 10 m relative and as a Z-extent of 3 m the height of the barrier’s lower edge is 7 m above ground. Example CadnaA - Reference Manual 44 3 Properties of the floating barrier Chapter 3 - Obstacles 3.2.1 Floating Barrier A floating barrier with the lower edge lifted from the ground has the following properties: 1. The screening effect is calculated - depending on the selected standard/ guideline - for each ray hitting the barrier surface, considering all three propagation paths (diffraction across the top edge and laterally around the barrier). 2. Rays passing underneath the barrier’s lower edge are not attenuated (i.e. free propagation). 3. A diffraction effect around the bottom edge is not taken into account. The diffraction algorithms found in the present standards and guidelines normally just hold for a barrier’s upper edge standing vertically on the ground. The diffraction around the lower edge cannot be calculated using these algorithms, as the more complex interaction with the ground is not included. Since a diffraction model is missing in the standards, CadnaA does neither consider a diffraction effect. 4. Reflections of rays hitting the barrier’s surface are calculated according to the image source method. 3 Barrier on a Bridge The procedure described below when entering a barrier on road or railway bridges is superfluous by using the option „Self-Screening“ provided for the object types „Road“ and „Railway“ (see chapter 2.4.1 and 2.6.1, for both in section "Self-Screening"). When a barrier is located on a bridge, the height of the barrier section on the bridge must be entered either by entering • the height of the top edge above the base plate of the bridge, and the „Building Height“ button in the Geometry dialog must be activated that means 3 m in our example - and the same value must be entered for the z dimension after „Floating Barrier“ has been activated, or CadnaA - Reference Manual 3 45 Chapter 3 - Obstacles 3.2.1 Floating Barrier • the height of the top edge as an absolute value (13 m in the example. The z dimension remains the same (3 m). In both cases, further polygon points must be inserted for the barrier where it intersects contour lines. 3 The barrier is calculated correctly in both cases. 10-m contour line Bridge 2 additional polygon points Interpolate height of contour line first point 10 m, last point 0 m First point Barrier on bridge 0-m contour line Inserting a barrier on a bridge • In the two dialogs below enter the height of a reflecting barrier as 3 m above bridge level. 3-m-high barrier on a bridge in the 3-D front view Activate Floating Barrier in the edit dialog CadnaA - Reference Manual Specify the barrier height above the bridge by selecting the „Roof“ option. Examples\03_Obstacles\Bridge.cna 46 3 Chapter 3 - Obstacles 3.2.1 Floating Barrier The vertical grid shows the level distribution due to the reflection at the barrier (in the upper right half sphere) and the screening effect caused by the barrier on the left side of the bridge. 3 Sound level distribution on a vertical grid for a road on a bridge with a floating barrier see also: chapter 2.4.1 "Common Input Data", section "Self-Screening" CadnaA - Reference Manual 3 47 Chapter 3 - Obstacles 3.2.2 Barrier with special crowning 3.2.2 Barrier with special crowning Barriers having a special crowning can be edited and calculated in CadnaA, depending on the calculation standard selected. In this case, select the desired crowning from the list box „Crowning“ on dialog Barrier. 3 Option „Crowning“ • normal: models a vertical screen with no crowning • Cantilever to the left/right: The designation „left“ or „right“ refer to a viewing direction from first to last polygon point of the barrier. Enter the horizontal and vertical extent of the cantilever (in m). The location of the cantilevered part is displayed in the graphics by a dashed line. • At the cantilevered surface is no reflection is calculated. So, the cantilever is assumed to be fully absorbing. With a single barrier, the level calculated with sources below and outside the cantilevered part is valid. T-shaped (only available with option MITHRA or NMPB08): Enter the dimensions (in meters) of the T part perpendicular to the surface (permissible value range 0.85 to 1.50 m). CadnaA - Reference Manual 48 3 Chapter 3 - Obstacles 3.2.2 Barrier with special crowning • 3 • Button "Geometry" Cylindric (only available option MITHRA or NMPB08): Enter the diameter (in m) of the cylinder (permissible value range 0.60 to 1.00 m). In CadnaA, the Mithra barrier crownings are considered only: - with NMPB 08 (Industry, Road, Fer), whether Mithra option is on or off (see chapter 6.2.2) - with Mithra option activated (and hence Angle Scanning, see chapter 6.2.2): for every standard being selected. Roof Edge (3D): When barriers are modeled inside buildings this option caused the building polygon to be generated by triangulation using the barrier’s and the building’s height. In this case, just the roof ridge modeled by the barrier causes screening, but not the triangulated roof edges (see chapter 3.1.5). Via the button „Geometry“ the barrier’s height is specified (see chapter 4.2). Additional Information Crowning "Normal" The type „(normal)“ is applicable to all kinds of calculation methods. The polygon describing the barrier is considered in the calculation of the screening effect. The diffraction algorithm according to calculation method selected is applied. Crowning with Cantilever Whether the option „Cantilever top the left/right“ is applicable depends on the calculation method selected. The following chapters contain related information: • • • Guidelines for Input Industry: see chapter 6.2.9 Road: see chapter 6.2.10 Railway: see chapter 6.2.11 Enter a value for the horizontal and vertical part of the cantilever. The height of the barrier displayed on the dialog Geometry is the height of the diffracting edge at vertical, plane barriers. CadnaA - Reference Manual Chapter 3 - Obstacles 3.2.2 Barrier with special crowning 3 49 By selecting "left" or "right" the cantilever directs into this direction when looking from the first to the last polygon point. The cantilevered part is displayed using a dashed line. As an example, the barrier height is 6 m (on dialog Geometry), and the cantilever horizontal and vertical 1 m results in the following figure. Barrier with cantilever displayed in 3D front view Barrier with cantilever in 3D-Special view CadnaA - Reference Manual 3 50 3 Crowning „T-shaped“ Chapter 3 - Obstacles 3.2.2 Barrier with special crowning Barriers with crowning attribute „T-shaped“ are valid for all calculation methods with "Mithra-compatibility" activated. The value for the width has to be between 0.85 and 1.5 m. The T-shaped crowning is created symmetrically on top of the barrier, with half the width on either side (is shown in 3D-Special). 3 Crowning „Cylindric“ Barriers with crowing „Cylindric“ are valid for all calculation methods with "Mithra-compatibility" checked. After entering a value for the diameter between 0.60 and 1.00 m a cylindric crowning is created with the upper centre line of the barrier (is shown in 3DSpecial). Crowning „Roof Edge (3D)" The triangulation of the roof surface inside a building’s polygon occurs just for barriers having the option „Roof Edge (3D)“ selected. This enables to model real roof structures, also for display in the 3D-Special view providing a screening effect (see chapter 3.1.5 "Defining a Roof Ridge"). When modeling a roof ridge, however, this option does not generate gable walls raising up to the roof ridge. In order to enter a gable wall up to ridge height, additional points making up the building polygon are required (at the intersections between roof and exterior wall). In this case, use the option „Height at every Point“ from dialog Geometry of the building (see chapter 3.1.5 "Defining a Roof Ridge"). CadnaA - Reference Manual 3 51 Chapter 3 - Obstacles 3.2.2 Barrier with special crowning With regard to the practical application of barriers with cantilever the following situations apply: • source below the cantilever, • source outside of the cantilever. In order to calculate these situations correctly, the shortest ray path must be found starting from the source around the cantilever’s edge to the receiver point. The method applied will retrieve the shortest path difference for a single barrier in the entire space. Regardless of the receiver point’s location, one or two diffracting edges are taken into account. As mentioned already, the sloping surface of the cantilever is considered to be full absorbing. This feature enables to model porches or galleries alongside of roads with their lower surfaces being absorbing. Example: point source and barrier with cantilever Vertical Grid: point source directly below the cantilever’s edge Vertical Grid: point source below the cantilever (Dz without limit) CadnaA - Reference Manual Application Notes for Cantilever 3 Source below the cantilever 52 3 Source outside the cantilever Chapter 3 - Obstacles 3.2.2 Barrier with special crowning The same procedure is applied with sources below the cantilevered part. The levels are valid for single barriers within the entire space. 3 Vertical Grid: point source outside of the cantilever CadnaA - Reference Manual 3 53 Chapter 3 - Obstacles 3.2.3 Barrier with transmission 3.2.3 Barrier with transmission All calculation standards for the sound propagation outdoors treat the screening at obstacles (e.g. at barriers) not accounting for sound transmission through the obstacle. With this approach it is implicitly assumed that the screening effect (possibly including lateral diffraction) is the dominating effect when calculating the sound propagation. In order to ensure that this requirement is met, several calculation standards specify a lower limit of the surface mass or a minimum (weighted) sound reduction index (transmission loss or STC) of the screening obstacle. For example, ISO 9613-2, section 7.4, states /8/: 3 Validity of diffraction equations „An object shall be taken into account as a screening obstacle (...) if it meets the following requirements: the surface density is at least 10 kg/m²; the object has a closed surface without large cracks or gaps ... Each object that fulfills these requirements shall be represented by a barrier with vertical edges. ...“ Considering the transmitted energy through the barrier requires that the weighted sound reduction index Rw (or STC) or the sound reduction spectrum (transmission loss spectrum) of the barrier is available. Proceed as follows to model a barrier with a finite transmission: • Activate the object snap on dialog Options|Object Snap with a „Distance Points-Facade“ of 0.05 m (default value). • Place a receiver in the middle of the barrier on the sound source side. CadnaA - Reference Manual Considering a finite sound transmission 54 3 Chapter 3 - Obstacles 3.2.3 Barrier with transmission • 3 When the barrier has reflective properties, make sure that in the configurations, „Reflection“ tab, a „Min. Distance Receiver-Reflector“ of 1.00 m and a „Min. Distance Source - Reflector“ of 0.10 m is specified (see chapter 6.2.8). In conjunction with the setting for the ObjectSnap, these standard configuration settings ensure that the level calculated at the receivers does not include any reflection component (thus, being the free field level) and that the sound power radiated by the vertical area source does not include any reflection component from ray-tracing (i.e. the reflection is considered by the directivity index K0=3 dB on the source dialog, see chapter 2.1.1, section "K0 without Ground"). • Calculate the receiver level, either as an A-weighted single value or as a spectrum. • Enter on the far side of the barrier (as seen from the source) a vertical area source (see chapter 2.1). Apply the command Parallel Object from the barrier‘s context menu (entering a distance of 0.05 m, a height difference of 0 m, and a Z-extend of 8 m corresponding to the barrier‘s height). The directivity index „K0 w/o ground“ of 3 dB is maintained as the source radiates into half sphere (i.e. not considering the ground reflection here). • The emission of the vertical area source results from the receiver level on the source side and from the sound reduction index (or STC) of the barrier: when the receiver level on the source-side is an A-weighted level: SPLi = SPLsource side + 4 dB when the receiver level on the source-side is a spectrum: SPLi (f) = SPLsource side (f) + 6 dB (in each frequency band). This numerical approach for the calculation of the interior levels compensates for the procedure used in the VDI guideline 2571 /37/ (see chapter 2.1.1, section "Transmission Loss"). CadnaA - Reference Manual Chapter 3 - Obstacles 3.2.3 Barrier with transmission • Activate the option „TransLoss“ on the dialog vert. Area Source and enter into the box „Interior Level“ the value SPLi as determined or establish a reference to a sound level spectrum (after having entered spectrum via the menu Tables|Libraries (local)|Sound Levels). • Enter the weighted sound reduction index or establish a reference to a transmission loss spectrum (after having entered spectrum via the menu Tables|Libraries (local)|Sound Reduction Indeces). • Restart the calculation. Now, the resulting levels contain the transmitted energy fraction. Note that the procedure described above is an approximation making use of some assumptions. For example, this approach assumes a uniform sound distribution on the source-side of the barrier. Moreover, it is no taken into account that the sound reduction (transmission loss) may depend on the angle of the inciding sound. CadnaA - Reference Manual 3 55 3 56 3 Example 1: Procedure with A-weighted levels Chapter 3 - Obstacles 3.2.3 Barrier with transmission The example file shows the following arrangement of objects (here for variant 2 „with Transmission“) 3 ... with the following input data for the vertical area source when calculating using weighted data (A-weighted interior level and sound reduction index, Rw (STC) = 10 dB): Examples\03_Obstacles\Barrier with Transmission\example 1 barrier transmission using A-weighted level.cna Toggle variants „without transmission“ and „with transmission“ in order to assess the influence of the transmission in this example. In this example, the non-spectral ground attenuation according to ISO 9613-2, section 7.3.2, is used /8/. CadnaA - Reference Manual 3 57 Chapter 3 - Obstacles 3.2.3 Barrier with transmission The sample file shows the arrangement of objects (again for variant 2 „with Transmission“) Example 2: Procedure using spectra 3 ... with the following input data for the vertical area source for invoice with spectral data (spectral indoor level and spectral transmission loss): Toggle variants „without transmission“ and „with transmission“ in order to assess the influence of the transmission in this example. In this example, the spectral ground attenuation according to ISO 96132, section 7.3.1, is used /8/. CadnaA - Reference Manual Examples\03_Obstacles\Barrier with Transmission\example 2 barrier transmission using spectrum.cna 58 3 Chapter 3 - Obstacles 3.2.3 Barrier with transmission 3 CadnaA - Reference Manual 3 59 Chapter 3 - Obstacles 3.2.4 Barrier staggered in height 3.2.4 Barrier staggered in height The calculation procedures for sound propagation outdoors do not cover barriers with sections staggered in height and having different absorptive properties. Screens (and all other types of obstacles) always have a uniform reflection loss or absorption coefficient on each barrier side. 3 Due to the practical relevance of such a barrier design, the recommended procedure in CadnaA is described below. A barriers with sections staggered in height is modeled by two distinct barriers, the base line of which are close to each other (e.g., at a distance of 0.10 m). To this end, the barrier having a higher absorption coefficient (larger reflection loss) is facing away from the source, while the barrier having a smaller absorption coefficient (smaller reflection loss) is placed on the source-facing side. Example 1: barrier with an absorbing lower part and a reflective upper part (modeled from two barriers, vertical cross section): Examples Examples\03_Obstacles\Barrier - staggered\example 1 - lower part absorb - upper part reflect.cna In the 3D-Special view the sound rays are represented as line sources having no emission (resulting from converting the rays being auxiliary polygons). CadnaA - Reference Manual 60 3 Examples\03_Obstacles\Barrier - staggered\example 2 - lower part reflect - upper part absorb.cna Chapter 3 - Obstacles 3.2.4 Barrier staggered in height Example 2: barrier with a reflective lower part and an absorbing upper part (modeled from two barriers, vertical cross section): 3 Limitations In the same way, barriers can be modeled consisting of several sections having different absorption. The reflected ray paths, generated based on the heights of the source and the reflecting obstacles, hit either the absorbing or the reflecting region of the staggered barrier. Consequently, in a specific geometrical situation, the noise increasing effect may not occur and at each receiver point. In this example (vertical cross section), there are two receivers on a facade at which reflections of 1st order occur at a barrier with sections staggered in height. The level at the upper receiver is includes the reflection loss of the rear, absorbing barrier, while the level at the lower receiver includes the reflection loss of the reflecting barrier in front. CadnaA - Reference Manual Chapter 3 - Obstacles 3.3 Bridge 3.3 3 61 Bridge The object "bridge" represents a horizontal plate causing diffraction from sources located below or above. This object was the only way in former releases of CadnaA to model a screening plate lifted above the ground. Due to the option „Self-Screening“ of the objects „Road“ and „Railway“ the object „Bridge“ became dispensable for modeling of bridge plates (see section „Self-screening“ of roads, chapter 2.4, and of railways, chapter 2.6). The object „Bridge“ has the following properties: • The bridge is a horizontal plate being a closed polygon. All sound rays not intersecting the bridge remain unaffected. • When a sound ray by a source lies above the bridge plate intersects the plate the diffraction is calculated for receiver points not directly below the bridge’s plate. • For sound rays from sources lying below the bridge intersecting the plate to receiver points above the bridge the diffraction is calculated due to the bridge’s edge. • Diffraction into the space below the bridge is not considered. Therefore, resulting levels below the bridge are irrelevant! • The bridge plate is assumed to have a plane surface being parallel to the reference plane regardless of the terrain’s contour. • The height of the bridge is always taken from the first polygon point (dialog Bridge|Geometry). Heights entered for further polygon points are not relevant. CadnaA - Reference Manual 3 62 3 3 Chapter 3 - Obstacles 3.3 Bridge • The bridge plate is considered as if it were a building’s roof. When the bridge’s height attribute is set to „Roof“ (dialog Bridge|Geometry) the height above the bridge’s level is entered. • On the vertical grid or on the cross section the bridge plate is not displayed. The sound diffracted downwards from roads or railway lines on top of the bridge are calculated correctly considering the diffraction around the bridge’s edges. Rays passing below the bridge causing an immission on the opposite side are considered automatically. Due to the „floating barrier“-option even barriers on a bridge can be modeled (see chapter 3.2.1 "Floating Barrier"). Examples see also directory “Examples\03_Obstacles\Bridge“ CadnaA - Reference Manual 3 63 Chapter 3 - Obstacles 3.4 Ground Absorption Areas 3.4 Ground Absorption Areas The object „ground absorption“ causes an attenuation • if the selected standard or guideline (see chapter 6.2.1 "Country Tab") applies the ground factor G (originally used by VDI 2714 /38/ and ISO 9613-2 /8/), • or a different parameter is used to specify the dampening effect of the ground which can be transferred into an appropriate value of the ground factor G. • When a standard or guideline includes several, different ground attenuation models a further selection on the relevant configuration tab for the a specific source type may be required (e.g. see chapter 6.2.9.1 "ISO 9613"). 3 For more information regarding the guideline-specific procedures for calculating ground attenuation see chapter 6.2.9 "Industry Tab", chapter 6.2.10 "Road Tab", and chapter 6.2.11 "Railroad Tab". In case the selected standard or guideline applies a generalized ground attenuation model - i.e. the ground attenuation does not depend on the local ground properties, but is just determined from the ray‘s geometry - the object „ground absorption“ does not cause any damping effect. Dialog Options see chapter 4.4.2 in the manual "Introduction to CadnaA" Name, Memo-Window, ID, ObjectTree value of the ground factor G (accord. to ISO 9613-2), default value G=0 Ground Absorption G CadnaA - Reference Manual 64 3 Object‘s Geometry Chapter 3 - Obstacles 3.4 Ground Absorption Areas The object is entered as a closed polygon with the height specified - if any on the dialog Polygon: Geometry is not relevant. With multiple ground absorption areas overlapping each other, the area on top represents the overlap region. This is equal to a lower position of the respective absorption area in the table Ground Absorption (see Tables| Obstacles menu). 3 Special Case: Road & Rail In conjunction with the self-screening option for the objects „Road“ and „Railway“ an additional width can be entered specifying the ground absorptive properties within the road or railway track area (see chapter 2.4.1 and 2.6.1, both section "Only for Ground Absorption, no Screening"). „Ground Absorption“ tab see Calculation|Configuration menu, „Ground Absorption“ tab (see chapter 6.2.7) Default Ground Absorption This value specifies the ground factor G for areas not covered by the object „Ground Absorption“ (default value 1, range 0<=G<=1). Option „Use Map of Ground Absorption“ This option enables - in case numerous ground absorption areas - to reduce the calculation time by generating a map of ground absorption areas. CadnaA - Reference Manual 3 65 Chapter 3 - Obstacles 3.5 Built-Up Areas and Foliage 3.5 Built-Up Areas and Foliage Built-up areas are defined by a closed polygon and by its height (on dialog Geometry). The resulting attenuation due to built-up areas depends on the guideline selected for the respective type of source. Built-Up Areas 3 With calculation according to VDI 2714 or ISO 9613-2 the attenuation due to built-up areas is taken into account for areas as defined. When calculating traffic noise with the setting „strictly according to RLS-90“ or „strictly according to Schall03“, however, no attenuation occurs with built-up areas (tabs Road“ and „Railroad“ on dialog Calculation|Configuration). Dialog Built-Up Area According to VDI-guideline 2714, section 6.4.2, the attenuation by built-up areas DG for single sources and for propagation through scattered buildings (i.e. no extending building facades): DG = (m * B * sG - DBM) dB 0 dB where m: average reciprocal length of edges in 1/m B: area coverage (of buildings) in % sG: length of sound path through the built-up area in m (for this reason the height of the object „Built-Up Area“ is relevant) DBM: attenuation due ground & meteorology in dB With single buildings the average reciprocal length of edges is 0.1 m-1 at maximum. With scattered halls smaller values for m apply. CadnaA - Reference Manual Calculation according to VDI 2714 66 3 Chapter 3 - Obstacles 3.5 Built-Up Areas and Foliage The length of sound ray sG through the built-up area is evaluated for a curve radius of 5000 m from source to receiver. Enter the average height of buildings with the area in dialog Built-Up Area|Geometry. According to VDI-guideline 2714 the sum DBM+DD+DG is limited to a maximum value of 15 dB (DD: attenuation due to foliage). 3 The application of the object Built-Up Area is useful where the geometry of individual objects is not available. Otherwise, the object Building should be used. Calculation according to ISO 9613-2 According to ISO 9613-2, annex A.3, the attenuation due to housing AHous,1 results from: AHous,1 = 0.1 * B * dB dB where: - B: area coverage in % - dB: length of sound path through the built-up area in m The attenuation due to housing AHous,1 is limited to 10 dB according to ISO 9613-2. The sum of attenuations Agr+Afol+Ahous, however, is not limited to 15 dB - compared with VDI 2714. Using a text block with the name OLD_OPT_CALC this limitation can be engaged (text to be entered: iso_asum_15db_x125=1). The contribution of AHous,2 according to ISO 9613-2, annex A.3, is not considered by CadnaA. CadnaA - Reference Manual 3 67 Chapter 3 - Obstacles 3.5 Built-Up Areas and Foliage Dense woods („foliage“) are defined by a closed polygon and by its height (on dialog Geometry). The resulting attenuation due to foliage depends on the guideline selected. In the following, the procedures according to VDI 2714, ISO 9613-2, and Schall 03 (1990) are explained. Foliage According to VDI-guideline 2714, section 6.4.2, the attenuation due to foliage DD calculates from: Calculation according to VDI 2714 for A-weighted levels: DD 0.05 dB / m sD for spectra: 1 / 3§ f DD 0.006 dB / m s D Hz with sD: length of sound path through the foliage in m. The length of sound ray sD through the foliage is evaluated for a curve radius of 5000 m from source to receiver. Enter the average height of buildings with the area in dialog Foliage|Geometry. The resulting attenuation just holds for permanent (leaves!) and dense woods (i.e. with dense undergrowth). According to VDI-guideline 2714 the sum DBM+DD+DG is limited to a maximum value of 15 dB (DG: attenuation by built-up areas). According to ISO 9613-2, annex A.2, attenuation due to foliage calculates from: Afol = Df * df with df: length of sound path through the foliage in m. with the attenuation Df as shown in the next table: CadnaA - Reference Manual Calculation according to ISO 9613-2 3 68 3 3 Chapter 3 - Obstacles 3.5 Built-Up Areas and Foliage path length df (m) octave band center frequency (Hz) 63 125 250 500 1k 2k 4k 8k 10 <= df <= 20 attenuation (dB) 0 0 1 1 1 1 2 3 20 <= df <= 200 attenuation (dB/m) 0,02 0,03 0,04 0,05 0,06 0,08 0,09 0,12 Calculation according to Schall03 (1990) The attenuation by built-up areas DG is not limited by ISO 9613-2. The procedure corresponds with the calculation in guideline VDI 2714 for A-weighted levels. When performing road noise calculation with setting „strictly according to RLS-90“ no attenuation due to foliage is considered. Calculation according to Schall03 (2014) The attenuation due to foliage is not considered (see section 6.1 in /26/). CadnaA - Reference Manual 3 69 Chapter 3 - Obstacles 3.6 Cylinder 3.6 Cylinder The cylinder is screening object raising vertically from the ground. The cylinder may have a reflective properties. When entering a cylinder using the mouse, first click to it’s center point and then define the radius. 3 Line source Immission point Source Reflecting cylilnder Screening at a circular cylinder Reflections at a circular cylinder By default, cylinders - as with the object „Building“ (see chapter 3.1) - are modeled without a roof plate, although this is displayed in the 3D-Special view (see chapter 9.14). For sources above roof level the ground attenuation results from the source height above ground and not above roof (as the roof is not a reflecting surface). see chapter 3.1, section "Internal Sources" When modeling the radiation by cylindrical buildings it is recommend to convert the cylinder first into the object „Building“ (see chapter 11.13, manual „Introduction to CadnaA“) and then to apply the command/ action „Parallel Object“ (see chapter 11.19, manual „Introduction to CadnaA“) is a vertical circumferential surface source. CadnaA - Reference Manual Internal Sources 70 3 Chapter 3 - Obstacles 3.6 Cylinder Dialog Options 3 Dialog Cylinder BEZ, Memo-Window, ID, ObjectTree see chapter 4.4.2 in the manual "Introduction to CadnaA" Reflection Loss/ Absorption Coeff. Alpha By default, cylinders are not reflecting sound (option „No Reflection“). Selecting one of the options „Reflection Loss“ or „Absorption Coefficient Alpha“ enables to specify via the respective file selector symbol either a reflection type (according to RLS-90 /17/) or to address an absorption spectrum from the local or the global (by SHIFT-clicking) library of absorptions. In this case, reflections from the cylinder’s surface are taken into account up to the first order of reflection applying the image source method, provided that on tab „Reflection“ (see chapter 6.2.8) in the configuration of calculation at least the first order of reflection is selected. Button "Geometry" Via the button „Geometry“ the cylinder’s height is specified (see chapter 4.2). Examples\03_Obstacles\Cylinder - abs Height - Input of Ground Height.cna Sources in Cylinders do not shield The option „Sources in Buildings/Cylinders do not shield“ is available for industrial sources (see chapter 6.2.9 "Industry Tab"). When entering the absolute height and the ground height using a value above the actual ground level the same restrictions specified in chapter 3.1 "Building", section "Button "Geometry"" hold for cylinders as well. CadnaA - Reference Manual Chapter 3 - Obstacles 3.7 3D-Reflector 3.7 3 71 3D-Reflector The object „3D-Reflector“ is a special object not described by any standard or guideline with respect to its properties and its screening effect. 3 Inclined, floating 3D reflector in the 3D view The 3D-reflector models a freely orientated, arbitrarily shaped closed and plane polygon area, where the shortest path difference between source and receiver determines the screening effect. In addition, lateral diffraction and reflections up to the 1st order are taken into account. Distinct edges of 3Dreflector can be excluded from the calculation of lateral diffraction (see below „Exclude Edges“). This prevents for diffracting around the selected edge, for example, at geometrically adjacent obstacles. The reflector surface must form a flat surface. When polygon points are not in a plane, a plane surface is generated by quadratic averaging. In these cases, the reflector surface is still displayed as being defined originally by the suer (for example, for display on the 3D special view). CadnaA - Reference Manual 72 3 Normative References 3 Chapter 3 - Obstacles 3.7 3D-Reflector The 3D-reflector as a special object is just compatible with such standards and guidelines, using a diffraction model evaluating the path difference based on path geometry only. Therefore, the 3D-reflector shows no effect with standards and guidelines (i.e. no screening) which are based on a diffraction model using, for example, an additional height h or which exclude certain obstacles in the ray path from the diffraction calculation (e.g. „the most efficient barrier“ etc.). By default, the 3D-reflector is, therefore, just compatible with the following standards and guidelines whose diffraction models comply with the above conditions and where the screening effect by multiple obstacles in the ray path is evaluated by applying so-called „rubber-band-method“: • ISO 9613-2 • RLS-90 • Schall 03 (1990) and Schall 03 (2014) For more information on guidelines-specific procedures for assessing diffraction and on the effectiveness of the effectiveness of 3D-reflector see chapter 6.2.9 "Industry Tab", chapter 6.2.10 "Road Tab", and chapter 6.2.11 "Railroad Tab". Configuration of Calculation The configuration settings on tabs „Industry“, „Road“ and „Railway“ are also relevant when calculating diffraction of the 3D reflector. Please note in special: • For the German procedures „RLS-90“ (road) and „Schall 03“ (railway) the exclusion of the lateral diffraction and the suppression of the ground attenuation is strictly regulated (option „Strictly acc. to ...“). • For industrial sources, the lateral diffraction can be accounted for or not and the screen coefficients may be modified if necessary (see chapter 6.2.9 "Industry Tab"). CadnaA - Reference Manual 3 73 Chapter 3 - Obstacles 3.7 3D-Reflector Dialog Options 3 see chapter 4.4.2 in the manual "Introduction to CadnaA" Name, Memo-Window, ID, ObjectTree By default, the 3D-reflector does not reflect sound (option „No Reflection“). Selecting one of the options „Reflection Loss“ or „Absorption Coefficient Reflection Loss/ Absorption Coeff. Alpha Alpha“ enables to specify via the respective selector symbol either a reflection type (according to RLS-90 /17/) or to address an absorption spectrum from the local or the global (by SHIFT-clicking) library of absorptions. In this case, reflections from the reflector’s surface are taken into account applying the image source method, provided that on tab „Reflection“ (see chapter 6.2.8) in the configuration of calculation at least the first order of reflection is selected. Regard the definition of „left“ and „right“ reflector side „right-hand-rule“ applies: Suppose the right hand being curved along the outer edge of the polygon, the fingers pointing from the first to last point, the stretched thumb points into normal direction of the „right“ side. Left/Right Side On the dialog Exclude Edges (see below) the reflector‘s edges can be marked not to be taken into account in the calculation of diffraction. Up to 32 edges of the 3D-reflector can be excluded. A 3D-reflector consisting of more than 32 edges, those further edges cannot be excluded. Button „Exclude Edges“ CadnaA - Reference Manual 74 3 Chapter 3 - Obstacles 3.7 3D-Reflector Dialog Exclude Edges 3 List „Excluded Edges“ Click once on the edge's designation (e.g. E01) to exclude this edge from the next calculation of diffraction. Graphic Display An edge having been excluded is displayed in the graphics without a facade point symbol (octagon) attached. A further click on the designation includes the edge again into the calculation of diffraction. On the lower graphics, the actually selected edge is marked by a thick black line. Alternatively, a double-click onto an edge in the graphics excludes/includes this edge. Zooming in the Graphics After a mouse click into the graphics the sketch can be zoomed in/out. CadnaA - Reference Manual 3 75 Chapter 3 - Obstacles 3.7 3D-Reflector In conjunction with the application of the 3D-reflector, several questions may arise which are answered in the following. Additional Information The majority of calculation standards or guidelines just allow for barriers standing vertically on the reference plane, with the upper edge being straight and possibly inclined. The 3D-reflector offers a solution for special cases where one or more of the following characteristics have to be considered: Restriction to specific Standards/Guidelines • reflection from irregularly limited vertical surfaces, • reflection from surfaces which are neither horizontal, nor vertical, • diffraction at arbitrarily edges, including diffraction upwards. This solution represents a „stand-alone“ solution, since the calculation of the reflection and the diffraction at the 3D-reflector occurs without considering the (potential) interactions with other screening/diffracting objects. In order to calculate the screening effect, only those standards and guidelines are suitable which are just using the geometrical path length difference, not using an additional height (e.g. in order to correct for a parabolic ray path across the top edge). In addition, no standards or guidelines are appropriate, based on the so-called „most effective“ barrier or similar criteria. These methods are not suitable in the case of 3D-reflector since the edge determining the final screening effect can be oriented freely in space where above corrections do not apply. The equations used by standards to calculate the screening effect just refer to plane barriers. Thus, it requires to enforce a plane barrier by the software if necessary. This is done in the first calculation step (see section "Software-internal procedures" below). Restriction to plane barriers Since the 3D-reflector is freely orientable in space, reflecting rays from the 3D-reflector‘s surface (for 1st order of reflection) may point to the ground. Restriction to 1st order reflections Further, since all algorithms used for prediction of the sound propagation outdoors do not use image source to consider ground reflection (but based on source/receiver height, as well as their distance), this ground reflection could not be included into the image source method without violating the ba- CadnaA - Reference Manual 3 76 3 Chapter 3 - Obstacles 3.7 3D-Reflector sic principles of sound propagation models. Therefore, reflections higher than the 1st order cannot not be allowed. 3 Note, furthermore, that reflections - as with all other types of reflective objects - are included in the calculation only when the respective ray paths can be constructed geometrically (with angle of incidence = angle of reflection). In case a reflection path cannot be constructed, the reflection from this object can, nevertheless, be relevant acoustically, but cannot be included in the calculation because of limitations of the ray tracing approach. This illustrates that the construction of reflecting paths using ray tracing just serves as a reasonable approximation. CadnaA - Reference Manual 3 77 Chapter 3 - Obstacles 3.7 3D-Reflector As part of the calculation the following software-internal procedural steps are carried out: • • The input of a 3D-reflector occurs using a polygon having any shape and with an individual height at each polygon point. In this step it is checked whether the entered polygon creates a plane surface (see „user defined 3d polygon“ in the figure below). If this is not the case, the new z-coordinates are determined causing all polygon points to be in-plane and the sum of the squared height differences dH are a minimum (see „plane 3D polygon used for calculations“). The entered object coordinates, however, are kept for display. The image source method is applied to calculate of reflections the reflection point, if any. The reflection (specified by the absorption coefficient or the reflection loss) is taking into account only when the reflection point lays inside of the polygon (causing a separate reflected ray). CadnaA - Reference Manual Software-internal procedures 3 78 3 Chapter 3 - Obstacles 3.7 3D-Reflector • 3 In the calculation of diffraction it is assumed that three diffracted rays contribute to the receiver level: across the direct path and two lateral paths. For this purpose, the following strategy is applied: If source and receiver are located at different sides of the 3D-reflector (i.e. the line between source and receiver intersects with the 3D-reflector), the intersection point S inside the polygon is calculated (see figure below). The ray path having the smallest path length difference and thus provides the highest contribution is evaluated. This is achieved by calculating the distances of all polygon edges from the intersection point. The shortest distance determines the edge with the largest contribution. Using the length (Q-S1*-P) - (Q-P) the attenuation for this path calculated (see figure below). CadnaA - Reference Manual Chapter 3 - Obstacles 3.7 3D-Reflector • • The calculation of lateral screening is carried out as follows: The two points S2* and S3* that are used for the calculation of lateral diffraction are found by calculating the intersection of the straight line through S (laying in the reflector‘s plane) having a right angle towards S-S1* (see figure below). The contributions of these two lateral diffraction rays and of the diffracted direct path results the final screening effect. In the figure below all three diffracted ray paths are shown in blue. CadnaA - Reference Manual 3 79 3 80 3 Joints to other obstacles 3 Chapter 3 - Obstacles 3.7 3D-Reflector Joints between normative objects (e.g. between buildings and barriers) are recognized by CadnaA automatically, thus requiring no intervention by the user. With the 3D-reflector, however, interactions with other screening objects are not seen and not considered. For example, is not checked and not automatically detected whether a 3D-reflector is situated close to any other obstacle (e.g. a neighboring building). In these situations, the diffraction around the edge in question is not prevented for automatically (see also section "Screening effect" further in this chapter). However, the user may exclude one or more edges of 3D-reflector from the calculation of diffraction. Please note again that the calculation of reflections and of the screening effect of the object „3D-reflector“ is not treated in any standard or guideline. The solution provided in CadnaA may be understood as a plausible extension of ISO 9613-2, RLS-90 and Schall03 (1990) or Schall03 (2014). Even with these standards or guidelines it cannot be assured that always reasonable screening effects result in arbitrary object combinations. CadnaA - Reference Manual 3 81 Chapter 3 - Obstacles 3.7 3D-Reflector The following section describes what screening effect results using a single 3D-reflector or in combination with other screening objects. Screening effect With just a single 3D-reflector in the ray path, the strategy as described in the section "Software-internal procedures" is applied (see above). Single 3D-reflector in ray path With several 3D-reflectors in the ray path, the screening effect by each 3Dreflector is calculated individually, using the strategy as described in section "Software-internal procedures". Afterwards the final screening effect equals to the highest screening of all 3D reflectors in the path. This value is used to calculate the final barrier attenuation Abar.. Several 3D-reflectors in ray path In order to understand this approach, the following hints are useful to consider: The strategy (based on the shortest path difference of the direct path) would, being applied consistently for multiple 3D-reflectors in path, cause a more or less meandering path of the diffracted ray around all obstacles. Since every 3D-reflector may have an arbitrary shape and freely orientated, the diffracted ray would not travel always across the upper edges of obstacles, but could travel once across the top edge, then across the bottom edge or around the left or right edge. It will be appreciated that this approach would lead to an unrealistically large path difference and thus an heavily over-estimated screening effects. In the end, this effect must be controlled and suppressed by the algorithm used. When there are one or more 3D-reflectors and other „conventional“ obstacles in path (e.g. buildings, barriers, embankments etc.), first the combined screening effect Abar,conv of these obstacles using the „rubberband-method“ is determined. Subsequently, for each 3D-reflector the screening effect Abar,3D,n is determined individually (see above). The final screening effect for this ray path equals to the highest Abar, conv or Abar, 3D,n and is used to calculate the final barrier attenuation Abar. CadnaA - Reference Manual 3D-reflector and other obstacles in ray path 3 82 3 Application 3 Chapter 3 - Obstacles 3.7 3D-Reflector On the following, some situations are described, which may be modeled using either the 3D-reflector or another type of obstacle object or a combination of obstacles. Some of the situations shown, can neither be modeled using the available types of obstacles or the solution provides just an approximation. • surface providing screening upwards with a source/s below or with a lateral obstacles in addition (keyword: „gas station roof“) screening surface in free space screening surface in free space with lateral screening vertical surface CORRECT: 3D-reflector used for modeling a elevated screening surface above the ground, no other screening objects attached to its edges WRONG: modeled using several 3D-reflectors (for wall and roof) or vertical barrier (wall) and 3D-reflector (roof) The sound power of the source/s below needs to be increased to consider roof-toground multiple reflections. Explanation: The ray path is not determined by common path difference since the joint wall/roof is not „seen“. CORRECT: modeling by using a barrier with a cantilever The sound power of the source/s below needs to be increased to consider roof-toground multiple reflections. CadnaA - Reference Manual Chapter 3 - Obstacles 3.7 3D-Reflector • 3 83 cantilevered canopies at buildings („delivery/supply ramp“) 3 WRONG: modeled the canopy by a 3Dreflector attached to a building CORRECT: modeled the canopy by a cantilevered barrier attached to the building Explanation: The ray path is not determined by common path difference since the joint 3d-reflector - building is not „seen“. The screening effect in the ray path is determined by that obstacle only providing the highest screening effect. Explanation: At the cantilevered barrier the common ray path, from the vertical and the horizontal part of the barrier, is considered for all path directions. CadnaA - Reference Manual The sound power of the source/s below needs to be increased to consider roof-toground multiple reflections. 84 3 Chapter 3 - Obstacles 3.7 3D-Reflector • semi-open or partially open enclosures etc. (source inside) 3 WRONG: modeled using several 3D-reflectors (for wall and roof) or vertical barrier (wall) and 3D-reflector (roof) or barrier/s with cantilever Explanation: The ray path is not determined by common path difference since the joint wall/roof is not „seen“. Even when just using barriers with cantilever the interior level is not correct since it does not include roof-to-ground multiple reflections. CORRECT: modeled using a building and a vertical area source modeling the opening sound power of the area source does not include the possibly increased emission due to internal reflections, A simplified approach would be to use a point source instead of a vertical area source attached to the building‘s facade. CadnaA - Reference Manual Chapter 3 - Obstacles 3.7 3D-Reflector • 3 85 buildings on top of each other or with changing cross-section with height or with inclined facades towards the ground 3 WRONG: modeled by a more or less complex combination of 3D-reflectors (each being triangles) arranged in free space. Explanation: With multiple 3D-reflectors in the ray path, the screening effect is not based the common path length difference. In addition, the joints between adjacent 3Dreflectors are not „seen“. The easiest approach would be to replace the complex combination of 3D-reflectors just by a single (possibly floating) barrier, perpendicular to the ray‘s direction. CORRECT: using the object „Building“ to model the exterior shape. Note that the object „Building“ always raises from the ground (i.e. not floating buildings possible/ allowed). This approach represents an approximate solution based on the available normative obstacles. Alternatively, an arrangement of barriers or floating barriers (see chapter 3.2.1) may be used. see also: see chapter 3.1 "Building", section "Button "Geometry"" CadnaA - Reference Manual 86 3 Chapter 3 - Obstacles 3.7 3D-Reflector • comparing the screening effect caused by a 3D-reflector and a common vertical barrier 3 Since the screening effect by the 3Dreflector results from the shortest path length difference around all edges (plus lateral diffraction) the path across the top edge does not necessarily cause the shortest path length difference. With the object „Barrier“ the screening effect always results from the ray path across the barrier‘s top edge (plus lateral diffraction). A vertical 3D-reflector standing on the ground will, therefore, not cause the same resulting level for each source-receiver combination compared to a barrier with the same dimensions and location. CadnaA - Reference Manual Chapter 3 - Obstacles 3.8 Embankment 3.8 3 87 Embankment The object „Embankment“ traces back historically to the modeling of road noise (see, for example, RLS-90, /17/). At this time, terrain models were not commonly used when modeling the sound propagation outdoors. The embankment has the following properties: • In acoustical terms, the embankment represents a double barrier with parallel diffracting edges at the distance of the „Top Width“ (vertical spacing of the screen edges). • The entered polygon is the baseline of the embankment. A positive slope generates the embankment to the right of the baseline, a negative slope to the left of it. • The upper edge of the embankment above the reference plane is given by the parameter „relative Height“. • Specifying a height on the dialog Polygon: Geometry raises the baseline of the embankment by the value entered. In general, the relative height of the embankment is zero (meter). • The embankment acts as a shielding object only, not as a reflecting one. Embankment in plan view (2D view) Sectional view of the embankment For more information regarding the guideline-specific properties of the object „Embankment“, see chapter 6.2.9 "Industry Tab", chapter 6.2.10 "Road Tab", and chapter 6.2.11 "Railroad Tab". CadnaA - Reference Manual 3 88 3 Chapter 3 - Obstacles 3.8 Embankment 3 Embankment in 3D-view Furthermore, the following properties of the embankment with respect to terrain modeling are relevant: • The slope shown in the 3D view is drawn starting from the baseline and serves to identify the object as type „embankment“. • This slope shown in the graphics does not represent terrain and, therefore, does not influence the ground attenuation. In case a terrain model is present in parallel, the resulting ground attenuation is just determined by the terrain shape generated from the terrain model. The embankment is - despite looking like a terrain formation in the 3D view - not considered with other terrain-shaping objects (such as height points and terrain contours) in the triangulation. In particular, the two screening edges are not triangulated to nearby terrain contours, i.e. forming a „gap-free“ terrain. This is not an error, but due to the fact that the embankment is not a terrain-shaping object. CadnaA - Reference Manual 3 89 Chapter 3 - Obstacles 3.8 Embankment Dialog Options 3 see chapter 4.4.2 in the manual "Introduction to CadnaA" Name, Memo-Window, ID, ObjectTree This parameter defines the height of the embankment‘s upper edge. relative Height (above baseline) The slope of the embankment being positive is drawn to the right, looking from first to last point, while a negative value it will be drawn to the left. Slope 1: The perpendicular distance of the two parallel screening edges of the doublebarrier. Top Width (m) The object is an open polygon and the object height entered on the dialog Polygon: Geometry refers to the embankment‘s baseline. In general, the relative height is zero (meter). Otherwise, all options on the dialog are available (see chapter 4.2.2 "Line-like Objects"). Button „Geometry“ Further Information The command Parallel Object from the context menu of a road enables to generate an embankment parallel to this road by specifying the distance (distance road axis - baseline, see chapter 11.19 in the manual „Introduction to CadnaA“). Parallel Object When converting embankments to barriers (e.g. after a barrier optimization) the height attribute HREL of the embankment is written automatically to the attribute HA of the barrier (see chapter 11.13 "Convert to" in the manual „Introduction to CadnaA“). Conversion into barrier see also: chapter 3.8.1 Automatically Optimize Noise Barriers CadnaA - Reference Manual 90 3 Chapter 3 - Obstacles 3.8 Embankment 3 CadnaA - Reference Manual Chapter 3 - Obstacles 3.8.1 Automatically Optimize Noise Barriers 3.8.1 3 91 Automatically Optimize Noise Barriers CadnaA is able to determine automatically the required height of a noise protection wall/barrier which is needed to obey given maximum levels by means of iterative calculation. The optimization occurs for up to four evaluation parameters. 3 The wall optimization is limited to a maximum of 100 receivers. In addition, due to the algorithm applied, no multi-threading is used in the calculation, thus requiring more computation time - especially with many active receivers - than a normal calculation at receivers. Due to the object’s data structure, for such an optimization the object „Embankment“ is used a nd not the object „Barrier“. The following example shows the sequence of actions. Road with a Noise Barrier and a Receiver Point The represented road exceeds the permitted value at the receiver point. Therefore a noise barrier shall be constructed in the given position in such a way that the permitted value is not exceeded. To perform an optimizing calculation it is necessary to assign the relevant maximum value as a standard Level (in dBA) to the receiver points. It is not relevant whether the maximum value has been entered directly or whether it is determined from the type of land use. In the latter case, it might need to define suitable types of land use first (see chapter 5.2.1). CadnaA - Reference Manual Examples\03_Obstacles\OptimizeBarriers\ OptimizeBarriers_1.cna 92 3 Chapter 3 - Obstacles 3.8.1 Automatically Optimize Noise Barriers The optimization occurs for up to four evaluation parameters simultaneously. 3 Receiver: standard level assigned The object „Embankment“ must be given • • a slope of 1:0 and a top width of 0 Do not enter a value for height - this is what CadnaA is supposed to determine. dialog Embankment: all values zero In the next step we subdivide the noise barrier with the „Break into Pieces“ command from the context menu of the Embankment. In the example 10 sections of identical size have been formed. Now select an appropriate view in the menu Options|3D-View, e.g. isometric. CadnaA - Reference Manual 3 93 Chapter 3 - Obstacles 3.8.1 Automatically Optimize Noise Barriers 3 Options|3-D-View „Isometric“ In the toolbar of this dialog you can find the symbol „Optimize Barrier“. After clicking, the parameter dialog will open and we can define our strategy of optimization. The table below shows two possible settings: Settings A Settings B In the upper text box a pattern similar to the group definition can be entered by which only the walls with identical ID-codes will be integrated into the optimizing calculation. With settings A all activate embankments are considered within the optimization, while with settings B only the embankments with the string Barrier plus two additional characters. CadnaA - Reference Manual Start to optimize 94 3 3 Chapter 3 - Obstacles 3.8.1 Automatically Optimize Noise Barriers With every step of the calculation a barrier section is raised by the value given in „element height“. The shorter the sub-elements are and the smaller the element height is, the longer the calculation takes. The result of multiplying „Element Height“ by „Maximum Number of Elements“ is the upper limit for the height of the barrier. In the following combo box you can select the name „area“ or enter any other name, e.g., the product name of a noise barrier. In the first case, the value 1, in the four subsequent boxes, will remain unchanged and optimization is executed in a way that the entire surface of the noise protection wall is minimized. With the setting A the further sample calculation is executed. With settings B in the right figure takes into consideration the fact that the costs per square-meter can depend on the height of the noise barrier because costs for a foundation have to be apportioned and because, with the increasing height of the wall, greater wind pressures will have to be withstood. Optimizing is then executed in a way that will minimize the total cost. Please note that the combo box „Cost/m²“ must not be left without an entry. The cost schedule of a noise barrier can be saved/deleted with the corresponding buttons. A saved cost schedule, valid for all projects, will be at your disposal in the combo box. After the setting A has been confirmed, the optimizing calculation starts. Subdivision of the noise barrier into sections of 10m each - Calculation with the settings A CadnaA - Reference Manual 3 95 Chapter 3 - Obstacles 3.8.1 Automatically Optimize Noise Barriers An element width of 3 m leads to the following representation. 3 Subdivision of the noise barrier into sections of 3m each - Calculation with setting B CadnaA first checks if the maximum value („Standard Level (dBA)“) has been exceeded at the maximum height of all wall elements - in this case a message box will pop up. After the corresponding modification of the configuration the calculation will be restarted. Please note that with optimizing barriers all settings of the program will be considered. This is valid for projection, reflection and consideration of all activated elements. Owing to the large number of steps of calculation it is always advisable to deactivate all objects that have no effect on the result. Another alternative is to cut the relevant part out of the entire project - the optimized wall will then be imported into the project. In the following example a noise barrier will be positioned in the given location in front of a gap in a way that a maximum value, given for the receiver point behind the gap, can be maintained. Initial Situation CadnaA - Reference Manual Examples\03_Obstacles\OptimizeBarrierGap.cna 96 3 Chapter 3 - Obstacles 3.8.1 Automatically Optimize Noise Barriers In this case the wall is subdivided into 42 elements with a width of 1 m. This leads to a contour of the upper edge of the wall as shown in the illustration below. Calculation was executed „strictly according to RLS90“ with buildings considered as non-reflecting. 3 Optimizing a barrier with calculation „strictly according to RLS-90“ Now, the calculation is repeated with buildings considered as reflecting, considering reflections up to the 5th order. Lateral diffraction will also be included, in opposite to the standard procedure of RLS-90. This is appropriate in this case as this situation cannot be evaluated correctly ignoring lateral diffraction. As the result shows, a much higher wall would be necessary to meet this non-trivial situation. Optimizing a barrier with a 5th order reflection With the optimization of barriers CadnaA is able to perform an efficient positioning of noise reducing constructions. CadnaA - Reference Manual Chapter 4 - Topography 41 Chapter 4 - Topography The topography (or the terrain profile) has two major effects on the propagation of sound and on the calculation of sound propagation: 1. The topography determines the height of sources, of screening objects and of receivers, provided the height has been specified as relative height above the ground. The terrain profile may affect significantly, in particular at short source-receiver distances, the path length difference and thus the sound ray‘s length. The path length difference and the distance determine the screening (=Abar, i.e. the „barrier attenuation“ by terrain), the geometrical divergence and the air absorption. 2. Usually, by evaluating the ray path and the terrain profile, the ground attenuation is calculated from the ray‘s average height and the distance source-receiver. This procedure is used by the majority of ground attenuation models which consider the real terrain profile to calculate the ground attenuation (for example, ISO 9613-2 /8/). More sophisticated ground attenuation models do not use distinct rays, but consider the complex ground impedance and add the direct ray and the ray reflected by the ground, respecting the phase information (e.g. Harmonoise /4/) . Any sound propagation software considering the terrain profile during the calculation evaluates the (absolute) heights of all objects involved in the sound transmission and having relative object heights using the height information available from the input data. In principal, this terrain model may consist of terrain contours, height points, and lines of fault. Moreover, also objects the absolute ground height which has been specified may determine the local terrain profile. CadnaA - Reference Manual 4 2 4 Practical Hints 4 Chapter 4 - Topography In practice, often different levels of detail may be discovered with terrain models which are mostly determined by the availability of input data. Since the majority of terrain data are imported and not entered manually this data is mostly used „as is“ without being in the position to adapt the level of detail to the requirements of sound propagation calculation. Therefore, it may be useful - especially at a high level of detail - to reduce the complexity of a terrain model in order to save computation time without loosing accuracy of prediction. The following points may be relevant when assessing the suitability of an existing terrain model to be used for sound propagation calculation: Terrain Model from Terrain Contours • In case the terrain model consists of terrain contours, height steps from 1 to 5 m are useful for the purpose of sound propagation calculation. This means, for example, that adjacent terrain contours differ by 1 meter in their absolute height. An even smaller vertical stepping leads - in general to longer computation times without causing an additional screening effect. A vertical stepping being larger than 5 meters may cause relevant terrain details (such as local cuts or peaks) to be ignored in the calculation of sound propagation. Examples 3D-Special view of a terrain model with equidistant height differences between the terrain contour of 1 m CadnaA - Reference Manual 43 Chapter 4 - Topography 4 3D-Special view of a terrain model with equidistant height differences between the terrain contour of 6 m • A terrain model consisting of individual height points may have horizontal distances from 1 to 10 m between the height points. In case such terrain models are imported from data provided by the local or national ordnance survey the height points usually form an equidistant grid. Nevertheless, terrain models may also consist of irregularly distributed heights points (e.g. resulting from aerial surveys (laser dots) or from surveys of road cross section). Terrain Model from Height Points Examples Terrain model of equidistant height points CadnaA - Reference Manual 4 4 Chapter 4 - Topography 4 Terrain model from non-uniformly distributed height points Terrain Model from Terrain Contours and Height Points • With a mixed case (i.e. the terrain model consists of both, terrain contours as well as height points), it cannot be judged per se, whether the resulting terrain model is useful and not over-determined. CadnaA - Reference Manual 45 Chapter 4 - Topography • With just a few terrain forming objects - either being terrain contours and/or height points - it must be assessed in each individual case whether the terrain model is suitable and valid and whether it can be used in sound propagation calculation. Remember when having a rough and sketchy terrain model that the triangles generated in the triangulation may be very large and can, consequently, not represent properly the real terrain shape (see chapter 6.2.6). The result will be a terrain model with spatially varying precision representing the real terrain just to a minor extend. Terrain Model with only a few terrain forming objects 4 Example Terrain model with a few, unevenly distributed terrain contours (solid lines) with non-equidistant height differences (2 to 4 m). The triangulation (dashed lines) generates large triangles of terrain with constant slope. In these areas, the digital terrain model represents the terrain‘s real profile only approximately. CadnaA - Reference Manual 6 4 Terrain Models and Project Area 4 Chapter 4 - Topography • Terrain models should extend beyond the actual project area in order to cover also ray paths propagating tangentially along the actual project area (i.e. the area where the sources, the obstacles and the receivers are located). Otherwise ray paths may exist propagating across terrain parts being outside of the actual terrain model. In those cases, the terrain‘s slope and thus the resulting screening effect by the terrain as well as the ray‘s average height (ground attenuation) would be at random in this area and depending on the limit‘s corners (see chapter 9.1). Example Town model with a terrain model being too small: The rays (in blue color) extending from relevant sources (in this case the road sections on the right) cross terrain without explicit height defined by terrain forming objects (e.g. terrain contours). The resulting screening effect of the triangulated terrain contours (dashed lines) is at random, because it also depends on the location of the project‘s limits. CadnaA - Reference Manual 47 Chapter 4 - Topography In order to assess the required and reasonable level of detail, it is useful to know the software-internal procedure when evaluating digital terrain models in the process of sound propagation calculation. In the following, this processing of height information in CadnaA is described. • By default, each section of a terrain contour - whether it was entered or whether it results from triangulation - generates a screening edge with this line as the top edge (holds also for lines of fault). This replacing screen stands perpendicular to the reference plane having an absolute height of 0 meters. The entered height of a terrain contour (on dialog Geometry) is always interpreted as an absolute height. • When the terrain is solely modeled by using height points, these will not provide any screening, but only the terrain contour lines resulting from the triangulation. In this case, ensure that the option „Explicit Edges Only“ on the „DTM“ tab (see chapter 6.2.6) is not activated. • Lines of fault are superfluous in conjunction with the triangulation, since they can be replaced by two parallel terrain contours. Otherwise, the heights left/right has to be specified and are not automatically derived from the actual terrain model. Prior to the calculation of propagation CadnaA calculates the absolute heights of all vertices of all objects: • For objects with specified relative heights, the absolute level of the terrain at the base point and the height above the reference plane are determined using the local terrain height as resulting from the triangulation of the terrain forming objects. • For objects with absolute heights, this height represents the final height. • For objects the height of which has been specified using the height attribute option „Height above Roof“ the same procedure as with relative heights applies, while, in addition, the height of the surrounding object is considered when determining the absolute heights. CadnaA - Reference Manual Software-internal Procedure 4 8 4 4 Chapter 4 - Topography • For objects that have been entered using the height attribute „absolute Height/Ground at every Point“ just the object‘s height is taken into account by default. In order to respect the ground it requires that the option „Objects with Ground at every Point influence DTM"“ is activated (see chapter 6.2.6). • The object height is evaluated for line-like objects (i.e. open polygon lines, e.g. line sources, roads, railways, barriers etc.) for each vertex point of the polygon, for area-like objects (i.e. closed polygons, e.g. for area sources, parking lots etc.) for each vertex point of the polygon, for buildings (being a closed polygon) just for the first polygon point. This refers to the first polygon point as listed on the dialog Geometry of the object „Building“ (first point). Within the calculation of sound propagation a sound ray reaching from the source to the receiver intersects with all intervening terrain contours and lines of fault (and also with all other screening objects). In this course, the path length difference and, consequently, the screening effect caused by terrain edges and other objects is determined. In addition, from the height of the sound ray above the terrain at all intersecting points and from the path lengths between these points the average ray‘s height is calculated by iteration, finally resulting in the ground attenuation. The terrain height at the source and the receiver are also considered. CadnaA - Reference Manual Chapter 4 - Topography 4.1 Terrain generating Objects 4.1 49 Terrain generating Objects In general, the specification and the generation of a terrain model makes use of the following terrain forming objects: • terrain contour or „contour line“ (see chapter 4.1.1) • height point (see chapter 4.1.2) • line of fault (see chapter 4.1.3) The object „Line of Fault“ is superfluous when generating terrain by triangulation and should, therefore, no longer be used in this case. Furthermore, all objects having specified the local terrain height in the object‘s geometry may determine the terrain height. This holds for the following object types and their respective geometry options: • point objects: The option „Ground Height: input of value (m)“ is selected. In this case, the entered value is relevant (see chapter 4.2.1). • line and area objects: The option „absolute Height/Ground at every Point“ is selected. In this case, the values specified in column „Ground“ of the geometry table are relevant (see chapter 4.2.2 and 4.2.3). However, these objects are relevant when generating the terrain as long as the option „Objects with Ground at every Point influence DTM“ on the „DTM“ tab is activated (see chapter 6.2.6). In this case, the terrain heights of these objects determine the terrain‘s level at this location. Otherwise these objects, even though an individual terrain height has been specified, will be ignored when generating the terrain model. In this case, the object height results from the sum of the local terrain height and the object‘s relative height. In case an absolute height has been entered for the object, however, the entered local terrain height is ignored. CadnaA - Reference Manual 4 10 4 Example Chapter 4 - Topography 4.1 Terrain generating Objects The height of a point and a line source are specified using the options „Ground Height: input of value (m)“ and „absolute Height/Ground at every Point“. Option „Objects with Ground at every Point influence DTM“ activated Option „Objects with Ground at every Point influence DTM“ deactivated The entered ground height in the object‘s geometry is considered when triangulating the terrain. The entered ground height in the object‘s geometry is not considered when triangulating the terrain. 4 blue: point and line source blue: point and line source red: triangulated terrain edges (limits: 1000 x 1000 m) red: There is just a single terrain edge at a height of 0 m between the corners of the limits (from (x,y)=(0,0) to (1000,1000) m). CadnaA - Reference Manual Chapter 4 - Topography 4.1.1 Contour Line 4.1.1 4 11 Contour Line The object „Contour Line“ is used - besides the object „Height Point“ - to model the topography resp. the terrain‘s profile. By the polygon of a contour line (terrain contour) a defined height above the reference plane is defined. The height profile of the polygon is specified as with line-like objects (see chapter 4.2.2). Prior to the actual calculation of propagation, the final terrain profile is interpolated using the heights assigned to the terrain forming objects, applying the procedure as specified on dialog Calculation|Configuration, „DTM“ tab (see chapter 6.2.6) By default, the triangulation method is applied. In the calculation of sound propagation, the terrain profile may cause screening and affect the ground attenuation. The absolute level of objects whose height has been entered as relative heights is determined from the object‘s height and the terrain model. When calculating sound propagation the contour lines are considered as being the upper edges of barriers. Terrain contours generated by interpolation (e.g. by triangulation) between the entered contour lines cause, by default, also screening (provided the option „Explicit Edges Only"“ on tab „DTM“ is deactivated, see chapter 6.2.6). When calculating the screening by terrain no lateral diffraction is accounted for. On the table Contour Line (on menu Tables|Obstacles) just the first and the last point are listed (with option „Interpolate Height from First/Last Point“). The height entered is always interpreted as absolute height. Dialog Contour Line CadnaA - Reference Manual 4 12 4 Chapter 4 - Topography 4.1.1 Contour Line Dialog Options 4 Name, ID code, MemoWindow, ObjectTree see chapter 4.4.2 in the manual „Introduction to CadnaA“ Option "Use Points as Height Points" This option offers to save a terrain model made from height points as contour lines where the vertex points of each contour receive the height of each height points (with geometry option „Height at every Point“). In order to convert height points into a so-called height point cluster, see chapter 4.1.2, section "Use Contour line as Cluster of Height Points". By activating this option, the heights points making up the contour line are displayed in the graphics using the height point‘s symbol, but using the color setting for contour lines. Button "Geometry" see chapter 4.2.2 of this Reference Manual CadnaA - Reference Manual Chapter 4 - Topography 4.1.1 Contour Line When having imported terrain contours from external file formats it may be necessary to toggle the height attribute HA_ATT (see chapter 1.1 in the manual „Attributes, Variables, and Keywords“) from „Interpolate Height from First/Last Point“ to „absolute Height at every Point“. Since the height information of terrain contours always represents absolute heights, changing the height attribute may not be possible by using the default attribute abbreviations (see chapter as mentioned above). In this case, proceed as follows: • Select the command Modify Objects from the context menu of the CadnaA main window. • Select the action „Modify Attribute“ for the object type „Contour Line“. • From the subsequent dialog, select a height attribute HA_ATT. • Activate the option „Replace Strings“ and delete the entry under „Replace with“. • Click OK and confirm the action with „All“. Afterwards, the height attribute of the contour lines is set to „absolute Height at every Point“. Changing the height attribute HA_ATT of terrain contours CadnaA - Reference Manual 4 13 Toggling the height attribute of terrain contours 4 14 4 Chapter 4 - Topography 4.1.1 Contour Line 4 CadnaA - Reference Manual Chapter 4 - Topography 4.1.2 Height Point 4.1.2 4 15 Height Point The object „Height Point“ is used - besides the object „Contour Line Point“ - to model the topography resp. the terrain‘s profile. Note that when modeling terrain by using height points - in contrast to contour lines and lines of fault - a screening effect will just result from the triangulated terrain edges generated between the height points. This requires that the option „Triangulation“ in the dialog Calculation| Configuration, tab "DTM" (see chapter 6.2.6), is selected and the option „Explicit Edges Only“ is deactivated. Terrain model just made of height points, option „Explicit Edges Only“ deactivated Terrain model just made of height points, option „Explicit Edges Only“ activated Result: A shielding effect by triangulated terrain edges occurs. Result: No screening effect occurs. CadnaA - Reference Manual 4 16 4 Chapter 4 - Topography 4.1.2 Height Point By using height points a defined height above the reference plane is assigned. The height is specified according to the geometry of point-like objects. The absolute height of objects having been entered using relative heights is calculated using the ground height resulting from the terrain model. 4 Dialog Height Point Dialog Options Name, ID code, Memo-Window, ObjectTree see chapter 4.4.2 in the manual „Introduction to CadnaA“ x (m), y (m) coordinates of the height point in the selected coordinate system Height z (m) absolute height of the height point Button „--> RefPoint“ see chapter 4.2.4, section "Filling the List of Reference Points" CadnaA - Reference Manual 4 17 Chapter 4 - Topography 4.1.2 Height Point Many height points require a large amount of memory and, thus, increase the size of the project file (also due to the fact that for each height point the name and the ID have to be stored separately). To save memory you may convert the height points into contour lines using the command Modify Object (action „Convert to“, object type „Height Points“). This action generates a cluster of height points where each cluster may consist of up to 1000 height points joined to a contour line. The contour lines can be converted back again into individual height points. Use Contour line as Cluster of Height Points • Open the file HP.cna containing about 4,000 height points. Examples\04_Topog- • Open the dialog Modify Objects, selected the action „Convert to“ for object type „Height Point“ and confirm by OK. • On the dialog Convert Objects select the target object type „Contour Line“. • Click OK and confirm by „All“. • Open from the Tables|Obstacles menu the table Contour Lines. 4 raphy\HP.cna The height points have been converted into five contour lines. The file size has been reduced by this operation by nearly a half. • Move the table a little aside and mark some table rows one after the other. The respective height point cluster will be highlighted. An ASCII file with xyz coordinates of height points can either be imported using the command File|Import, import format „ASCII-Objects“ (see chapter 7.2.18 "ASCII-Objects"), or via the ODBC-interface (see chapter 7.3 "Import via ODBC Interface"). CadnaA - Reference Manual Import ASCII-File as Height Points 18 4 Chapter 4 - Topography 4.1.2 Height Point 4 CadnaA - Reference Manual 4 19 Chapter 4 - Topography 4.1.3 Line of Fault 4.1.3 Line of Fault The object „Line of Fault“ is superfluous in conjunction with the terrain generation by triangulation (see chapter 6.2.6) and should, therefore, no longer be used in this case. When using the triangulation, the same effect on the terrain model is caused by two parallel contour lines, the one having the height of the lower, the other the height of the upper terrain level. 4 The line-of-fault has been used in conjunction with the historical methods for generating a digital terrain model (options „Search Contour Lines (Average)“ and „Search Contour Lines (Local Inclined Plane)“ on dialog Calculation|Configuration, „DTM“ tab (see chapter 6.2.6) to cause a jump in terrain height on both sides by the nearest contour lines or other height points (e.g. base points of buildings). Dialog Line of Fault Dialog Options see chapter 4.4.2 in the manual „Introduction to CadnaA“ CadnaA - Reference Manual Name, ID code, MemoWindow, ObjectTree 20 4 Chapter 4 - Topography 4.1.3 Line of Fault Button "Geometry" 4 Dialog Geometry of a Line-of-Fault • option „absolute Height at every Point“: After double-clicking into a row of the polygon point table, the absolute height to the left and to the right of the line-of-fault can be entered. CadnaA - Reference Manual 4 21 Chapter 4 - Topography 4.2 Object’s Geometry 4.2 Object’s Geometry CadnaA offers to specify the local ground height within the geometry of ob- jects (option „Ground Height“: Input of Value (m)“ or option „absolute Height/Ground at every Point“). Thus, depending on the setting of the option „Objects with Ground at every Point influence DTM“ on the „DTM“ tab, these objects will influence the resulting terrain model (see chapter 6.2.6). 4.2.1 4 Point-like Objects The geometry of point objects (such as point source, receiver etc.) is specified by the coordinates x, y, and the (absolute) height z. These values are listed on the respective columns of the corresponding object table (see chapter 11.1). For the object „Cylinder“ there are, besides the x and y coordinates, the cylinder‘s center and its radius. For height points the entered height (z) is always interpreted as absolute height. Dialog Point-Geometry with point objects On the dialog Point Geometry the height h (m) can be entered relative, absolute or relative to a building‘s roof. From the height h and the ground height the absolute height z results. CadnaA - Reference Manual Dialog Options Point Geometry 22 4 Options for Height Chapter 4 - Topography 4.2.1 Point-like Objects • Option „relative“: height (m) at the coordinate point (x, y) above ground level. The (absolute) level of the ground results: from terrain forming objects (contour lines, height points, lines of fault) from the standard height as specified on the „DTM“ tab (menu Calculation|Configuration, see chapter 6.2.6) and from the method used for generation of the terrain between the height defining objects (by triangulation per default). 4 Ground Height (m) & list box • Option „absolute“: height above a reference plane, usually above mean sea level (MSL). The reference height MSL might not the same to different, even neighboring countries because different definitions and references are in use. • Option „Roof“: In order to facilitate the height specification of sources on top of roofs of buildings a relative height above roof level can be entered using this option. When the source is within a building‘s outline the final height results from the sum (building height + height above roof). The input box „Ground Height“ is just available with the option „Input of Value (m)“ selected. • Calculate from DTM (default): With this option, the ground height is calculated by evaluating the present terrain model. • Use next building: With this option, the ground height of the nearest building facade within radius of 1.5 m is used. With no building facade be located within this radius the height at this location is also calculated by evaluating the present terrain model. • Input of Value (m): The ground height at this location can be specified by entering a value. CadnaA - Reference Manual Chapter 4 - Topography 4.2.1 Point-like Objects Besides the coordinates X and Y (m) the diameter (m) of the building evaluation symbol can be specified. 4 23 Geometry Options for Object „Building Evaluation“ The diameter of all building evaluation symbols in a project can be changed via the respective table (see Tables menu, Other Objects| Building Evaluation). 4 Dialog Geometry of the Building Evaluation Symbol This option enables to place a building evaluation symbol outside of the building‘s outline. When this option is activated the building evaluation symbol can be placed outside of the building without losing the link to this building. The original coordinates are saved as well. Procedure: • First place the building evaluation symbol inside of a building‘s outline. • Open the dialog Geometry and activate the option „Use different Calculation Point“. • Close all dialogs with OK and move the building evaluation symbol outside of the building‘s outline. The calculation point is indicated by a auxiliary polygon. CadnaA - Reference Manual Option „Use different Calculation Point“ 24 4 Chapter 4 - Topography 4.2.1 Point-like Objects 4 CadnaA - Reference Manual 4 25 Chapter 4 - Topography 4.2.2 Line-like Objects 4.2.2 Line-like Objects Line-like objects (e.g. line source, road, railway) are defined by a sequence of polygon segments or, respectively, by a sequence of points making up the polygon. The first and the last point of the polygon may have the same or a different height (being relative, absolute or relative heights referring to a building roof). In this case, the height of intermediate polygon points is determined by linear interpolation (option „Interpolate Height from First/Last Point“). Alternatively, for each point of the polygon may a different absolute height may be defined. 4 For contour lines the entered height (z) is always interpreted as an absolute height. Dialog Geometry of a Line Source List of polygon points: Shows the coordinates x, y, z and the ground height at the respective point. A double-click into a table row opens the dialog Polygon Point. Using the command from the context menu of the table offers for example - to delete or insert polygon points. CadnaA - Reference Manual Dialog Options Polygon: Geometry 26 4 List Box Height Chapter 4 - Topography 4.2.2 Line-like Objects option „Interpolate Height from First/Last Point“: • relative: height in meters (m) above terrain level at the coordinate (x, y). The (absolute) height of the ground results from: 1. the height of objects forming terrain (contour lines, height points, lines of fault), 2. from the standard height specified on "DTM" tab (menu Calculation|Configuration, see chapter 6.2.6) and 3. by the method applied to from terrain between the objects defining terrain height (e.g. by triangulation). 4 • absolute: Height above a reference plane, as a rule above mean sea level (MSL). The MSL height does necessarily correspond for different, even neighboring countries since different definitions and references are used. • Roof: This option facilitates the input of a height for sources on top of a building's roof. The relative height above the roof plane is entered. For a source within the building's border the source height results from the sum (building height + height above roof). option „absolute Height at every Point“: When this option is selected the absolute height Z can in addition be edited in the list of polygon points or via the dialog Polygon Point. option „absolute Height/Ground at every Point“: When this option is selected the ground height, besides the absolute height Z, can be edited in the list of polygon points or via the dialog Polygon Point. 2D-Length length of the polygon projected into the xy plane Station In order to generate station marks alongside of line-like objects an initial station value (in meters) can be specified (see chapter 9.11.4). The option "ascending/descending" defines as to whether the stationing starts increasing or decreasing from the present location. CadnaA - Reference Manual 4 27 Chapter 4 - Topography 4.2.2 Line-like Objects Initially, when entering the objects „vertical area source“ (see chapter 2.1) and „barrier“ (see chapter 3.2) in the graphics, these are represented by a 2D polygon having no height. The height (or the z-coordinate) of the polygon points for these objects (as entered via the Polygon: Geometry dialog) refers to the top edge of the object. The other dialog options comply with those for line-like objects in general. Additional information for objects „vertical area source“ and „barrier“ With floating barriers, the z extend (see chapter 3.2.1) describes the vertical height difference of the lower edge to the top edge as entered on the dialog Polygon: Geometry. vertical area source & barrier: z-extension The z-extend counts positive downwards! Consequently, the bottom and top edge are always parallel and cannot be distinguished in the 2D-plan. z-extend of a floating barrier: In this example, the barrier extends at all polygon points 3 m downwards from the top edge. When entering the object „Vertical Grid“ (see chapter 5.3.6) a height of the top edge of 20 meters is set by default. The object can consist of two points only (see dialog Polygon: Geometry). Further polygon points will be ignored. CadnaA - Reference Manual Additional information for object „Vertical Grid“ 4 28 4 Height Extend of the vertical Grid Chapter 4 - Topography 4.2.2 Line-like Objects The vertical grid extends from the height of the top edge (as specified on dialog Polygon: Geometry) down to the ground. Grid points below the terrain, however, are not displayed in the grid. Depending on the grid spacing, this causes more or less white areas on the vertical grid. Flat terrain: The vertical grid extends to the ground. 4 The dots indicate the grid points (grid spacing (1 by 1) m. Non-flat terrain: The vertical grid (spacing (1 by 1) m also extends down to the ground, but grid areas where the grid point is below the terrain profile are not displayed (white color). same as above, but now with a coarser grid spacing of (5 by 5) m. Again, the grid areas where the grid point is below the terrain profile are not displayed (white color) Additional Dialog Options for Road & Rail Besides the default geometry options of line-like objects, there are additional dialog options available for the objects „Road“ (see chapter 2.4.1) and „Railway“ (see chapter 2.6.1). CadnaA - Reference Manual 4 29 Chapter 4 - Topography 4.2.3 Area-like Objects 4.2.3 Area-like Objects The geometry of area-like objects (e.g. area source, parking lot, building, ground absorption) is defined by a list of polygon points with coordinates x, y and the height z. Area-like objects represent with respect to their geometry a closed polygon. In the same way, spatial objects (i.e. objects having a height, e.g. buildings) are defined by a closed polygon representing the building‘s outline in 2D projection and a height in addition. 4 Dialog Geometry of an area source List of polygon points: shows the coordinates x, y, z and the ground height at the respective point. A double-click into a table row opens the dialog Polygon Point. Using the command from the context menu of the table offers for example - to delete or insert polygon points. Dialog Options Polygon: Geometry The options are consistent with those of line-like objects (see chapter 4.2.2). In addition, the 2D surface is displayed: List Box Height area (in m²) of the polygon projected into the xy plane 2D-Area For the source „Parking Lot“ a height of 0.5 m is used automatically which is added to the entered height upon calculation. Besides the geometry options for area-like objects as described above the following further points are noteworthy with buildings: CadnaA - Reference Manual Additional Information for object „Building“ 30 4 Chapter 4 - Topography 4.2.3 Area-like Objects • With reference to the underlying calculation procedures buildings are, in fact, modeled from a sequence of barriers, forming a closed polygon in the xy plane and making up an „open“ box, having no roof which is acting as a reflecting surface. Therefore, the directivity index K0 or D of point, line or area sources that are located within a building‘s outline is considered based on their respective the height above the ground (and not above the roof, since there is no actual roof accounted for). • When a building has assigned different heights at its polygon points, the height of building will be determined based on the height of the first polygon point of the building (see chapter 11.7 "Modify Order of Points" in the manual „Introduction to CadnaA“). • When the option „Roof“ is activated, an area source that is located inside a buildings outline will receive a uniform height at all polygon points based on the height at the first building point. If necessary, select the option „absolute height at every Point“. • A building may also be defined with a relative height on top of a further building. To this end, activate the option „Roof“ for the inner building. In this case, the input sequence is not relevant. The underlying calculation standards just calculate the screening effect correctly with smaller buildings on top of larger buildings (like a pyramid), but not vice versa. 4 CadnaA - Reference Manual Chapter 4 - Topography 4.2.4 Additional Input Features 4.2.4 Additional Input Features In order to generate a proper sequence of a (open or closed) polygon curve (e.g. a terrain contour) additional polygon points may be entered, the heights of which are unknown. CadnaA can determine these unknown heights by linear interpolation. Proceed as follows: • Enter the polygon (e.g. a terrain contour or „contour line“) with the required number of polygon points in order to generate a proper curve. • Select on the dialog Polygon: Geometry the option „absolute Height at every Point“. • Enter the known absolute heights in column „z (m)“ at the known xy locations. • 4 31 Move both dialogs, the dialog Polygon: Geometry and the object dialog a little aside in order to see the polygon object in the main window. The currently selected polygon point is highlighted. Select in the table of points, those points one-by-one having an unknown absolute height and press the space bar to delete the default value 0 m. Dialog Geometry (here of a terrain contour): absolute height z at a polygon point has been deleted using the space bar CadnaA - Reference Manual Interpolate unknown heights of polygon points 4 32 4 Chapter 4 - Topography 4.2.4 Additional Input Features 4 Do not use the DEL key, since then the polygon point is deleted from the table. • When closing the dialog CadnaA will recalculate the value by linear interpolation. • Reopen the dialog Geometry to display the interpolated value/s. Dialog Geometry: The absolute height z was interpolated between two polygon points. Alternatively, only the polygon points with known heights can first be entered and then using the editing of polygons (see chapter 4.3.1 in the manual „Introduction to CadnaA“) additional points will be entered graphically. Then delete the column "z (m)" of the polygon point list with the space bar the initial value 0 m. CadnaA - Reference Manual 4 33 Chapter 4 - Topography 4.2.4 Additional Input Features Coordinates can be copied from the geometry of point objects as well as of polygon objects (lines and areas) to a list of reference points for later use. Consequently, there is no need to write down coordinates manually in order to enter them later. Filling the List of Reference Points Examples for using a list of reference points include the transfer of coordinates to other objects with transformations (option „Match Points“, see chapter 7.1.4) or the acquisition of coordinates when calibrating a bitmap (see chapter 10.1.1 in this manual and chapter 9.1 in the manual „Introduction to CadnaA“). In order to make use of a list of reference point with point objects proceed as follows: • Click on button „Geometry“ in the dialog of point objects to open the dialog Point-Geometry. • Click on the button „--> RefPoint“ to copy the coordinates of the point to the reference point list. • From the subsequent dialog Reference Points, select one of the four available reference points where the data will be copied to. Dialog Reference Points: reference point 2 is selected • Close the dialog Reference Points by OK. • By clicking again on button „--> RefPoint“ you can check whether the coordinates have been copied. CadnaA - Reference Manual 4 Transferring reference points for point objects 34 4 Chapter 4 - Topography 4.2.4 Additional Input Features 4 Dialog Reference Points: Point coordinates have been copied to the reference point 2 Transferring reference points for polygon objects In order to use the list of reference point list with polygon objects (lines or areas) proceed as follows: • On the object‘s dialog click the „Geometry“ button. • Double click in the table of polygon points into the row whose coordinates are to be copied as a reference point. Dialog Polygon: Geometry: After a double click in a table row the dialog Polygon Point opens. • Click the button „--> RefPoint“ to copy the coordinates of this point to the list of reference points. For additional features see section „List of reference points for point objects“ (see above). CadnaA - Reference Manual Chapter 4 - Topography 4.2.4 Additional Input Features When entering line-like and area-like objects in the graphics (not for cylinder) right angles between individual polygon sections may be enforced. 4 35 Generating Orthogonal Polygons Proceed as follows: • Select - for example - the object „Building“ from the toolbox. • Enter the first polygon point by clicking the mouse button. • Now, press the Shift key. Now, the mouse cursor is trapped in fixed steps of 90 degrees with respect to the preceding polygon section. • Click while holding down the Shift key at the position of the next polygon point. • Proceed analogously till the last polygon point has been entered. • Click with the right mouse button to close the building‘s polygon. By the last step, the first and the last point of the building are joined automatically and, thus, closing the building‘s polygon. When drawing rectangles, it is useful to start with the longer side. After having entered the third point for the shorter side, position the mouse pointer on the starting point. Please click on the starting point, to enter the third longer side automatically with it‘s correct length. Close the rectangle by a final click using the right mouse button. This procedure is recommended especially when entering buildings having a rectangular outline. CadnaA - Reference Manual 4 36 4 Chapter 4 - Topography 4.2.4 Additional Input Features 4 CadnaA - Reference Manual 4 37 Chapter 4 - Topography 4.3 Topography-specific Functions 4.3 Topography-specific Functions In this chapter, specific features (with examples) are described applicable when generating and editing digital terrain models in CadnaA. Preliminary Note In each of the following chapters the range of application and the effects of each feature are described. The presentation focuses on the software-related functions and procedures, also addressing possible user criteria when applying a feature or function. Please consider that just the mere existence of a feature or function does not mean, however, that it may be appropriate to be applied in a particular case. 4 The decision, which feature or function may apply in a particular case cannot be taken by the software itself, but remains in the responsibility of the user. The subsequent chapters cover the following program functions: • see chapter 4.3.1 "Fit Objects to DTM" • see chapter 4.3.2 "Fit DTM to Object" • see chapter 4.3.3 "Generate Terrain Contours from Height Points" • see chapter 4.3.4 "Generate a Grid of Height Points from Terrain Contours" • see chapter 4.3.5 "Generate Cluster of Heights Points from Bitmap" CadnaA - Reference Manual Topography-specific Functions 38 4 Further Features for processing Terrain Data Chapter 4 - Topography 4.3 Topography-specific Functions In addition, further software features are available which can be used when importing terrain data or in order to modify existing an terrain model. In each particular case the user decides whether a specific software feature is useful and appropriate. • 4 see chapter 11.9 "Simplify Geometry" in the manual „Introduction to CadnaA“ • see chapter 15.6 "Close Polygons" (requires option X or XL) • see chapter 15.7 "Delete Height Points" (requires option X or XL) CadnaA - Reference Manual 4 39 Chapter 4 - Topography 4.3.1 Fit Objects to DTM 4.3.1 Fit Objects to DTM The basic functions of this command are described in chapter 11.24 of the manual „Introduction to CadnaA“. The data on object heights (e.g. roads, buildings) and terrain height (i.e. height points, contour lines) often originate from different sources. In practice it occurs quite often that the given object heights (e.g. the road‘s height) does not correspond with the terrain heights. In these situations, CadnaA can fit the object height (e.g of a road or roads or other line- or area-like objects) to the terrain height by means of the command Fit Object to DTM. With this, new vertex points will be generated of the object‘s geometry, the height (z coordinate) of which will be adjusted to the local ground level. When using this command, it is assumed that the terrain model and, thus, the local height (z coordinate, i.e. the absolute height) is correct and relevant. This implies that the actual object heights are less correct and less relevant than the local terrain height. The decision whether the object heights or the terrain model is/are relevant or not, cannot be decided by the software, it is up to the user. CadnaA - Reference Manual Application 4 40 4 4 Chapter 4 - Topography 4.3.1 Fit Objects to DTM Consequences With regard to the effects caused by this command we will distinguish linelike and area-like objects in the following. Line-like Objects Examples of this type of object are line sources, roads or railways. For these objects, the entered polygon line represents the central axis of the object (especially with roads and railways). This means that even with a varying road width, the geometry (and hence the height) is known for the center line only. Thus, fitting to the terrain can, therefore, just occur for this center line, since the heights at the road‘s curbs (or on the edge of the railway track) are unknown. This holds - regarding roads - especially when a lateral slope has been entered for the road (see chapter 2.4.1). Even in this case, fitting to the terrain just occurs for the road‘s center line. The consequence is - regardless whether a lateral slope has been entered or not - after using the command Fit Object to DTM the both road curbs may either be covered by terrain or are floating above the ground. When no lateral slope has been entered the road surface is assumed to be flat. Furthermore, this may have the additional consequence that two emission lines of the road may also be covered by terrain or may float above the ground. In case a lateral slope has been entered it will be kept when using the command Fit Object to DTM. In both cases - with or without a lateral slope - no adaptation of the road curbs to the local terrain height occur. CadnaA - Reference Manual 4 41 Chapter 4 - Topography 4.3.1 Fit Objects to DTM Example 4 Road with two contour lines 3D-Special view The height is known at the polygon points of the road. Here the two points are located in flat terrain (the area between contour line at 0 m and the corners of the limits). The road is covered by the terrain because there is no height defining polygon points of the road within the hill area. When executing the command Fit Object to DTM additional polygon points are inserted to the object‘s geometry at all intersections with explicit or triangulated terrain contours. Their local ground height results from the terrain model. 3D-Special view CadnaA - Reference Manual The road is no longer covered the terrain. The fitting of the object‘s geometry is based on the center line of he road. 42 4 Chapter 4 - Topography 4.3.1 Fit Objects to DTM Nevertheless, the road may still be overlapped by terrain or be hovering above the ground at the road‘s curbs. 4 After applying the command Fit Object to DTM the road‘s curbs may still be covered by terrain or float above the terrain. With a road having a lateral slope (in this case 20%) the fitting to the DTM just occurs for the road‘s center line. CadnaA - Reference Manual 4 43 Chapter 4 - Topography 4.3.1 Fit Objects to DTM Examples of this type of objects are area sources and parking lots. Area-like Objects With area-like objects, explicit polygon points just exist for the perimeter line of the source. Inside of the area object, however, there are no polygon points the height of which could be fitted to an existing terrain model. Consequently, with an area-like object just a defective fitting to a complex terrain may result when using the command Fit Object to DTM. 4 Example An area source in a complex terrain before applying the command Fit Object to DTM Situation after applying the command Fit Object to DTM: The polygon points of the area source‘s outline have been fit to the local terrain height. However, the areas inside the source‘s outline are still below terrain. CadnaA - Reference Manual 44 4 Chapter 4 - Topography 4.3.1 Fit Objects to DTM In order to properly fit area sources to the terrain do not use the command Fit Object to DTM, but enable the option „Area sources with constant relative height follow terrain“ from the „DTM“ tab, on the Calculation| Configuration menu (see chapter 6.2.6). 4 Fitting an area source to the terrain with option „Area sources with constant relative height follow terrain“ enabled CadnaA - Reference Manual 4 45 Chapter 4 - Topography 4.3.2 Fit DTM to Object 4.3.2 Fit DTM to Object The basic functions of this command are described in chapter 11.23 of the manual „Introduction to CadnaA“. By the command Fit DTM to Object (in the context menu of objects or as an action on the Modify Objects dialog) the entire terrain model will get modified by cutting existing and inserting new terrain contour lines. When using this command, it is assumed that the current height (height z, i.e. the absolute height) of the object/objects, is correct and relevant to which the terrain model is going to get fit. This implies that the actual terrain model is assumed to be less correct and less relevant than the object height/s. The decision whether the object heights or the terrain model is/are relevant or not, cannot be decided by the software, it is up to the user. CadnaA - Reference Manual Application 4 46 4 Example Chapter 4 - Topography 4.3.2 Fit DTM to Object In this example, the command Fit DTM to Object causes to „clear up“ the road‘s surfaces from overlapping ground. Just from the existing data, however, it is not possible to assess whether the resulting geometry corresponds to reality in this area or not. 4 Terrain model prior to execution of the command Fit DTM to Object (roads having relative heights) 3D-Special view of a road canyon prior to execution of the command (roads partially covered by terrain) Terrain model with additional, road-parallel contour lines after execution of the command Fit DTM to Object 3D-Special view of a road canyon with terrain cuts after execution of the command Fit DTM to Object CadnaA - Reference Manual 4 47 Chapter 4 - Topography 4.3.2 Fit DTM to Object Using this command may cause severe changes to the original terrain model without being able to decide in advance, whether the resulting terrain model is more „real“ than the previous one. Accepting that a measure for the accuracy would be the „real terrain profile“, it would require in any case that a terrain model with a finer resolution would be available for each project in order to examine the deviations. This is, in practice, not possible for time and cost reasons. Consequences 4 It is, therefore, strongly recommended to not use this command routinely, but only in situations where a preliminary study has shown that the resulting heights difference before and after applying the command are deemed acceptable. In the following, a procedure is described to display the height differences on the grid before and after executing the command Fit DTM to Object. The situation as shown in the former example will be used assuming that the two situations are available in separate files: 1. A file with contour lines prior to execution of the command. 2. A file with contour lines after execution of the command. Proceed as follows: • First, open the file containing the contour lines before executing the command Fit DTM to Object. • Now, sort the values in column „Height, top (m)" of the table height line in ascending numerical order to determine the range of values of the altitude. CadnaA - Reference Manual Procedure 48 4 Chapter 4 - Topography 4.3.2 Fit DTM to Object 4 Sorting the first heights of the contour lines in ascending order • Check by scrolling in the table for the minimum and maximum height. • Open the dialog Grid Appearance from the Grid menu and enable the „Level Range“ option. • Enter a value below the minimum and above the maximum height as established by the scrolling from above (e.g. „70“ and „210“ for 70 m and 210 m). • Enter a class width of 5 m (meters and not dB in this case). Thus, the interpolation will be run using these specifications. Make sure prior to the calculation that no grid interpolation is set on the „General“ tab (menu Configuration|Calculation). • Enter on the Grid|Specification menu a receiver spacing of 5 m by 5 m. • Now, execute the grid calculation by selecting the command Calc Grid from the Grid menu. CadnaA - Reference Manual Chapter 4 - Topography 4.3.2 Fit DTM to Object • Toggle via the list box on the toolbar to the ground grid. • If necessary, adjust the grid appearance (see chapter 5.3.2). • Save the grid via menu File|Save As (e.g. using the filename grid prior DGMtoObj.cnr). • Save the CadnaA file using a new name. Afterwards we proceed in the same way with the file the contour lines after execution of the command Fit DTM to Object. • Save the grid via the menu File|Save As (e.g. using the filename grid after DGMtoObj.cnr). • Save this CadnaA file under a new name. Now, the difference grid is generated from the grid files. • Open the file containing the contour lines after execution of the command Fit DTM to Object, the dialog Grid Arithmetic from the Grid menu. • Download both grid files and execute operation illustrated below with the ground grids r1g and r2g from. Generating the difference grid r1g-r2g CadnaA - Reference Manual 4 49 4 50 4 Chapter 4 - Topography 4.3.2 Fit DTM to Object • If required, adjust the grid appearance by selecting a suitable color palette for evaluation parameter LP1 (see chapter 5.3.2). The following diagram „pal_0_5_step_05". makes use the provided color palette 4 Grid with height differences (grid spacing 5 m by 5 m) For the major part of the project area, the absolute height differences between the two terrain models are less than one meter (light green and dark green areas). In the street canyon, in the middle of the project area, however, the absolute height differences are locally more than 5 meters. This is due to the fact that the height profile of the road prior to execution of the command was already below terrain. As a result, the biggest local changes in height occur when fitting the terrain to the road‘s geometry. When using different grid spacings in the interpolation, different results may occur different. CadnaA - Reference Manual 4 51 Chapter 4 - Topography 4.3.3 Generate Terrain Contours from Height Points 4.3.3 Generate Terrain Contours from Height Points This software feature enables to generate a new terrain model based on sparsely distributed height points by using the interpolation provided by the grid calculation in CadnaA. Please note the following limitations when using this feature: • The subsequent generation of contour lines by grid interpolation generally reduces the accuracy of the local height information compared with the initial terrain model from height points. • The application of this feature is, therefore, useful only in cases where there are just few, spatially sparsely distributed height points across the project area available. In the triangulation, few height information results in relatively large, flat triangles of constant slope. This means that the height in these areas is approximative only. • For a given sufficiently dense - and perhaps equidistant - grid of height points it is not recommended to use this feature. Do not use this feature just because the resulting contour lines can be interpreted easier visually on the screen or because it may be easier to „imagine“ the terrain model. Depending on the settings used for the grid appearance, option „Level Range“ (see chapter 5.3.2), a more or less fine grid of lines of equal height is generated. These lines are generated by linear interpolation from the heights of the existing height points and are displayed as grid contours („Lines of Equal Sound Level“) is displayed, which are afterwards converted into terrain contours. CadnaA - Reference Manual Application 4 52 4 Procedure Chapter 4 - Topography 4.3.3 Generate Terrain Contours from Height Points Initially, there is a file with height points. 4 Terrain model from non-uniformly distributed height points Proceed as follows: • Specify the receiver spacing on the dialog Grid|Specification (in this example: 10 * 10 m). At these grid points the terrain height is calculated using the height data of the height points. • The receiver spacing affects the accuracy of the interpolation, since intermediate values (between the height points) are interpolated linearly. A very fine spacing is not useful with respect to the resulting file size, on the other hand, it would fake a higher accuracy of the terrain model than had the original data. Select from the list box of parameters on the toolbar of the CadnaA main window the option „Ground“. CadnaA - Reference Manual Chapter 4 - Topography 4.3.3 Generate Terrain Contours from Height Points 4 53 At present, no ground grid existent, the ground grid is empty. • Start the grid calculation via the command Calc Grid on the Grid menu. The ground grid is displayed using the current appearance settings for the evaluation parameter „Ground“. In addition, in the right corner of the status bar the ground height is displayed at the location of the mouse pointer („G: xxx.xx“ m, with G for „Ground“) . • By moving the mouse across the grid area, study the value range of heights on the grid. • Open the dialog Grid|Appearance and enter in the dialog range „Level Range“ the lower and upper limits and the class width of the height range of the ground grid. • Select the display option „Lines of Equal Sound Level“. In this case, the values for lower and upper limit and for class width represent heights (in meters) and not sound levels. Thus, the isolines are lines of equal height. • Select a suitable color palette (see chapter 12.6.1) . Please note that the color palette selected for the evaluation parameter „Ground“ is not relevant when generating the contour lines. Always the values for „Level Range“ are used - even if disabled. In order to display the interpolated ground heights at the grid points proceed as follows: • If necessary, reopen dialog Grid|Appearance. • Select for „Grid Points“ the option „Values. After closing the dialog with OK, the ground heights at the grid points are displayed. If necessary, change the scale using the zoom tool to be able to read the values. CadnaA - Reference Manual 4 54 4 Chapter 4 - Topography 4.3.3 Generate Terrain Contours from Height Points 4 Ground grid with lines of equal height having a vertical difference of 1 m (display range: lower/upper limit: 80/120 m, class width: 1 m) Height points with interpolated grid of the ground height showing the ground height in m at grid points (10x10 m spacing) CadnaA - Reference Manual Chapter 4 - Topography 4.3.3 Generate Terrain Contours from Height Points 4 55 Now, the contour lines are then generated from the displayed grid lines: • To this end, press the key combination ALT+F12. 4 • Confirm the prompt with OK. The lines of equal height are converted to the object type „Contour Line“. • Select on dialog Grid|Appearnce the option „No Grid“ to no longer display the grid. • Disable the height points to just display the contour lines. New terrain model based on contour lines CadnaA - Reference Manual 56 4 4 Chapter 4 - Topography 4.3.3 Generate Terrain Contours from Height Points When generating the lines of equal height the height at the corners of the limits (see chapter 9.1) is considered as well. This means that the resulting heights near the corners of the interpolated area are possibly not valid because there is no valid height at those points (e.g. too few height points). Therefore, if necessary, the contour lines generated in these areas need to be cut or deleted. In the above example this applies to the north-west corner of the limits (upper left corner). In the corner area there are no height points. Consequently, the resulting height in this area is defined by the distance and the height of the corners of the limits (option „Standard Height“, see chapter 6.2.6). The triangulation ranges from the limit‘s corners to the nearest height defining object. This means that the height in this area is at random and therefore not relevant. Enter a closed polygon that delimits the project area to get deleted from the one not to be deleted. Select from the context menu of that polygon the command Break Lines (see chapter 11.25 in the manual „Introduction to CadnaA“) in order to cut the terrain contours. By selecting the command Modify Objects from the context menu of that polygon the contour lines outside can be deleted. CadnaA - Reference Manual 4 57 Chapter 4 - Topography 4.3.4 Generate a Grid of Height Points from Terrain Contours 4.3.4 Generate a Grid of Height Points from Terrain Contours This software feature enables to convert a terrain model made from a contour lines into a grid of equidistant height points. Depending on the spacing of height points, the terrain model can be simplified and reduced in size (regarding the RAM required). Application 4 Note again that the procedure described in the following may not be useful and functional in any case. The decision on the application is with the user. Initially, there is a file with contour lines. Terrain model from contour lines: The area in the upper right corner is supposed to be invalid since the triangulation occurs from the last contour line to the limit‘s corner (considering the local height at the corner). CadnaA - Reference Manual Procedure 58 4 Chapter 4 - Topography 4.3.4 Generate a Grid of Height Points from Terrain Contours Proceed as follows: 4 • Open the CadnaA file with the terrain model based on contour lines. • Recalculate the limits wrap-around (via menu Options|Limits, „New“) • Close the dialog Limits by OK. The recalculation of the limits intends to restrict the project area to the area of the contour lines. Since the terrain is triangulated including the limit‘s corners, the terrain height outside the area covered by contour lines is usually invalid. Consider that despite the recalculation of the limits, there may still exist „invalid“ areas, especially with terrain models having an irregular boundary. • Select the point source from the toolbox and place it at the lower left corner of the terrain model. • Double-click the point source and click the „Geometry“ button. • Enter the x and y coordinates. • In order to generate an equidistant grid of height points, it is recommended to enter integer values. Of course, this is not mandatory. Enter still a relative height of zero and check that the option „Calculate from DTM“ is selected. Point geometry with (x, y, z) = (5, 5, 0) m CadnaA - Reference Manual Chapter 4 - Topography 4.3.4 Generate a Grid of Height Points from Terrain Contours • Close both dialogs with OK. • Select from the context menu of the point source the command Duplicate. • Calculate from the side lengths of the limits and the intended distance of height points the number of points in x and y directions. Example: The limits have side lengths of 4 km by 4 km. With a spacing between points of 10 m, this results in 4000/10 = 400 points in each direction (including the original point source). • Enter on the Duplicate dialog the calculated number of points and the distance between the centers. Dialog Duplicate • Select from the context menu of a contour the command 3D-Special to update the terrain heights in the geometry of the point sources. • Open the dialog Geometry of a point source to check for the actual ground height. CadnaA - Reference Manual 4 59 4 60 4 Chapter 4 - Topography 4.3.4 Generate a Grid of Height Points from Terrain Contours 4 Example: The ground height calculated from the terrain model at this point is 192 m. • Click with the right mouse button in an empty area of the screen (or into the gray area outside of the limits). • Select the action "Convert to" for the object typ "Point Source" and click OK. • Select the following dialog Convert Objects the target object type „Height Point“. Dialog Convert Objects, here to height points • Click OK and confirm with "All". Subsequently, the point sources are converted to height points while maintaining their geometry data. The height of the height points results from the sum (ground height + relative height) of the point sources. Since the relative heights are zero, the z height of the height points correspond to the height calculated from the terrain model of contour lines. • Disable or delete the contour lines via the dialog Modify Objects. CadnaA - Reference Manual Chapter 4 - Topography 4.3.4 Generate a Grid of Height Points from Terrain Contours 4 61 4 Example: terrain model with contour lines and height points, spacing of points (10 by 10) m (before deactivating/deleting the contour lines) Example: A terrain model from height points having a spacing of 10 m by 10 m. The terrain profile in the foreground is a result of the triangulation to the limit‘s corners and must, therefore, be regarded as invalid. CadnaA - Reference Manual 62 4 Chapter 4 - Topography 4.3.4 Generate a Grid of Height Points from Terrain Contours 4 CadnaA - Reference Manual Chapter 4 - Topography 4.3.5 Generate Cluster of Heights Points from Bitmap 4.3.5 4 63 Generate Cluster of Heights Points from Bitmap When terrain height data is provided using a (geo-referenced) gray-scale bitmap ("GeoTIFF"), this data can be converted into clusters of height points. The gray-scale bitmap may have a resolution of up to 16 bit. Gray-scale bitmap with a resolution of 8 bits can represent 28 = 256 steps in height only! Colored bitmaps can not be used with this feature. • Load the bitmap using the specific functions for the import of bitmaps (see chapter 10.1 "Insert Bitmaps"). • Click with the right mouse button into the white area of the CadnaA main window and select the command Modify Objects from the context menu. • Select the action „Convert to“ for the object „Bitmap“ and click OK. • On the dialog Convert to just the target object type „Contour Line“ is available. • Confirm the prompt with OK. The bitmap is converted into contour lines being clusters of height points (see chapter 4.1.2 "Height Point", section "Use Contour line as Cluster of Height Points"). CadnaA - Reference Manual 4 64 4 Chapter 4 - Topography 4.3.5 Generate Cluster of Heights Points from Bitmap 4 CadnaA - Reference Manual Chapter 5 - Immissions 51 Chapter 5 - Immissions For the calculation and the evaluation of receiver levels the following objects are available in CadnaA: • receiver point (see chapter 5.1), • area of designated land use (see chapter 5.2), • calculation area or horizontal grid (see chapter 5.3), • vertical grid (see chapter 5.3.6), • building evaluation (see chapter 5.4). Furthermore, this chapter explains the evaluation features available within the CadnaA-option XL (see Chapter 15 - Options X & XL). CadnaA - Reference Manual 5 2 5 Chapter 5 - Immissions 5 CadnaA - Reference Manual Chapter 5 - Immissions 5.1 Receiver 5.1 53 Receiver Receiver points are distinct locations where the sound level is calculated. The level calculation for receivers is started either via the command Calc on the Calculation menu or by clicking the pocket calculator symbol toolbar. on the After calculation select the respective evaluation parameter from the list box on the toolbar top display the results in the graphics. Compared to grid calculations (see chapter 5.3) the partial levels are stored for all receiver points. Moreover, a detailed calculation protocol can be produced for receiver points showing all relevant intermediate values (see chapter 6.5 Calculation Protocol). For receivers, the acoustic rays can be displayed up to the selected order of reflection provided the option „Generate Rays“ has been activated on the dialog Receiver prior to the calculation. Dialog Receiver CadnaA - Reference Manual 5 4 5 Land Use/Standard Value Chapter 5 - Immissions 5.1 Receiver When a limiting level or standard level is specified on the dialog Receiver (either by selection of a type of land use or entering values) it can be evaluated after a calculation right from the graphics whether this level has been respected or exceeded. In case of excess the receiver point is displayed in red on the graphics. 5 The color being used for receivers can alternatively be defined via dialog Appearance using a formula. Specifying Limiting Values Limiting levels or standard levels can be specified in two ways. Option "Land Use" By default, the option "Determine from Areas of Land Use" is activated. In this case, the limiting or standard levels result from the type of land use and the selected type of noise ("Use Standard Levels for"). The types of land use are defined on the menu Options|Land Use (see chapter 5.2.1). When the option "Determine from Areas of Land Use" is deactivated a type of land use can be selected locally. After calculation, the respective limiting or standard level is displayed. Option "Standard Value" When this option is selected a limiting or standard value for each evaluation parameter can be entered directly. Sound Pressure Level Here the receiver level for each evaluation parameter specified is displayed (see chapter 6.2.5). Either the selection „Type“ or the input for „Name“ is used as a designation depending whether option „Name“ has been activated or not. Excess Level Here the excess level value for each evaluation parameter is displayed. Per default, the receiver symbol in the graphics changes to red if the limiting value is exceeded for the selected evaluation parameter. Alternatively, a different color may be used in a formula (see chapter 9.5). CadnaA - Reference Manual 55 Chapter 5 - Immissions 5.1 Receiver If this option is activated prior to the calculation at receivers the sound rays up to the selected order of reflection are displayed using auxiliary polygons (see also chapter 6.1.7 "Displaying Sound Rays"). The ID of the auxiliary polygons shows the partial level for the first evaluation parameter and the reflection order. Option "Generate Rays (as Aux. Polygons)" In case the first evaluation parameter is a mixed level (e.g. Lden) the displayed of Ld in the ray/s is enforced. 5 The rays are deleted after having deactivated this option and recalculation. components of the polygon’s ID: • RAY: identification as a ray • 660: partial level Day 66.0 dB(A) • 00: direct path (0th order) components of the polygon’s ID: • RAY: identification as a ray • 414: partial level Day 41.4 dB(A) • 01S: ray 1st order, S: screened (i.e. ray is diffracted by at least one obstacle) This button appears only when a calculation protocol was generated (see chapter 6.5). The subsequent dialog Protocol shows the calculation results per ray. In case the option „Minimum Value for Lr“ is activated (see chapter 6.4), this will be ignored here. CadnaA - Reference Manual Dialog Aux. Polygon, button „Protocol“ 6 5 Chapter 5 - Immissions 5.1 Receiver Level Spectrum (dB) 5 Since the rays are auxiliary polygons they are not shown on 3D-Special view by default (see chapter 9.5.8). Activate the option „Show in 3D“ on the „3D“ tab of the object type „Aux. Polygon“ (see chapter 9.5) to display them. When the emission of sources is specified by spectra the dialog Receiver gets expanded in order to display the resulting octave level spectrum for the selected evaluation parameters. dialog Receiver (type: spectrum in octave bands) dialog Receiver (type: spectrum in octave and third-octave bands) Note the following remarks regarding the displayed octave or third-octave level spectrum/spectra: • The displayed A-weighted receiver level/s contains the partial levels of all emission types: those of the sources with A-weighted emission, as well as those with an emission spectrum in octaves or in third-octaves bands. • The octave level spectrum/spectra displayed contains the partial levels of all sources with an emission spectrum in octaves or in third-octaves. CadnaA - Reference Manual 57 Chapter 5 - Immissions 5.1 Receiver • The third-octave level spectrum/spectra displayed contains the partial levels of the sources with an emission spectrum in thirds-octaves only. (see also table below) emission type source ... is included in ... A-weighted receiver level spectrum in octave bands spectrum in third-octave bands A-weighted emission + - - emission in octave bands + + - emission in third-octave bands + + + • When a level in an octave band of a single active source is missing, this frequency band will not be displayed on table "Level Spectrum". • The weighting for octave bands can be specified via menu Options|Miscellaneous (see chapter 6.7). 5 see chapter 4.2 Button „Geometry“ Clicking this button displays the A-weighted partial levels or the octave level spectra of all sources contributing to the level at this specific receiver in the table Partial Level (see chapter 5.1.2). Button "Partial Level" Partial levels are not displayed in third-octave bands, even when such sources are present and activated. In addition, the table Partial Level on the Tables menu shows all Aweighted partial levels for all receiver points. CadnaA - Reference Manual 8 5 Chapter 5 - Immissions 5.1 Receiver Button "AzB-Level" This button is available with option FLG only. Entering receivers at a building’s facade In order to enter receivers at a distinct distance from a building’s facade, select the command Object Snap on the menu Options (see chapter 9.3). The default distance is 0,05 m. The generate receiver points for multiple storeys use the command Generate Floors (see chapter 11.18 in manual „Introduction to CadnaA“). 5 Specifying the Precision of Levels By default, the receiver levels are displayed with a precision of one decimal. This can be changed via the CadnaA INI-file. Proceed as follows: • Close all CadnaA-main windows. • Open the file CADNAA.INI and enter in section [Main] the following text line: dBOutPrec=X (with X: number of decimals). Regarding the location of the CadnaA INI-file see chapter 2.1 "Installing CadnaA" in the manual „Introduction to CadnaA“. This setting is relevant for dialog Receiver and for the table Partial Level. Dialog Receiver: Level with a precision of 2 decimals CadnaA - Reference Manual Chapter 5 - Immissions 5.1.1 Consistency Check 5.1.1 59 Consistency Check Prior to the calculation of noise levels at receivers and/or prior to the grid calculation several input data is checked for consistency automatically. The consistency check includes: • at receivers: object inside a building • at point, line, and area sources: object inside a building • at point, line, and area sources: no emission value The objects type and its name are displayed on the dialog Consistency Check. Result of a Consistency Check: Point Sources inside Buildings CadnaA - Reference Manual 5 10 5 Chapter 5 - Immissions 5.1.1 Consistency Check Dialog Options 5 Highlighting an Object By a single mouse click into a line of the table the respective object is highlighted in the graphics. Editing of Objects For editing double-click in a line of the list. This opens the respective object dialog. Alternatively, marking of a line can and clicking the button "Edit" opens the dialog as well. Synchronize Graphic Clicking this button centers the selected object on the screen. Alternatively, click into a line while holding the SHIFT-key depressed. Button "Continue" continues with the calculation Button "Cancel" terminates the calculation Attribute CONS_CHECK This attribute is set (CONS_CHECK= 1) for all objects been displayed or indexed within the consistency check upon calculation. If not indexed CONS_CHECK = 0. Subsequently, this attribute can be used - for example - to deactivate the objects being displayed within the consistency check: CadnaA - Reference Manual 5 11 Chapter 5 - Immissions 5.1.2 Partial Levels 5.1.2 Partial Levels Clicking the button „Partial Level“ on the dialog Receiver opens the table Partial Level. With several variants (see chapter 14.2), the partial levels are displayed just for the variant most recently calculated. 5 List of partial levels at a receiver with all noise sources and for all evaluation parameters The list of partial levels displays for the currently selected receiver the Aweighted partial level and the linear or A-, B-, C- or D-weighted octave spectra for the evaluation parameters defined and for all sound sources considered in the calculation. The weighting for octave bands can be specified via menu Options|Miscellaneous (see chapter 6.7). Partial Level Receiver Select the Sort Column (see chapter 11.1.4) command from the context menu to have the columns sorted by, e.g., partial levels in ascending order. Double-clicking the cell of the receiver point opens the edit dialog of the source with this partial level. Sort Column CadnaA - Reference Manual 12 5 5 Chapter 5 - Immissions 5.1.2 Partial Levels Overall Partial Levels Selecting the menu Tables|Partial Levels opens an overall list of the partial levels at all receiver points caused by all sources considered in the calculation. Group On menu Tables|Groups, the partial levels of all noise sources which belong to the group are displayed (see chapter 14.3). Variants In case several variants (see chapter 14.2) are defined and active, the partial levels are displayed for the variant most recently calculated only. Performance Parameters with no Partial Levels For the following evaluation parameters no partial levels are displayed (neither on table Partial Level for a receiver, nor on table via Tables| Partial Level menu): Suppress Display of empty Table Lines • standard deviations Sigma D/E/N • loudest hourly level L1hMaxD/E/N • equation =f(x) The display of "empty" lines in the table Partial Level can be suppressed by a corresponding entry in the file CADNAA.INI. Add in section [Main] the following line to achieve this: NoEmptyPartLev=1 With that value being 1 no „empty“ spectra will be displayed. „Empty“ spectra result from sources outside of the search radius or from sources been excluded from the calculation due to a maximum error specified. Irrespective of this setting, the partial levels of all sources will be displayed on dialog ObjectTree|Partial Level and on table Partial Level on the Tables menu. CadnaA - Reference Manual Chapter 5 - Immissions 5.2 Area of Designated Land Use 5.2 5 13 Area of Designated Land Use Areas of different land use allow for the description of the designated land use in accordance with the Land Use Ordinance. Points within such areas can thus be assigned the standard levels for the different types of noise (menu Options|Land Use). This feature allows you to adopt the types of designated land use for the entire CadnaA project directly from development plans, and to calculate sensitivity maps. This leads to conflicting maps where the differences between the rating levels calculated for each type of noise and the standard levels, as per the designated land use, are calculated (requires option X or XL). CadnaA can also automatically assign the pertinent standard levels to all receiver points lying within a defined area of land use. The prerequisites are 1. that the check box „Determine from Areas of Land Use“ is activated in the edit dialog of the receiver point and 2. an area of designated land use is inserted in which the receiver points are included. Enter the borderlines of the areas of designated land use after clicking the icon on tool box. In the edit mode double-click the borderline of the inserted area and select the type of land use from the list box. CadnaA - Reference Manual 5 14 5 Chapter 5 - Immissions 5.2 Area of Designated Land Use Population / km² (requires X or XL option) - The menu command Grid|Population Density allows CadnaA to approximate the population density from the buildings, and to assign it to the areas of designated land use (see chapter 15.4). Monetary Data (requires X or XL option) - A technique to evaluate the noise is described in the Swiss BUWAL study /88/. This method is implemented in CadnaA (see chapter 15.5). 5 CadnaA - Reference Manual 5 15 Chapter 5 - Immissions 5.2.1 Type of Land Use 5.2.1 Type of Land Use Via the menu Options|Land Use, the standard levels for the defined evaluation parameters (see chapter 6.2.5) applying to the different types of noise and the appearance - filling pattern and color - are assigned to the different types of land use. These different kinds of land use can be selected in the edit dialog of the object Area of Designated Land Use (see chapter 5.2). 5 Via this dialog new types of land use areas can be defined. • Select a blank line in the Land Use table. Just click the white area. • Then enter a name and the pertinent standard levels in the boxes. By default, the first item on the list of land uses is reserved for the type „(ohne Nutzung)“ (i.e. „without/no use“). The position of this first item shall no be altered for reason of correct assignment. Land Use „(ohne Nutzung)“ Colors, line style, and filling pattern for representation of the area can then be selected as customary after clicking the color button. Colors, Line Style, and Fill In practical work it will be useful to switch off the filling pattern of areas with a certain land use for the clarity of the colored noise maps. User-defined types of land use are saved with the project. They are not available for other projects. CadnaA - Reference Manual 16 5 Chapter 5 - Immissions 5.2.1 Type of Land Use 5 CadnaA - Reference Manual 5 17 Chapter 5 - Immissions 5.3 Receiver Grid 5.3 Receiver Grid On the menu Grid the following features are available: • specifying the spacing and the height of grid points (see chapter 5.3.1), • launching grid calculations (see chapter 5.3.3) for up to 16 variants (see chapter 14.2) and for up to four evaluation parameters (plus the ground grid, see chapter 6.2.5), • selecting the type of appearance of the grid/noise map (e.g. as lines or areas of equal sound levels, see chapter 5.3.2), • commands to open, save, delete, compress/decompress and to resample grids. 5 The grid calculation for the specified evaluation parameters and the defined grid spacing is launched by the command Calc Grid (see chapter 5.3.3). Calc Grid Selects the grid for the corresponding evaluation parameter from the list box on the toolbar on the CadnaA main dialog. Select Evaluation Parameter CadnaA - Reference Manual 18 5 5 Chapter 5 - Immissions 5.3 Receiver Grid Grid|Open With the command Grid|Open a saved grid can be loaded into the present file. Select the corresponding file via the dialog. Using multiple selections several grid files can be loaded at once. A grid cannot be loaded via the command File|Import. different Evaluation Parameters In case a grid file contains several grids with different evaluation parameters they will only be displayed if the same evaluation parameters also exist in the current file. Grid Formats Following grid formats can be opened: • • • • • • • • option „Keep Current Grid“ CadnaA-grid (*.cnr) and CadnaA-files (*.cna) ESRI ASCII-grid (*.asc, *.hdr, *.flt): Both, non-proprietary ASCII raster files (*. asc) as well as proprietary binary raster files (*.hdr, *.flt) are imported. ASCII-grid (*.rst) LimA grid (*.ert) SoundPLAN grid (rlk_.*;*.gm) Immi grid (*.ird) AUSTAL grid (*.dmna) NMGF grid (*.grd, from NMPlot, TNM, INM) When the option „Keep Current Grid“ is activated you can load grids in the current file without deleting the existing ones. The first existing calculated grid in the current file sets the mash of the grid. With different grid spacings of the present and the loaded grids, the resulting grid will be adjusted to the original by interpolation. This function enables the calculation of a large file using several calculation areas on different computers sharing the file by calculating only one of the calculation areas one after the other. Afterwards all the grids will be merged into the original file via command Grid|Load with the option „Keep Current Grid“ activated (see chapter 6.10 "PCSP - Program Controlled Segmented Processing"). CadnaA - Reference Manual 5 19 Chapter 5 - Immissions 5.3 Receiver Grid With the command Grid|Save as only the calculated grids will be saved, so not the object data. The following file formats are available: • • • • Save Grid as CadnaA-Grids (*.cnr) ASCII-Grids (*.rst) LimA Grids (*.ert) and NMGF Grids (*.grd). When saving to an ASCII grid the evaluation parameters as entered or edited will be used as a designation (see dialog Configuration, Evaluation Parameters Tab). 5 Furthermore, grid data can be exported as lines or areas or as an ASCII file for ArcView (see chapter 13.3.2 "ArcView (*.shp)"). Text file with ASCII-grid data for 4 evaluation parameters (format *.rst) By the command Grid|Delete the existing grid (for up to four evaluation parameters, plus the ground grid) is deleted and from the file (upon Save). This command cannot be undone. Grid|Delete When deleting a grid, the settings for the grid spacing and for the grid appearance are kept. However, when selecting the command Grid|Delete while keeping the SHIFT key depressed restores the default settings for grid spacing and grid appearance. Selecting the command Grid|Delete while keeping the CTRL key depressed will delete - after having confirmed a prompt - all grids in all variants. CadnaA - Reference Manual Delete Grids in Variants 20 5 Grid|Compress, Decompress Chapter 5 - Immissions 5.3 Receiver Grid By the command Compress on the Grid menu grids resulting from former CadnaA releases can be compressed in order to reduce their volume. By contrast, the raster data from files created with CadnaA release 4.3 or later will be compressed automatically upon calculation. The command Decompress enables to decompress the raster data resulting from releases starting from 4.3. Decompressing grids is required when grids having different calculation areas shall be combined (see chapter 5.3.4 "Grid Arithmetic"). 5 Additional Information The background of these two commands is the requirement to further reduce the disk space required for large-scale grids, in particular. This is advantageous when loading, storing and calculating grids. In CadnaA, prior to release 4.3, the grid area saved at tilted calculation areas was given by the smallest enveloping rectangle. In fact, the grid area always represented a rectangular section within the limits whose edges were parallel to the coordinate axes xy. Starting from CadnaA release 4.3 just those grid points are saved which are distinctively located inside the calculation area(s), thus causing a compression of the grid when being saved. CadnaA - Reference Manual 5 21 Chapter 5 - Immissions 5.3 Receiver Grid The example below shows a tilted calculation area. When saving the grid with a release version prior to 4.3 all the points within the left red rectangle have been saved. This also comprises the grid points which are located outside the calculation area. Example In contrary, the right red rectangle delimits the grid area, which is stored starting from release 4.3. This area corresponds to the calculation area. 5 Saving of Grid Data prior to release 4.3 CadnaA - Reference Manual Saving of Grid Data from release 4.3 on 22 5 Grid|Resample 5 Chapter 5 - Immissions 5.3 Receiver Grid The command Resample offers to interpolate a grid with a given receiver spacing into a new grid with a different receiver spacing. Dialog Resample Grid On the dialog Resample Grid enter the new receiver spacings dx and dy. After clicking OK, the resampling is processed. Resampling is possible starting from a coarser grid (larger receiver spacing) to a finer grid, but also starting from a finer grid (smaller receiver spacing) to a coarser one. Note that in particular when resampling a coarser to a finer grid the intermediate grid points are generated using linear interpolation. Moreover, by „upsampling“ and then “down-sampling“ - obviously - the initial grid cannot not be regained. Application Resampling may be used in conjunction with grid arithmetics (see chapter 5.3.4) when rearranging several input grids with different receiver spacings to a common resulting grid. CadnaA - Reference Manual 5 23 Chapter 5 - Immissions 5.3 Receiver Grid (displaying the grid points as dots) Example initial grid (10 x 10) m 5 initial grid resampled to (2.5 x 2.5) m receiver spacing initial grid resampled to (50 x 50) m receiver spacing CadnaA - Reference Manual 24 5 Chapter 5 - Immissions 5.3 Receiver Grid resampled grid (50 x 50) m again resampled to (2.5 x 2.5) m receiver spacing 5 The valid grid size has reduced because - due to the resampling to (50 x 50) m spacing - a part of the grid no longer exists (i.e. lying outside the calculation area). CadnaA - Reference Manual 5 25 Chapter 5 - Immissions 5.3.1 Grid Specification 5.3.1 Grid Specification On this dialog the distance between grid points in x and y direction and the receiver height in meters is specified. By default, a spacing of dx=dx=10 m and a receiver height of 4 m is used. Grid Spacing and Height A smaller grid spacing results in a higher density of grid points which enhances the contours in the graphics of the lines or areas of equal sound level. On the other hand, a finer grid requires more calculation time. By default, the grid height is relative with respect to the ground level. In order to calculate using an absolute grid height, activate this option. In this case, the grid does not follow the terrain’s shape. This will case that grid points below terrain are ignored in the calculation. 5 absolute Grid Height Dialog Receiver Grid with optional features Both options are activated by default. In this case, no grid points are placed into the horizontal projections of sound sources and buildings. Consequently, no level is calculated at those grid points. CadnaA - Reference Manual Option „Exclude Sound Sources/Buildings“ 26 5 Chapter 5 - Immissions 5.3.1 Grid Specification Option „Use Height of Buildings“ By activating this option in addition to the option „Exclude Buildings“, the horizontal projection of a building is excluded from the grid if the building height exceeds the grid’s height. By default, this option is deactivated. for all Variants When more than a single variant (see chapter 14.2) is used, this option is activated by default. In this case, all active variants make use of the same grid spacing. By deactivating this option for a variant and by entering a different grid spacing dx|dy, this option gets automatically disabled by CadnaA for all other active variants. For these variants, however, the grid spacing itself remains unchanged. 5 In case this option is deactivated (for one or for all variants) and the grid spacing matches for all active variants, the option is activated by CadnaA for all variants automatically. Button „Options“ Option „Define Grid over entire Limits“ With this option activated the grid covers the entire defined limits of the project file (see dialog Options|Limits), provided no calculation areas have been defined. With this option deactivated, the calculation area can be restricted bey entering the x and y coordinates for the bottom left and the upper right corners of the grid. Alternatively, a calculation area can be used to restrict the grid’s area (see chapter 6.4 "Selecting Data for the Calculation"). CadnaA - Reference Manual 5 27 Chapter 5 - Immissions 5.3.1 Grid Specification In this example, building 1 has a height of 10 meters and building 2, a height of 3 m. The grid’s height is at 4 m. Example • Load the addressed file. Examples\ • Activate on dialog Receiver Grid the options „Exclude Buildings“ and „Use Height of Building“. • Set on the dialog Options|Appearance the fill of the buildings to „transparent“. • In order to achieve this, select any type of hatching first and make sure that the option „transparent“ is activated. • Deactivate on dialog Calculation|Configuration, „General“ tab, the option „Extrapolate Grid ’under’ Buildings“. This will prevent the lines are the areas of equal level to reach to the inside of the building’s borders. • Start the grid calculation (e.g. for a grid spacing of 1 by 1 m). CadnaA - Reference Manual 05_Immissions\Use Height of Buildings.cna 5 28 5 Chapter 5 - Immissions 5.3.1 Grid Specification The following graphic results: 5 Grid after calculation at a height of 4 m with activated option „Use Height of Buildings“, building 2 is covered by the grid’s lines of equal sound level CadnaA - Reference Manual 5 29 Chapter 5 - Immissions 5.3.1 Grid Specification The command Delete Grid Points from the context menu of a calculation area is useful to „cut out“ calculated noise maps either to replace that portion after a new calculation or to use only a section of a big noise map. The PCmemory used for the deleted section of the grid will be released. Delete Grid Points 5 total grid area (white framed area: calculation area inside the present grid area By selecting the command from the context menu of the inner calculation area the grid points inside are deleted. recalculated grid using LmE,D/N+ 3 dB in the inner calculation area total grid imported by Grid Open with option „Keep Current Grid“ activated Insert an arbitrarily shaped calculation area over a calculated noise map, highlight the polygon and select Delete Grid Points from the context menu. Select either inside or outside the polygon. The settings of the current grid will be assigned to the imported grid. CadnaA - Reference Manual 30 5 Chapter 5 - Immissions 5.3.1 Grid Specification 5 CadnaA - Reference Manual Chapter 5 - Immissions 5.3.2 Grid Appearance 5.3.2 5 31 Grid Appearance Via the dialog Appearance on the Grid menu the settings for displaying grid results are defined. The dialog comprises of the following sections: • • • section „Show“: selection of display mode section „Color Palettes“: selection of color palettes, globally for all evaluation parameters or individually for each evaluation parameter. Level Range and Line Width: This section corresponds with the options available in former releases of CadnaA. The display options resulting from former CadnaA files will be displayed for color palette „(file)“. When using color palettes, it is recommended to deactivate the option „Level Range“. Dialog Grid Appearance CadnaA - Reference Manual 5 32 5 Button „Apply“ Chapter 5 - Immissions 5.3.2 Grid Appearance When clicking the button „Apply“ the modifications are applied to the main window immediately while keeping the dialog open. Show ... Lines of Equal Sound Level With this option the lines of equal sound level are displayed on the grid. The value range and the class width (and all further settings) result from the select color palette/s. The grid caption results from the specification for „Single Value“ of the selected color palette (see chapter 12.4 "Symbol Library"). Areas of Equal Sound Level With this option the areas of equal sound level are displayed on the grid. The value range and the class width (and all further settings) result from the selected color palette/s. The grid caption results from the specification for „Interval“ of the selected color palette (see chapter 12.4 "Symbol Library"). 5 In either case, the boundaries are interpolated (by linear interpolation). With the option „Exclude Sound Sources/Buildings“ (see chapter 5.3.1 "Grid Specification") activated, uncolored areas in the vicinity of buildings or area sources may result, depending on the spacing of receiver point. In order to avoid this, the option „Extrapolate Grid under Buildings“ on menu Calculation|Configuration is activated by default (see chapter 6.2.2 "General Tab"). In this case, the colored areas of the grid start from the object’s boundaries. Raster, Oversampling When the oversampling is set to 1 (default value) the representation applies the resolution of the specified receiver spacing (see chapter 5.3.1 "Grid Specification"). With an oversampling of larger than 1 intermediate grid points are generated additionally. The sound level at those intermediate points is determined by linear interpolation. No Grid With this option no noise map is displayed on the graphics (2D-view). Nevertheless, on the 3D-Special view the colored grid is still displayed. To avoid this, switch to the option „Ground“ from the list box on the toolbar of the main dialog. This will cause the no grid being displayed on the 3D-Special view. CadnaA - Reference Manual 5 33 Chapter 5 - Immissions 5.3.2 Grid Appearance On the dialog section „Color Palettes“ the color palettes for up to four evaluation parameters and for the ground grid are selected. With the default setting, the color palette selected for evaluation parameter 1 is applied to all further evaluation parameters and the ground grid. To select a color palette for each evaluation parameter and the ground grid activate the respective check box. Color Palettes 5 Dialog Grid Appearance, section „Color Palettes“ By default, the color palette „(default)“ is preselected for all grids. The default color palette corresponds with the formerly used grid appearance settings, with respect to the type of grid shown (Raster, Oversampling 1) and the level range. Color Palette „default“ When loading a file which has been generated using a former version of CadnaA the settings on dialog Grid Appearance will be displayed for the color palette „(file)“. The color palette „(file)“ is stored in the local library of color palettes (see chapter 12.6). Color Palette „file“ After activation of the check box, color palettes from the local library can be selected from the list box for each evaluation parameter. The text displayed on the list box is the ID-code of the respective color palette in the local library. Selecting Color Palettes Color palettes from the global library are selected by clicking the file selection symbol. SHIFT-clicking on the file selection symbol opens the local library of color palettes. CadnaA - Reference Manual 34 5 Chapter 5 - Immissions 5.3.2 Grid Appearance Examples The palette „pal_35_85_step_5“ is used for all four evaluation parameters (if any) and the ground grid. 5 The palette „pal_35_85_step_5“ is used for evaluation parameters 1, 2, 4 and for the ground grid. For evaluation parameter 3 the palette „pal_0_20_step_2“ is used. Compared to the last setting, now the default color palette is used for the second evaluation parameter. For evaluation parameter 3 and for the ground grid the palette „pal_35_85_step_5“ is still used. When loading a file from a former release of CadnaA, the color palette „(file)“ resulting from this file is used for all evaluation parameters and for the ground grid. REMARK: In this case, the grid appearance corresponds with the appearance in former CadnaAreleases. CadnaA - Reference Manual 5 35 Chapter 5 - Immissions 5.3.2 Grid Appearance This option may have three modes: deactivated (no tick mark), activated (black tick mark), neutral (grey tick mark). In the neutral mode (default setting) the setting for „Progressive Color“ of the respective color palette applies. Thus, if a progressive color has been defined in the color palette it will be used, and vice versa. With this option deactivated, color palettes with progressive colors show use distinct color with transition. With this option activated, color palettes without progressive colors show them, instead. Progressive Colors The option „Grid Points“ enables to mark the locations on the grid where the level has been calculated (selection „Dots“) or of the calculated levels at those locations (selection „Values“). Grid Points When displaying the terrain’s height (see chapter 4.5) the height in meters is displayed with the option „Values“ selected. The same holds for attribute values resulting from ObjectScan (see chapter 15.1). When loading a file created by a former release of CadnaA, the dialog Grid Appearance displays the grid settings for the color palette „(file)“. The lines and areas of equal sound level include - as it was the case with former releases of CadnaA - the upper limit of every value range (i.e the option „Interval Border to Lower Interval (lo < xxx <= hi)“ is activated, see chapter 12.6 "Color Palettes"). Level Range The value in this box will just have an effect if either the option „Lines of Equal Sound Level“ or „Areas of Equal Sound Level“ is activated. The class width defines the width between adjacent lines of equal sound level. Class Width The lower and upper limits define the level range. Lower/Upper Limit The option „Level Range“ should nowadays not be used when defining the grid appearance as it disables the selected color palettes. CadnaA - Reference Manual 5 36 5 Chapter 5 - Immissions 5.3.2 Grid Appearance The grid captions as being defined can be inserted into the graphics and be printed via the Plot-Designer by use of the object „Symbol“ (see chapter 9.11.3 "Symbol" and chapter 13.1.2 "PlotDesigner - Cell Types"). Furthermore, a grid caption can be added even to the 3D-Special view (see chapter 9.14.1,). Line Width 5 Provided the display mode „Lines of Equal Sound Level“ is selected, noise contours can be highlighted by thicker lines in intervals. For example, in order to draw a thicker line in steps of 10 dB, activate the first option „Line Width“ and select „??0.0" from the list box. Here, the question marks serve as wild cards for any other figure. In order to draw a thicker line in steps of 5 dB in addition, activate the second option „Line Width“ and select „??5.0" from the list box. The line widths are specified in tenths of millimeters (mm/ 10). Import of old PaletteFiles As already with the level range, the option „Line Width“ is only used to display grid appearance settings resulting from former CadnaA files. Nowadays, the definition of the line width for each value range is part of the color palette. The button „Import old Palette-File“ enables to load files with color palettes (file extension *.PAL) from former CadnaA releases. The imported color palette is shown on the list box for the evaluation parameter 1 and simultaneously copied to the local library. This feature can be used to import an arbitrary number of existing color palettes to the local library by multiple import. CadnaA - Reference Manual 5 37 Chapter 5 - Immissions 5.3.2 Grid Appearance This option is enabled by default. In this case, the same settings for the grid appearance are used for all active variants (see chapter 14.2). Option „for all Variants“ By deactivating this option for a distinct variant - after this variant been selected - and specifying a different grid appearance for this variant, this option is automatically deactivated by CadnaA for all other active variants. For these variants, however, the current grid appearance settings are not changed. In case this option is deactivated (for one or for all variants) and the grid appearance settings match for all active variants, the option is activated by CadnaA for all variants automatically. CadnaA - Reference Manual 5 38 5 Chapter 5 - Immissions 5.3.2 Grid Appearance 5 CadnaA - Reference Manual 5 39 Chapter 5 - Immissions 5.3.3 Grid Calculation 5.3.3 Grid Calculation The command Calc Grid in the Grid menu launches the grid calculation. With more than a single variant active, the following dialog is displayed enabling to select variants: 5 Dialog Calculation (via command Calc Grid on Grid menu) In this case, the grid of the active variant or the grids of all variants or a selection of variants can be calculated. With lasting grid calculations the following, estimated time intervals, estimated based on the calculation progress and the project size, are displayed on the progress dialog: • the elapsed time interval (format hh:mm:ss) and • remaining time interval for the calculation (format hh:mm:ss). If no calculation area has been defined (see chapter 6.4 "Selecting Data for the Calculation") the calculation is performed within the entire limits (see Options|Limits menu). Otherwise, only the active calculation areas will be calculated. CadnaA - Reference Manual Calculation Progress 40 5 Chapter 5 - Immissions 5.3.3 Grid Calculation The grid calculation takes into account all objects and sound sources, even if they lie outside the specified calculation area (see also Check Consistency chapter 5.1.1). 5 Update during Grid Calculation With the activated option „Update during Grid Calculation“ (menu Options|Miscellaneous) the calculated grid is built up by colored areas while the calculation is still in progress. Canceling/Interrupting the Grid Calculation A grid calculation may be stopped, or interrupted to be resumed later on, at exactly the point where it was stopped. Click the „Stop“ button and wait until CadnaA has interrupted the calculation. Resuming a Grid Calculation In order to later relaunch a canceled grid calculation, first save the project file. CadnaA will save with this the progress status of the grid calculation. Select the command Grid|Calculate Grid. while holding the SHIFT key depressed to resume the grid calculation. CadnaA - Reference Manual 5 41 Chapter 5 - Immissions 5.3.4 Grid Arithmetic 5.3.4 Grid Arithmetic The dialog Grid Arithmetics offers to generate new grids from several input grids, for example, in order to generate the sum or the difference of grids. 5 Dialog Options The current grid is assigned by R0 (or r0). By clicking on the file selector symbols up to 6 saved grids can be loaded (file formats *.cna or *.cnr). Use Grid In these boxes a formula can be entered for each evaluation parameter defined using the grids R0 and R1 to R6 respecting the rules for expressions and operators (see Chapter 5 - Operators & Functions in the manual „Attributes, Variables and Keywords). When clicking OK the new grid is calculated processing the numerical expression/s. Expression for new Grid Example: • • • grid R1 with obstacles and screening grid R2 without obstacles difference grid R2-R1 showing screening effect (Abar) as a grid map For further examples see the CadnaA-manual „Attributes, Variables, and Keywords“. CadnaA - Reference Manual 42 5 5 Chapter 5 - Immissions 5.3.4 Grid Arithmetic Input Boxes for Evaluation Parameters The check boxes in front of the four evaluation parameters enable to define specific expressions for each evaluation parameter. Per default, none of the check boxes is activated. This causes the expression for the first evaluation parameter (Ld/Day for evaluation parameter LP1, see chapter 6.2.5) to be applied to all other evaluation parameters as well. Activate the respective check box to enter a different expression for this evaluation parameter. New Grid is Intersection of Input Grids When several grids are loaded this option causes to just evaluate and display the grid area which is an intersection of the input grids (i.e. where the input grids are overlapping). This option is activated by default. Grids in Variants Provided the project file contains several variants these can be assigned as well - besides the current variant (for table with variables, see section "Grid Variables for Evaluation Parameters"). Examples Grid Summation Enter in the first input box „Expression for New Grid“ the formula r0+1. Since the check-boxes for the other evaluation parameters are deactivated, the calculation is applied all evaluation parameters in the same way. The same effect would occur when activating all check-boxes and entering into each input box, starting from the first one: r01+1, r02+1, r03+1 and r04+1. CadnaA - Reference Manual 5 43 Chapter 5 - Immissions 5.3.4 Grid Arithmetic In this example, the current grid (r0) and the loaded grids R_B.CNA and RK_G.CNA are added energetically. From this sum the loaded grid RK_STR.CNA are linearly subtracted. By using the settings below the calculation occurs for all evaluation parameters using the same expression. Energetic Summation 5 In this example, the grid is calculated and saved using a point source in front of a reflecting barrier. Afterwards this file is loaded to field R1. Now, deactivate the reflection (by setting the reflection order to zero on tab „Reflection“ in the configuration, see chapter 6.2.8) and restart the grid calculation. Calculate the difference by subtracting the current grid (r0) from the loaded grid R1 using the expression r1-r0. The resulting grid shows the level increase due to reflection. CadnaA - Reference Manual Difference Grid 44 5 Grid Variables for Evaluation Parameters Chapter 5 - Immissions 5.3.4 Grid Arithmetic In a grid or a grid file up to four evaluation parameters plus a ground grid can be saved. In case the designation for the variant Vyy is missing the current variant is evaluated. The distinct grids can be addressed as follows: R0 refers to the current grid with all defined evaluation parameters. A grid arithmetics would effect all grids of all evaluation parameters. R01 to R04 refers to the current grid, just for one the defined evaluation parameters 1 to 4 R0g refers to the current ground grid R1 refers to a saved grid loaded to input box R1 and effects the grids of all evaluation parameters R11 to R14 refers to the grid loaded to input box R1, just for one the defined evaluation parameters 1 to 4 R1g refers to the ground grid loaded to input box R1 R3 to R6 analogously as described above R1V01 refers the grid of all evaluation parameters in variant V01, loaded to input box R1 R1V011 to R1V014 refers the grid of one of the evaluation parameters 1 to 4 in variant V01, loaded to input box R1 R6V161 to R6V164 refers the grid of one of the evaluation parameters 1 to 4 in variant V16, loaded to input box R1 5 NOTE - The reference to a variant must use a doubledigit (RxVyyEvalParaNo or rxvyyEvalParaNo with x=1..4, yy=01..16, EvalParaNo=1..4). Combining Grids using different Calculation Areas When combining grids which are using different calculation areas, please note that CadnaA compresses all grids automatically upon calculation in order to save disk space. In these cases - especially when grid arithmetics is displaying odd results - it requires to decompress all grids prior to applying the grid arithmetics (see chapter 5.3 "Receiver Grid"). CadnaA - Reference Manual 5 45 Chapter 5 - Immissions 5.3.4 Grid Arithmetic When several grids are loaded this option causes to just evaluate and display the grid area which is an intersection of the input grids (i.e. where the input grids are overlapping). This option is activated by default. option „New Grid is Intersection of Input Grids“ 5 CadnaA - Reference Manual 46 5 Grid calculations for EU-noise indices with CRTN Chapter 5 - Immissions 5.3.4 Grid Arithmetic When applying the English guideline CRTN ("Calculation of Road Traffic Noise") in conjunction with calculations according to the EC Environmental Noise Directive /121/ the L10 grid can be converted to a Leq grid according to method 3 of the TRL-study (/83/) in order to evaluate Lden and Ln. The entire procedure requires several steps: 1. 5 setup for calculation of initial levels LA10,18h for Non-Motorways and Motorways: In order to calculate LA10,18h select the performance parameters Ld on the tab Performance Parameters (Calculation| Configuration menu) with CRTN selected as road standard. Later, the conversion of levels LA10,18h into levels Lden and Ln according to TRL-study can be performed with both, non-motorways and motorways, in a single CadnaA-file provided that non-motorways and motorways are addressed to two variants. 2. Define three variants, for non-motorways, motorways, and for all roads. Define groups according to IDs being different for non-motorways and motorways, for example: As the grid is calculated just for the active variant the grids for nonmotorways and motorways has to be calculated in two steps. 3. Select variant "non-motorways" and calculate grid. Save this grid via Grid menu, Save as (e.g. filename "non_motorways.cnr"). CadnaA - Reference Manual Chapter 5 - Immissions 5.3.4 Grid Arithmetic 4. 5 47 Switch to variant "motorways" and calculate grid. Next, the two grids for LA10,18h are converted into grids Lden and Ln. 5. Activate the END-performance parameters 1: Lden and 2: Ln on the dialog Configuration (Calculation menu). Make sure that hours are allocated to the three daily periods D, E, N and penalties are entered. 6. Convert grids using the following expressions via the dialog Grid Arithmetic (on Grid menu) for „Expression or a new Grid“ with the syntax: crtn_X (LA10,18h_nonmot, LA10,18h_mot) with the possible evaluation parameters X = (d, e, n, den) At the first location within the brackets, the L10 grid for "non-motorways" is referenced (e.g. LA10, 18 h_nonmot). At the second location, the L10 grid for "motorways" is referenced (e.g. LA10, 18 h_mot). With the specifications as in a following illustration the grids for Lden and for Ln result in a single step. In the example above, the present grid is for „motorways“ (R0) while the loaded grid R1 is the grid for „non-motorways“. The expressions to be entered are: for Lden:crtn_den(r11,r01) for Ln: crtn_n(r11,r01) CadnaA - Reference Manual 5 48 5 Chapter 5 - Immissions 5.3.4 Grid Arithmetic Please consider that the first grid has to be always the grid for nonmotorways and the second for motorways. 7. In this example, the result are grid for Lden (1st parameter) and Ln (2nd parameter). Select variant "all" to activate both types of roads. Explanatory Remarks: The TRL-study /83/ lists regression formulas to recalculate Leq for the time periods Day, Evening, and Night based on statistical evaluations. When just having daily traffic counts available „Method 3“ of the TRL-study applies. 5 For non-motorway roads: Lday 0.95 LA10,18 h 1.44 dB (Equation 1) Levening 0.97 LA10 ,18 h 2.87 dB (Equation 2) For motorway roads: Lnight 0.90 LA10 ,18 h 3.77 dB (Equation 3) Lday 0.98 LA10 ,18 h 0.09 dB (Equation 4) Levening 0.89 LA10 ,18 h 5.08 dB (Equation 5) Lnight 0.87 LA10 ,18 h 4.24 dB (Equation 6) The above equations will be used in CadnaA when converting the grid for LA10,18h into the resulting grids for Lden and Ln. Additional features for grid conversion with CRTN CadnaA offers additional commands for converting LA10,18h into Ld and Le. The general syntax is: crtn_x (LA10,18h_nonmot, LA10,18h_mot) where x = (d, e, n, den) LA10,18h_nonmot: grid for non-motorways LA10,18h_mot: grid for motorways This conversion respects the allocation of hours and the entered penalties. Example 1 The expression: crtn_den (r01, r11) converts the parameter 1 for non-motorways in the current grid (r01) and the parameter 1 for motorways of loaded grid r1 (r11) into Lden-grid. For evaluation the Lden-grid based on Leq-levels Ld, Le, and Ln the expression is: CadnaA - Reference Manual 5 49 Chapter 5 - Immissions 5.3.4 Grid Arithmetic Lden(day, evening, night) This conversion respects the allocation of hours and the entered penalties as well. Having three grid for Ld, Le, Ln calculated the Lden-grid can be generated as the 4th grid by entering the following expression: Example 2 Lden(r01, r02, r03) converts the parameter 1,2,3 of the current grid (r01, r02, r03) into Lden grid see also: chapter 11.2.1 "Editing the Result Table", section "Conversion to EUindices at individual receivers with CRTN / TRL" CadnaA - Reference Manual 5 50 5 Chapter 5 - Immissions 5.3.4 Grid Arithmetic 5 CadnaA - Reference Manual 5 51 Chapter 5 - Immissions 5.3.5 Generating a Grid from Noise Contours 5.3.5 Generating a Grid from Noise Contours A noise grid can be generated in CadnaA from Iso-dB-lines (noise contours) using an external file format. In some cases, there will be just Iso-dB-lines (e.g. aircraft noise contours) available in some external format. In order to add this information to the already existing grid it requires to generate a grid using those geometrical lines, representing noise contours (see chapter 5.3.4 "Grid Arithmetic"). 5 In a first step, the geometrical lines, representing noise contours, are exported to DXF format (with activated option „Height is Level“ and deactivated option „No Grid points“). Now, this exported DXF file is used to generate a grid from these isolines. To this end, import the DXF file into a new CadnaA file (thus, avoiding to recalculate the existing grids of evaluation parameters, if any). • Select from File|Import menu the format „AutoCAD DXF“. • In the Options dialog import the Iso-dB-lines as contour lines (with layer name *). Deactivate the auxiliary polygons at the end of the list. This procedure, however, just works in case the level values are stored as heights of the terrain contours in the import file. • Now, calculate ground grid (its calculated automatically with Grid|Calc Grid command). • Enter class width and an upper and lower limit and specify the grid‘s receiver spacing (menu Grid|Specification). • When calculating the ground grid, no source is required. Open from the Grid menu the dialog Arithmetics and enter this expression for new grid: r0g By this, the grid of ground heights has been converted to a noise grid which can be saved for further use. To do this select any evaluation parameter from the toolbar (but not „Ground“ grid) and select command Grid|Save. The saved grid file can be opened and used for further grid arithmetics (input boxes R1 to R6). CadnaA - Reference Manual Examples\07_Import\DXF\IsodB.dxf 52 5 Chapter 5 - Immissions 5.3.5 Generating a Grid from Noise Contours When the level information is just available as text (so, not as a numerical value stored, but e.g. in the ID of the terrain contours) there is a further possibility to extract the value form the string information. 5 Sound level values as text information in the ID, i.e. the values are not assigned as height Proceed as described in the following. Examples\05_Immissions\Raster_IsodB.cna • Change the string in the „ID“ column by applying the context menu command Change Column (see chapter 11.1.3) in a way that just the level value remains. Using the example above, the following input generated the desired result. CadnaA - Reference Manual 5 53 Chapter 5 - Immissions 5.3.5 Generating a Grid from Noise Contours 5 expression for Replace Strings remaining results are just the sound level values Now, the values in the ID column have to be transferred to the column „Height, Begin“. Therefore • Click with the right mouse key into the white area on the screen and select the context menu command Modify Object. • Select the action „Modify Attribute“ for the object type „Contour Line“ and confirm by OK. • On the dialog Modify Attribute select the attribute HA (for height at the first point) and the option „Arithmetic“, with „New Value“ = ID (you may select this attribute via the double-arrow key instead). CadnaA - Reference Manual Double-arrow key 54 5 Chapter 5 - Immissions 5.3.5 Generating a Grid from Noise Contours 5 Settings to insert the sound level value from the ID box into the height column • Close the dialog with OK and confirm the subsequent dialog with „All“. Subsequently, the level values from the ID column are inserted into the height column. Now, proceed as described at the begin of this chapter to calculate the ground grid. In this example a grid spacing of 5 x 5 m has been used. CadnaA - Reference Manual Chapter 5 - Immissions 5.3.5 Generating a Grid from Noise Contours 5 55 5 Iso-dB lines imported as terrain contour lines grid generated by using imported terrain contours (appearance: areas of equal sound level) CadnaA - Reference Manual 56 5 Chapter 5 - Immissions 5.3.5 Generating a Grid from Noise Contours 5 CadnaA - Reference Manual 5 57 Chapter 5 - Immissions 5.3.6 Vertical Grid 5.3.6 Vertical Grid By the object Vertical Grid grid calculations can be performed on vertical sections resulting in a colored vertical noise map. Vertical grids may be printed, copied or saved and reopened. Furthermore, vertical grids are displayed on the 3D-special view. The following example shows a road and two buildings. Example 5 Select the object Vertical Grid from the toolbox and draw a polygon with two points determining the location of the vertical grid. An arbitrary number of vertical grids can be entered. The default height for the vertical grid is 20 m. This height can be modified on the dialog Geometry. Up to this height the grid calculation is performed. Vertical noise map up to 50 m height in the 3D-Special View CadnaA - Reference Manual 58 5 Dialog Options Chapter 5 - Immissions 5.3.6 Vertical Grid When opening the dialog Vertical Grid the graphics uses the same scale as at the horizontal grid. By default, also the grid specification (see chapter 5.3.1) and grid appearance settings (see chapter 5.3.2) of the horizontal grid are applied. 5 Dialog Vertical Grid Option „Global“ With this option activated (default) the settings of the horizontal grid are used. After deactivation of this option, individual settings of the grid can be edited using buttons „Specification“ and „Appearance“. Button „Calculate“, option „automatically Clicking the button „Calculate“ starts the calculation of the vertical grid. During this calculation the dialog remains open. When the option „automatic“ is activated, the vertical grid will be recalculated each time the horizontal grid is calculated. This requires to close the dialog first. Button „Save as“ This button offers to save the vertical grid (file extension *.cnr). Loading Vertical Grids Saved vertical grids can be opened using the key combination ALT+o (letter „o“) CadnaA - Reference Manual 5 59 Chapter 5 - Immissions 5.3.6 Vertical Grid After calculation the sound level at the location of the mouse pointer is displayed in the upper part of the dialog (to the right of „Grid“). Display of Level Via this button the graphics is copied to the clipboard and can be inserted into another application using the key combination CTRL+v. Button „Copy“ With several active vertical grids in a file, the grids are displayed all together on the 3D-View (see chapter 9.13) and in the 3D-Special View (see chapter 9.14). 3D-Special View Via the Properties menu of the 3D-Special view a transparency (%) to the vertical grid can be defined. This enables to display objects covered by the vertical grid. Grid transparency Vertical grids can be referred to in PlotDesigner. This holds for the 3DSpecial view and laos for sections as shown on dialog Vertical Grid (see chapter 13.1.3, section "„Plan“ tab"). PlotDesigner The generation of level difference grids is possible also with vertical grids. Proceed as follows: Grid Arithmetics • Save the two grids to be subtracted from each other using the button „Save as“ on the dialog Vertical Grid. • Now, load one of the two vertical grids using the command Open on menu Grid. A current grid r0 is required for the calculation. The resulting grid is placed at the origin (x, y)=(0,0) in the xy plane. If necessary, expand the limits to check for the resulting grid (menu Options|Limits). CadnaA - Reference Manual 5 60 5 5 Chapter 5 - Immissions 5.3.6 Vertical Grid • Open the dialog Grid Arithmetics from the Grid menu and load the two vertical grids, e.g. for R1 and R2. • Generate the difference grid, e.g. using the formula R2-R1, and save the resulting grid using a new filename. • Open the dialog Vertical Grid of the referring object and press the key combination ALT+o (letter „o“). After loading the file the level difference grid is displayed (check for the level displayed when moving the mouse within the grid’s area). • Alter - as required - the options on dialog Appearance with respect to the level range of the difference grid. Dialog Vertical Grid displaying a difference grid, using the color palette „pal_0_20_step_2“ with areas of equal sound level see also: chapter 12.6.1 "Default Color Palettes" CadnaA - Reference Manual 5 61 Chapter 5 - Immissions 5.4 Building Evaluation 5.4 Building Evaluation According to the requirements of RLS-90 /17/ and using the map symbols defined in this guideline, there is a fairly simple way of demonstrating for a building close to a traffic route whether the predefined and maximum permissible rate levels on the basis of designated land use have been exceeded. It is also possible to ascertain which storeys this is true for and which values are to be expected at the most exposed position of the facade during the day and night. • We activate - for better understanding and not because it is necessary - the option „No calculation of Building Noise Map“ in the menu Options|Building Noise Map (see chapter 5.4.1). • Insert the object „Building Evaluation“ with the corresponding icon from the toolbox. For that, click inside the building plan for that building for which an evaluation is supposed to be made. • After placing the first symbol we should adjust the size if necessary. All further inserted symbols then have the same size. 5 Procedure Examples\05_Immissions\Industry.cna If several or even all buildings or only buildings with a certain condition of a project shall be evaluated we can use the command from the context menu Modify Object, action „Generate Building Evaluation“ to insert the Building Evaluation symbols all at once (see manual "Introduction to CadnaA"). In this case CadnaA automatically places these symbols in the selected buildings. The name of the building, entered in the identically named edit box in the edit dialog, will be automatically transferred into the corresponding input box of the building evaluation symbol. In order to generate a building evaluation only for buildings e.g. with a certain height and/or base area a corresponding numerical condition can be defined. CadnaA - Reference Manual Building Evaluation with Condition 62 5 Chapter 5 - Immissions 5.4 Building Evaluation 5 Action „Generate Building Evaluation“ with condition To insert an expression for a condition activate the pertinent check box and either enter an attribute (see CadnaA-manual „Attributes, Variables, and Keywords“) via keyboard or select them from the list which opens by clicking the button with the double-arrows. With the above example would be generated symbols for all buildings which have a relative height higher than 3 m and a base area bigger than 50 m². In this case both conditions must be „true“. Symbol Size Adjust the symbol sizes via the table Building Evaluation (Tables menu|Other Objects) using the context menu command Change Column (see chapter 11.1.3), and also define the type of Land Use (if any). First insert just one symbol and specify all settings as required. CadnaA will keep the settings for all further building evaluation symbols when using the action „Generate Building Evaluation“. CadnaA - Reference Manual Chapter 5 - Immissions 5.4 Building Evaluation 5 63 5 Default situation: The building evaluation symbol is set for the upper left building. The calculation has not been launched yet When a building is evaluated, levels computed by CadnaA for all storeys and in front of all facades are compared to the pertinent limit values or standard values. The latter can be defined in two ways. • Double-clicking on the building evaluation icon opens the corresponding dialog. • Activate the appropriate option for the standard values. If the option „Determine from Designated Land Use“ is deactivated, you can select the type of area by clicking the card-index icon next to the „Land Use“ box, and the type of noise can be selected in the „Use Standard Values for“ list box. Although this building evaluation was originally aimed at traffic noise, this flexible concept can also be applied to other types of noise like, e.g., industrial noise. CadnaA - Reference Manual 64 5 Chapter 5 - Immissions 5.4 Building Evaluation 5 Building Evaluation of a building in a residential area (WA), with respect to road traffic noise Designated Land Use icon The second way is to click the Designated Land Use icon and assign a type of land use to an area by drawing a closed line around it. Then activate the option „Determine from Designated Land Use“. The standard values to be compared should then be known. When all buildings have been provided with a building evaluation symbol, and the calculation is triggered by clicking the Pocket-Calculator icon on the toolbar, the progress bar window will first display the calculation for the specified receiver points and then the progress of the building evaluation. In this building evaluation, calculations are performed and evaluated one after the other • for all buildings bearing this symbol, • for all storeys which result from the ratio of building height to storey height (storey heights may be edited under button „Options“ on the edit dialog Building Evaluation), and • for all outer facades. CadnaA - Reference Manual Chapter 5 - Immissions 5.4 Building Evaluation 5 65 5 Building Evaluation Symbol after calculation Upon completion of the calculation, the top semicircle of the icon indicates the range of storeys where excess levels occur. If it remains blank, no excess levels occurred, or no area of designated land use has been assigned. The bottom quarters display the levels according to the selected „Averaging Method“ for the first and second evaluation parameter (see chapter 6.2.5). By default, these are the daytime level Ld and the night-time level Ln. I-VII 7060 I-II 6858 I-III 6757 I-II 6959 I-III 6858 I-II 6959 I-II 7161 I-II 7161 I-II 7261 I-II 6252 Labeling of the buildings after calculation CadnaA - Reference Manual I-II 6959 66 5 Use different Calculation Point 5 Chapter 5 - Immissions 5.4 Building Evaluation In some cases it could make sense to place the building evaluation symbol outside the layout of the house. For that you can check the option „Use different Calculation Point“ on the dialog Geometry and place the symbol somewhere outside of the house without loosing the connection to this building. The original coordinates will be saved. • Insert the symbol within the building base. • Open the dialog Geometry and check the pertinent option. • Close all dialogs with OK and push the symbol outside the building. The calculation point is displayed with a connecting line (auxiliary polygon). Attribute: USE_PCALC Activation via Change Attribute|string: „x“ When transforming the Building Evaluation Symbol (via dialog Modify Objects or via the context menu, action/command Transformation) the connecting line will be transformed automatically. Excluding Facades In the edit dialog Building Evaluation if you click on the button „Option|Exclude Facade“ another dialog opens in which you can mark facades not to be taken into account for a calculation. For the calculation options „Facade points acc. to VBEB“ and „Facade points acc. to CNOSSOS“ (see chapter 5.4.1), the exclusion of façades is not possible for the time being. CadnaA - Reference Manual Chapter 5 - Immissions 5.4 Building Evaluation 5 67 5 Dialog Exclude Facades In order to exclude a facade, click once on the identifier in the upper table (e.g. F01) or double-click on a facade in the graphics below. Marked facades are excluded from the next calculation. On the lower graphic, the excluded facade is marked by a thick black line and the black dot (facade point) gets deleted. By clicking again on the identifier of a facade or doubleclicking in the graphics this will again be included in the calculation. The exclusion of non-relevant facades can save a reasonable amount of calculation time when evaluating a building noise map. At maximum 256 facades can be excluded. CadnaA - Reference Manual 68 5 Importing Building Evaluation Symbols 5 Chapter 5 - Immissions 5.4 Building Evaluation In case the buildings and the accompanying building evaluations are saved in separate files after a calculation run, no proper link between both objects is established when re-importing the building evaluations into the file with the buildings (via menu File|Import). This causes all building-related evaluations to fail (e.g. via the ObjectScan, Grid menu - requires option XL), since the corresponding data for the buildings does not exist (e.g. the building noise levels HB_LP1 to HB_LP4). In those situations, the link between the buildings and the building evaluations has to be reestablished. Use the command Link Buildings to Building Evaluations on the Extras menu to update the link. Please consider that when loading the building evaluations via the command PCSP|Load PCSP-Tiles (Calculation menu) the link is updated automatically (see chapter 6.10 "PCSP - Program Controlled Segmented Processing"). The above statements just hold when importing the calculated building evaluations via the menu File|Import. CadnaA - Reference Manual 5 69 Chapter 5 - Immissions 5.4.1 Building Noise Map 5.4.1 Building Noise Map Using the object „Building Evaluation“ (see chapter 5.4) enables to display the maximum sound level across the storeys of a building where an exceedance of a limiting value occurs. Furthermore, a colored building noise map based on the level calculated for each storey is produced. In conjunction with the use of variants (see chapter 14.2) to calculate different scenarios, also level difference maps at building facades can be generated (see chapter 5.4.3) and displayed. • Insert the object „Building Evaluation“ with a mouse click on the building plan. • In edit mode, double-click on the border of the building evaluation symbol and define a standard value by selecting the pertinent option. CadnaA - Reference Manual 5 Procedure 70 5 Chapter 5 - Immissions 5.4.1 Building Noise Map The options for the data displayed on the building noise map are available on the menu Options|Building Noise Map. 5 • If necessary deactivate the option „No Calculation of Building Noise Map“ and set the further desired parameters by input or selection. • Start the calculation with the pocket calculator from the toolbar or with menu command Calculation|Calc. Dialog Building Noise Map/ Building Evaluation Dialog Building Noise Map/Building Evaluation (on Options menu) CadnaA - Reference Manual 5 71 Chapter 5 - Immissions 5.4.1 Building Noise Map DIALOG OPTIONS Calculation Selecting the method used to generate facade sections: • Facade points via facade lengths: The distribution of the facade points along the facades of the buildings is based on the minimum and maximum facade length. • Facade points according to VBEB: The distribution of the facade points follows the regulation in VBEB /113/. The minimum facade length is therefore 2.5 m, the maximum 5 m. • Facades according to CNOSSOS: The distribution of the facade points follows the regulation for CASE 1 from CNOSSOS-EU /16/. Select the option „Facade points via facade length“ to apply CASE 2 from CNOSSOS-EU and enter 5 m for „maximum facade length“. Facade points via/acc. to ... 5 CadnaA subdivides the facade based on the entered length and inserts a level symbol into each section. minimum/maximum Length of Facade This value specifies at which distance the facade points are generated off the buildings facade surface. In conjunction with the configuration setting for „Minimum Distance Receiver - Reflector“ (see chapter 6.2.8 "Reflection Tab") this will define whether the facade levels consider the reflection at the building’s facade or not. Distance ReceiverFacade (m) The default value is 0.05 m. The default setting for „Minimum Distance Receiver - Reflector“ of 1 m means that, the reflection at the building’s facade is not considered in the facade levels. CadnaA - Reference Manual 72 5 Chapter 5 - Immissions 5.4.1 Building Noise Map Additional Free Space Is the distance from the facade point to the next obstacle smaller or equal to the value entered, no façade point/s will be generated and calculated. This may be useful when buildings have been imported having small gaps between each other, but should calculated as without gaps. The default value is 0 m. Averaging Method This selects the method for the calculation of the characteristic noise level of each building from the noise level of the facades (arithmetic, energetic average value, minimum or maximum value). The resulting value is shown inside the building evaluation symbol for the first two evaluation parameters (see chapter 6.2.5 "Evaluation Parameters Tab"). No Creation of Building Noise Map By activating this option, no noise map is calculated and displayed for the buildings. The building evaluation, however, is still executed as long as the symbol/s are activated. 5 Appearance of Building Noise Map Show Facade Points Select from the list box the facade points/levels to be displayed on the building noise map. The floor numbering as selected on the dialog Miscellaneous is used (see chapter 9.15). The storey’s designation can be displayed on the Result Table using the string variable STW (see chapter 2.1 in the CadnaA manual „Attributes, Variables, and Keywords“). Symbol Type Either „Octagon“ or „Ribbon“ can be selected. Size of Exceeding/Not Exceeding Symbol The size of the facade point symbols exceeding or not exceeding the limiting value may differ. Selecting the unit (m) will adjust the size of the symbol when change the scale, but not when selecting the unit (mm). Color Symbols according to Level Activating this option will colorize the facade point symbols according to the color palette specified via the menu Grid|Appearance. CadnaA - Reference Manual 5 73 Chapter 5 - Immissions 5.4.1 Building Noise Map When this option is activated (default setting) the facade level displayed for each face point will apply the rounding rule as specified in the respective building evaluation symbol. Otherwise, the level not being rounded off will be displayed (integer value). In conjunction with the color palettes (see chapter 5.3.2 "Grid Appearance" and chapter 12.6 "Color Palettes") and the option „Size of Exceeding/Not Exceeding Symbol“ this option can be used to define a rule for the color and the size of the facade point symbols applying the rounding or not. option „Use rounded values“ activated (file BuildNoiseMap - Option Use rounded values ON.cna): option „Use rounded values“ deactivated (file BuildNoiseMap - Option Use rounded values OFF.cna): The level at the lower left facade point is larger than 64.0 dB(A), but smaller than 64.1 dB(A). So, the limiting value of 64 dB(A) is respected considering the rounding rule 0.1 dB. The rounding rule is not considered when displaying the facade point levels. So, all levels larger than 64 dB(A) will be exceedances and displayed as such. *) Use rounded values 5 *) This setting corresponds with former releases of CadnaA (prior to release 4.1). Open the file BuildNoiseMap-Option Use rounded values ON.cna in directory Examples\05_Immissions. The limiting value in this example is 64 dB(A) and the rounding used is 0.1 dB. Thus, applying this rule to 64.1 dB(A), for example, will cause a rounded value of 65 dB(A). Values form 64.0 to 64.1, however, will be rounded off to 64 dB(A) and respect the limiting value, consequently. Displaying the Result Table it can be checked at which facade points on the ground floor the level ranges between 64.0 and 64.1 dB(A). CadnaA - Reference Manual Examples\ 05_Immissions 74 5 Chapter 5 - Immissions 5.4.1 Building Noise Map In the next figure, the nominal level exceedances are indicated by a red color and an enlarged size of the facade point symbol. Print in Symbols Activation of this option will show either the level - in addition to coloring within the level symbol. Alternatively, the number of the facade point number generated by CadnaA is displayed. The facade levels can be displayed in the Result Table (see chapter 11.2) by selecting from the list box „Receivers from Building Noise Map“. The facade point numbers can be displayed in the Result Table by use of the string variable FASSNR. Apply By clicking the „Apply“ button, the actual the settings are applied instantaneously, without closing the dialog. When changing now the facade length the effect is just visible after a new calculation. By clicking the „Cancel“ button the altered settings will be ignored. 3D-Special View The building’s facades are also displayed in colors on the 3D-special view according to the specified grid caption after a calculation. Dialog Options Arithmetic With the „Arithmetic“ field you are able to calculate different formula for or with the noise map of buildings, e.g. level-difference-map for building noise (see chapter 5.4.3) 5 In case a horizontal receiver grid has already been calculated you can allocate interpolated grid values to facade points. A separate calculation of a noise map for buildings is unnecessary which would save calculation time. Independent from the number of defined evaluation parameters (see chapter 6.2.5) the calculation results of the horizontal receiver grid provides a basis for the building evaluation. Prior to the allocation is that building evaluation symbols have to be addressed to the relevant buildings and the facade points been generated which can be generated by a „dummy“ calculation with a point source. CadnaA - Reference Manual 5 75 Chapter 5 - Immissions 5.4.1 Building Noise Map 1. calculate the receiver grid 2. generate face points with calculation of one single noise source (e.g. point source - all other noise sources deactivated with Modify Objects, action „Activation“, „Deactivate“ for all objects except the buildings and the building evaluation symbols 3. calculate the dummy noise map of buildings with the calculator symbol on the toolbar 4. On dialog Building Noise Map, dialog range „Arithmetic“ enter the expression r0 and click the button „Perform Calculation“. By the expression r0 the interpolated calculation results of the horizontal grid will be allocated to the corresponding evaluation parameters of the facade points, not depending in what evaluation parameter’s input box (in this example Day|Night) the expression was entered. Subsequently, when selecting one of the evaluation parameters from the list on the toolbar, the respective results are displayed within the facade points. CadnaA - Reference Manual Example 5 76 5 Chapter 5 - Immissions 5.4.1 Building Noise Map To address interpolated results of the horizontal receiver grid, coordinates or the ground height to the facade points, the following additional expressions can be used in a formula: 5 Example Input Result r0 allocation of the results from the horizontal grid to all the corresponding evaluation parameters r01 to r04 allocation to the corresponding evaluation parameter LP1 - LP4 (r01 allocates the result to LP1, r02 to LP2 etc. - special application) x|y|z evaluates the corresponding x-, y- or z-coordinate of the facade point (z allocate the z-coordinate to the facade point - special application) g evaluates the ground height at the facade iif(STW==1, r0, LP1) (in words: if it is the first floor then address the interpolated result from the grid - otherwise not, i.e. keep the existing value) CadnaA - Reference Manual 5 77 Chapter 5 - Immissions 5.4.1 Building Noise Map Using the CadnaA option X or XL (see Chapter 15 - Options X & XL) also facade points are selectable as object type for evaluation. Option XL For the facade points the following attributes are available: Attribute Explanation TOT_EINW total no. of inhabitants of a building to which the corresponding facade point belongs to FAC_EINW number of inhabitants assigned to a facade point, with the same number of inhabitants is assumed per facade length FAC_EINW_xy number of inhabitants assigned to a facade point, weighted by applying the following options: - for x: L inhabitants weighted using the length of each facade section C inhabitants per facade section - for y: A for all facade points (includes also the deactivated ones, if any) (blank) just the „active“ facade points are considered STW floor identifier (ground floor=0, 1st floor=1, 2nd floor=2 etc.) FAC_NR number of facade points counted from the first point of the building (FAC_NR=1, FAC_NR=2 etc.) to the last facade point FAC_LEN corresponding facade 2D-length (m) of the facade point TOT_LEN sum of all facade lengths referring to the facade points TOT_LEN_N sum of all facade lengths referring to the facade points, facade lengths deactivated by the option „Additional Free Space“ are not considered FAC_AREA corresponding facade area (m²) of the facade point TOT_AREA sum of all facade areas referring to the facade points TOT_AREA_N sum of all facade areas referring to the facade points, facade areas deactivated by the option „Additional Free Space“ are not considered TOT_FAC number of facade sections TOT_FACPTS number of facade points TOT_FACP_N number of facade points, facade points deactivated by the option „Additional Free Space“ are not considered CadnaA - Reference Manual 5 78 5 5 Example Chapter 5 - Immissions 5.4.1 Building Noise Map CENTER_X x-coordinate of the buildings center point CENTER_Y y-coordinate of the buildings center point CENTER_ANG angle between the buildings center point and a facade point, North direction = Zero BLDG_AREA building‘s ground area, for facade points BLDG_ID building ID (for facade points) - for internal use only LPFLMAX1 .. 4 maximum level per storey for evaluation parameters 1 to 4 LPCNOSS1 .. 4 level according to CNOSSOS-EU per storey for evaluation parameters 1 to 4 (see chapter 15.1, section „CNOSSOS“ in the CadnaA Reference Manual for details) If, e.g. the assigned number of inhabitants to a facade point should be evaluated select „Facade Point“ as object type and enter the following attributes and expressions in the input boxes: for „Formula for Summation“: FAC_EINW for „Formula for Total“: sum/num for more information see chapter 15.1 "Object-Scan" CadnaA - Reference Manual Chapter 5 - Immissions 5.4.2 Result Table for the Building Noise 5.4.2 5 79 Result Table for the Building Noise With the generator of the new result table you can define a table showing the results in a desired form. Immission Point Land Name ID Storey IP 01 IP 02 IP 03 Building 01 Building 01 Building 01 Building 02 Building 03 Building 05 Building 06 Building 07 Building 08 Building 08 Building 13 Building 19 Building 19 EG EG EG EG EG 1.OG EG EG EG EG EG 1.OG 1.OG MI MI MI MI MI MI MI MI MI MI MI MI MI MI MI MI Limiting Value Day Night dB(A) dB(A) 64 54 64 54 64 54 64 54 64 54 64 54 64 54 64 54 64 54 64 54 64 54 64 54 64 54 64 54 64 54 64 54 rel. Axis Station Distance Height m m m 22 21.51 0.50 0 53.58 1.50 51 35.94 1.50 123 9.19 2.50 126 8.80 2.50 133 12.08 2.50 107 9.70 2.50 91 8.83 2.50 61 12.24 5.30 43 11.82 2.50 26 11.71 2.50 165 9.57 2.50 162 9.67 2.50 81 8.59 2.50 141 12.78 5.30 138 12.81 5.30 Lr w/ Noise Control dL req. Day Night Day Night dB(A) dB(A) dB(A) dB(A) 59.6 49.3 53.2 43.0 51.2 41.0 68.3 58.1 4.3 4.1 68.7 58.5 4.7 4.5 65.1 54.9 1.1 0.9 68.1 57.9 4.1 3.9 68.6 58.4 4.6 4.4 66.7 56.5 2.7 2.5 66.9 56.7 2.9 2.7 66.8 56.6 2.8 2.6 64.5 54.2 0.5 0.2 64.5 54.2 0.5 0.2 65.7 55.4 1.7 1.4 66.4 56.2 2.4 2.2 66.4 56.2 2.4 2.2 Result table with receiver points taken from the noise map for buildings If you want to look at the results for the receiver points taken from the noise map of the building in addition to the standard receiver points, please activate the option „Receivers from Building Noise Map“ on the dialog Edit Result Table and choose the desired levels/storeys from the list box. CadnaA - Reference Manual 5 80 5 Chapter 5 - Immissions 5.4.2 Result Table for the Building Noise 5 Dialog Edit Result Table To show also the column Storey, insert a new line in the edit box’s result table if necessary. A double-click on the line will open the edit box’s table column. CadnaA - Reference Manual 5 81 Chapter 5 - Immissions 5.4.2 Result Table for the Building Noise 5 Column-Edit dialog of the Result Table Enter the parameters shown above and close the dialog box by clicking OK. The string variable STW represents the corresponding storey. The string variable STW displays the pertinent storey identifier. CadnaA - Reference Manual Storeys, string variable STW 82 5 String variable for Building Noise Map 5 Chapter 5 - Immissions 5.4.2 Result Table for the Building Noise Following string variables can be used in the Result Table to view more information about the facade points of a Building Noise Map: STW floor identifier: EG = ground floor 1.OG = first floor 2.OG = 2nd floor etc. FASSNR facade point number of the building noise map, starting with the first polygon point of the building. Example: On the basis of the facade partitioning (menu Options|Building Noise Map) 12 level icons are generated together for all sides of the building. Consequently, they will be covered intern with the facade numbering from 1, 2, 3 etc. till 12. If each level icon has even 5 storeys so each storey will be assigned to the corresponding facade number. DIR degree No. 0-360 where 0 is the North direction HIRI direction with one letter (N-North, O-East, S-South, W-West) HIRI2 direction with two letters if necessary (e.g. NW-North-West, SO-South-East) CadnaA - Reference Manual 5 83 Chapter 5 - Immissions 5.4.3 Level Difference Map for Building Noise 5.4.3 Level Difference Map for Building Noise With the so-called Building Noise Map in conjunction with using variants the differences in facade levels at buildings can be calculated easily. First, we calculate the building noise maps for all variants with Calculation|Calc, option „All Variants“. If we toggle variants by selecting the variant name at the toolbar the respective result is displayed on the screen. 5 To better recognize the levels, displayed in the symbols, deactivate the option „Color Symbols according to Level“, if necessary, or choose a different color palette with Open Palette in the menu Grid|Appearence| Option (see chapter 5.3.2). We calculate the level differences by subtracting the results of the variants. For that, open the dialog Options|Building Noise Map and enter a formula in the dialog range „Arithmetic, assign active Variant“. Calculate Level Differences Example We calculate the first variant V01 with the actual situation and the second variant V02 with the actual situation plus noise protection measures, e.g. a noise protection wall. What level differences does the noise protection wall gain at the facades? After calculating all variants (Calculation|Calc, option „All Variants“), we create another variant, e.g. V03 - differences - and activate this variant by selecting its name from the list box in the toolbar. In the dialog Options|Building Noise Map, option „Arithmetic, assign active Variant“ enter the following: LP1V01 - LP1V02 CadnaA - Reference Manual Examples\05_Immissions\Building Noise Map - Variants.cna 84 5 Chapter 5 - Immissions 5.4.3 Level Difference Map for Building Noise Click the button Perform Calculation. With this expression all evaluation parameters will be calculated if no other arithmetic field of has been checked. 5 If you want to calculate only a specific evaluation parameter you have to indicate the number of the desired evaluation parameter (LP1..4). The expression in the above dialog means evaluation parameter 1 (LP1) of the variant 1 (V01) minus evaluation parameter 1of the variant 2 (V02). The row names of the arithmetic fields (in this example „Day“ and „Night“) are changing depending on the name defined in the Calculation| Configuration, „Evaluation Parameter“ tab. The button „Apply“ displays the result immediately without closing the dialog. Otherwise close the dialog by clicking the OK button. CadnaA - Reference Manual Chapter 5 - Immissions 5.4.3 Level Difference Map for Building Noise 5 85 In this example the variant V03 will be overwritten if we calculate all variants again. The calculation of the level differences must be refreshed. The map of level differences for buildings is always displayed in the activated variant and therefore overwrites the existing result. The functions, which you can use in the Arithmetic box, are identical with those from the Result Table. For function and operators see CadnaA-manual "Attributes, Variables, and Keywords". CadnaA - Reference Manual 5 86 5 Chapter 5 - Immissions 5.4.3 Level Difference Map for Building Noise 5 CadnaA - Reference Manual Chapter 6 - Calculation 61 Chapter 6 - Calculation CadnaA enables • the calculation of sound propagation according to standardized procedures and • with settings that are defined by the user. This chapter deals with the second task and its possibilities with CadnaA and is therefore more concerned with the physical aspects of sound propagation. This is very important because CadnaA is used for expert work, in scientific work at universities and in lectures. Although the professional usage requires a strict application of the procedures fixed by standards and guidelines, it can be very useful the be able to process special calculation tasks which are not covered by the regulations in detail. Especially, this concerns the handling of reflections with higher order. According to the standard procedures a reflection of the first order is only dealt with according to the mirror image method, So just a single reflection of a ray at a flat surface. In case more orders of reflections contribute to the total result (e.g. at the building facades on both sides of a road), this will be taken into account - in the majority of road and railway noise standards - by calculating analytically a correction for multiple reflections from the geometrical and acoustic parameters. This strategy fails if the geometry of the building lateral to the road is completely different and varies from building to building. The same problem exists with the noise level in backyard locations. Those cases can just be treated by calculating higher orders of reflection. CadnaA - Reference Manual 6 2 6 Chapter 6 - Calculation 6 CadnaA - Reference Manual Chapter 6 - Calculation 6.1 Sound Rays and Reflection 6.1 63 Sound Rays and Reflection CadnaA is able to calculate reflections completely up to higher order. It is clear that this increases calculation times, because the number of rays grow exponentially with this reflection order. With the possibility to show all these calculated rays at the screen, CadnaA is a very helpful tool when teaching about sound propagation. The chapter chapter 6.1.1 "Sound Rays at Point Sources", chapter 6.1.2 "Sound Rays at Line and Area Sources" and chapter 6.1.4 "Reflection" treat the contents of a major publication, see reference /102/. It explains the way of segmentation of extended sources, like line and area sources and the projection technique applied with this. Furthermore, the calculation of multiple orders of reflections is explained, again applying the projection technique. It is worth mentioning that there are still some software packages available that do not apply any projection technique when segmenting area sources to assess the direct path. The partial levels of reflections evaluated with extended sources - like roads or parking lots - are arbitrary in this case and not conform to the specification found in the respective standards or guidelines. Chapter 6.1.7 explains how paths of rays can be displayed. Because of the selective display possibilities for the different orders (by using groups), the handling might look a bit complicated, but it is an excellent tool for clarifying the executed calculation and therefore can be helpful in a technical report in many cases. We recommend that the detailed examples be understood step by step. Once you have taken this initial hurdle the inclusion of ray representations in drawings and text documents is easily possible. CadnaA - Reference Manual 6 4 6 Chapter 6 - Calculation 6.1 Sound Rays and Reflection 6 CadnaA - Reference Manual Chapter 6 - Calculation 6.1.1 Sound Rays at Point Sources 6.1.1 65 Sound Rays at Point Sources In a physical sense a wave field goes out from a source Q which transports the sound power in all directions via the movement of the air particles. Because the surface of the spheres’ hull expands with increasing distance, and the sound power is distributed over the hull over a certain period of time, the sound intensity decreases and therefore the sound pressure level, too. With increasing distance source - receiver it becomes quieter. 6 Sound propagation from Source Q to Receiver Point RP physical (left) and numerical (right) If CadnaA calculates, the distance between source Q and receiver RP will be determined and, with the sound power level of the source, the sound pressure level at the receiver point will be calculated with analytical formulas which have been derived from the physical model. The wave field is in a certain way replaced by one ray from source to receiver. CadnaA - Reference Manual 6 6 Chapter 6 - Calculation 6.1.1 Sound Rays at Point Sources If there are many sources there are also many sound rays which have to be considered in the calculation. For all receivers affecting sound rays the calculated proportion of the level will be added energetically. IP1 IP1 Q6 Q6 Q1 Q1 IP2 Q2 IP2 Q2 6 Q3 Q3 Q4 Q5 Q4 Q5 IP3 5 Sources and 3 Receiver (IP) IP3 The Sound Rays CadnaA - Reference Manual 67 Chapter 6 - Calculation 6.1.2 Sound Rays at Line and Area Sources 6.1.2 Sound Rays at Line and Area Sources Even in the case of calculating the noise level from an extended source as the area source shown in fig. A, a distance has to be found that can be used in the equation of propagation. This may be wrong if the pivot of the extended source is used as starting point of the ray. Since, actually, each arbitrary portion of the area source emits sound, the same value of a level must result if the total stripe according to figure B is to be subdivided and the sound pressure level at the receiver point is calculated as the sum of the levels of the 5 contributions from the partial sources FQ1 till FQ5. 6 IP FQ A: Area source with sound ray IP FQ1 FQ2 FQ3 FQ4 B: Partitioning of the area sources However, the partial sources, according to figure B, result in different partial levels because of the different distances. On the basis of the energetic addition a higher sound pressure level results from fig. B than from taking into account only one ray emitted from the pivot as shown in fig. A. This error has been avoided in CadnaA by partitioning each extended line or area source in sufficiently small parts for automatic calculation. But these partial areas do not have the same size as shown in figure B. They become even smaller the closer the corresponding section of the extended source is to the receiver. This dynamic division, which must newly be calculated for each receiver, leads to a considerably faster calculation in comparison to the equal division. The following figure shows the sound rays, which CadnaA takes into account, with the irregularly shaped area source provided below. CadnaA - Reference Manual FQ5 8 6 Chapter 6 - Calculation 6.1.2 Sound Rays at Line and Area Sources IP 6 The sound rays of an area source considered by CadnaA. The same applies to line sources. By the road shown in the following figure the borders of the stripe are the axis of the outer lanes which are each considered as line sources and taken into account in the calculation of level . IP The sound rays of a roads considered by CadnaA. CadnaA - Reference Manual Chapter 6 - Calculation 6.1.3 Projection at extended Sound Sources 6.1.3 69 Projection at extended Sound Sources The automatic division of an extended sound source into smaller partial areas depending on the distance of the receiver (see chapter 6.1.2 "Sound Rays at Line and Area Sources") is not sufficient to avoid errors in the calculation of sound pressure levels. 6 IP Calculation of the area source „soccer field“ with two sound rays Let us take the example of a soccer field as in the upper figure. For a noise calculation at the remote receiver point IP CadnaA would split the soccer field into two partial areas and would therefore take into account two sound rays. This is correct for the shown situation. Now a shielding club house with a height of 8 m is located in the position shown in the following figure. IP Clubhaus Soccer field with partially shielding club house CadnaA - Reference Manual 10 6 Chapter 6 - Calculation 6.1.3 Projection at extended Sound Sources In the calculation of both displayed sound rays, screening and therefore a lower sound pressure level occurs in each case. But, in fact, not all partial areas, which are included in the calculation with the paths of the two rays, are shielded by the building. The resulting sound pressure level would be too low in the present example. CadnaA avoids this error by using a projection method. 6 With that, in the first step the area sources will be divided into shielded and non-shielded areas and in the second step subdivided according to the relation of area size to receiver distance. In this way, in the present example, 12 partial areas are created: altogether, nevertheless, because of the large distance from the receiver (340 m), 8 areas are not shielded and 4 areas are shielded. IP Clubhaus Two step division according to shielding objects in the path of rays and the distance of the receiver In the present example the calculation results in 44 dB(A) of free sound propagation, 39 dB(A) in the calculation of the situation with the club house without using the projection method and 42 dB(A) with correct division resulting from the use of the projection method. CadnaA - Reference Manual Chapter 6 - Calculation 6.1.3 Projection at extended Sound Sources 6 11 The next figure shows the projection method with a road. Projection method for a road Both axis of the outer road lanes - that is the margin of the road stripe in the CadnaA presentation - are first divided according to the shielding objects between receiver and road. Then a subdivision occurs according to the distance criteria. Projection method for reflecting sound parts Much more complicated are the relations in the projection of the reflecting sound parts dealt with in the next chapter. The figure 3 above shows the construction of both sections for the axis of the outer road lanes which are necessary because of the reflecting building. The same method - graphically hardly to explain - will also be applied by CadnaA for the multiple reflections dealt with further on. Although the projection method naturally extends the calculation considerably it should always be switched on for a detailed calculation like „acoustical zoom“. After all, even in the simple situation 12 paths of rays instead of 2 must be calculated. CadnaA - Reference Manual 6 12 6 Chapter 6 - Calculation 6.1.3 Projection at extended Sound Sources 6 CadnaA - Reference Manual Chapter 6 - Calculation 6.1.4 Reflection 6.1.4 6 13 Reflection Additional sound rays appear in the sector of the path of sound propagation from reflective objects which affect the receiver and could increase the sound level. The mirror-source method will be applied regularly by the calculation of reflection and it is therefore assumed that the reflective areas are „acoustically even“. In the experience of engineering the numerical calculation of diffuse reflection has only been achieved over the statistical approach for the density of scattering objects (see e.g. /96/). A numerically correct resolution for point-precise calculation with diffuse reflection is dealt with in /100/. But this is still a lavish resolution for the professional practice. On the other hand the mirror-source method has been proved excellent for the propagation of sound, also in cases strictly without even areas. The propagation of sound including reflection up to an extremely high order has been described precisely (see to this /101/ and /41/) for industry halls in which the surfaces areas are anything but even (through extensions such as pipelines and so on). CadnaA - Reference Manual 6 14 6 Chapter 6 - Calculation 6.1.4 Reflection 6 CadnaA - Reference Manual Chapter 6 - Calculation 6.1.5 Reflection of the 1st Order 6.1.5 6 15 Reflection of the 1st Order The calculation of the first reflection is required by certain standards if this reflection contributes to the sound level at the receiver (e.g. according to the guidelines RLS-90 /17/, Schall03 /23/ and ISO 9613-2 /8/). The calculation occurs in three steps which have to be carried out for each reflective area according to each pair source (Q) - receiver (IP). 1. constructing the position of the mirror sources, 2. sectioning the connecting line of the reflected source - receiver point with an area and determining the breakhrough-point, 3. calculating the part of the sound level according to the longer path of the ray over the reflecting area including the absorption coefficient of this area. In the example shown below two parts of sound level are taken into account at the receiver (IP) which are calculated from the displayed paths of rays. The paths of rays with the reflection of the first order CadnaA - Reference Manual 6 16 6 Chapter 6 - Calculation 6.1.5 Reflection of the 1st Order Important for the correct calculation of reflection, according to the mentioned guidelines, is that all reflections of the first order be checked and, if necessary, be included in the calculation. That is not obvious - software programs exist which check, starting at the receiver, a ray only till the first reflector crosses the path of the ray in the plan, even if this reflector is not affecting anything because of the low height and the area lying behind which reflects the ray. The calculation of reflection must, as in the example of picture A, also find a level-raising contribution if, as in picture B, a low obstacle at the base seems to block the ray’s path. 6 H=8m IP H=1m Q The paths of rays for the reflection of the first order with obstacles in the path of the ray. A typical example of this case is shown in the next figure. The program only investigates up to the first reflector which is found, then at the house on the left side of the road the amount of reflection which is caused by the high building is not taken into account only because a 1 m high wall is located between this high building and the four lane road. This calculation is not in accordance with RLS-90 in this case. CadnaA - Reference Manual Chapter 6 - Calculation 6.1.5 Reflection of the 1st Order 6 17 Besides this, CadnaA takes into account reflections if screening objects obstruct the path of the reflected sound ray. The part of the sound level which was caused by the reflecting sound at the receiver point is then reduced by the value which results from the screening calculation for the path: mirrorsource - receiver. 6 For the calculation of the sound level at the left residential building, according to RLS90, the reflection of the traffic noise on the high right building has to be calculated despite the low wall between the road and the building. CadnaA - Reference Manual 18 6 Chapter 6 - Calculation 6.1.5 Reflection of the 1st Order CadnaA also calculates the reflection for extended sources such as line or area sources, but these objects will be split into sufficiently small partial sources. The figure shows the already familiar soccer field with three buildings located in the neighborhood and the paths of rays taken into account. 6 The paths of rays taken into account in a calculation of sound levels on a soccer field CadnaA - Reference Manual Chapter 6 - Calculation 6.1.6 Reflections of Higher Order 6.1.6 6 19 Reflections of Higher Order In calculating reflections of second order all valid mirror-sources have to be reflected again on all reflecting areas to prove the validity of each reflection and to calculate the corresponding path of the ray. The number of rays with a further order of reflection results from the product of the number of reflections from the last order multiplied by the number of valid reflectors. The specification of this numeric method is found in / 100/. It is obvious that the number of possible reflections explodes with an increasing number of orders. Calculations up to higher orders are only completely possible for very restricted arrangements. On the other hand, a reflection has to be calculated first before its contribution can be evaluated as irrelevant. CadnaA enables the calculation of reflections of high orders for all type of sources. The paths of ray can be displayed and the sound level contributions of the reflections are separately identified. According to the specifications of the standards for the source type Road and Railway with activating these standards only reflection of first order are calculated using mirror-image method - reflections of higher order are taken into account with a penalty for multiple reflections. An example for the complete calculation of reflection up to the 10. order is shown with the backyard in the next figure. A point source located in front of the opening beams into the backyard, and the sound level shall be calculated at the represented receiver IP. CadnaA - Reference Manual 6 20 6 Chapter 6 - Calculation 6.1.6 Reflections of Higher Order Q 1.Ordnung Q 2.Ordnung 6 Q Q Q 3.Ordnung 5.Ordnung 7.Ordnung Q Q Q 4.Ordnung 6.Ordnung 8.Ordnung CadnaA - Reference Manual Chapter 6 - Calculation 6.1.6 Reflections of Higher Order Q 9.Ordnung Q 6 21 10.Ordnung All ray paths for each reflection order in a backyard 6 Q 0. - 10. Ordnung All possible ray paths of rays in a calculation up to the 10. order Arbitrary arrangements of objects can be taken into account for a calculation of reflections. With this technique it is possible to perform the calculation of the sound level corresponding to the reality in cases not corresponding to the valid guidelines. CadnaA - Reference Manual 22 6 Chapter 6 - Calculation 6.1.6 Reflections of Higher Order 6 CadnaA - Reference Manual Chapter 6 - Calculation 6.1.7 Displaying Sound Rays 6.1.7 6 23 Displaying Sound Rays When the option „Generate Rays“ is activated in the dialog Receiver all calculated rays with this target point are inserted as auxiliary polygon lines. With double-click on such a ray its contribution to the sound level at the receiver is indicated. This sound contribution is shown in the field „ID“ with its proportionate level, e.g., RAY_419_00 which signifies that the direct sound ray (_00) contributes 41.9 dB. The rays are shown on screen as if they cross screening objects straightly nevertheless screening is calculated taking into account vertical and lateral diffraction. In this case an s will be attached in their identifier. A shielded ray of the eighth order for which a calculation of diffraction has been enforced may have an identifier RAY_419_08s. Due to this, rays with a certain order of reflection can be displayed or switched off easily in CadnaA with the efficient group function (menu Tables|Groups see chapter 14.3 "Groups"). If the rays are displayed, all diffracted sound rays can be switched off in the representation by deactivating the group with the expression *_??s. With corresponding settings for all deactivated objects in Options| Appearance (see chapter 9.5 "Object Appearance") you can enforce the diffracted and non-contributed, mostly irrelevant rays to disappear completely. But the best is learning by doing - trace step by step the following example. • Start CadnaA • In Options|Limits enter the values for the limit as shown in the following dialog. CadnaA - Reference Manual 6 24 6 6 Chapter 6 - Calculation 6.1.7 Displaying Sound Rays Insert the following objects • Point source with PWL 100 dB, Name Q1 - coordinates 20/5/5 • 2 buildings with a height of 25 m and Reflection loss of 0 dB: - building 1 (80/60, 85/60, 85/100, 80/100) - building 2 (0/130, 5/130, 5/160, 0/160) • Click in the toolbox on the icon and enter the value 80 via the keyboard hereby an edit dialog opens to enter a polygon point - press the TAB key and enter the value 60 - confirm with OK and enter the next value for the second pair of coordinates. • After inserting the coordinates of the first building, quit the insertion mode by clicking with the right mouse button. • Again with the right mouse button, click once on the line of the building plan - the edit dialog opens. • Click on the button „Geometry“ and enter a building with a relative height of 25 m. • Repeat this for the second building. The building height is adjusted automatically. CadnaA - Reference Manual Chapter 6 - Calculation 6.1.7 Displaying Sound Rays • 2 Receiver points: I2 (35/110/5) and I3 (35/170/5) • Click on the corresponding icon in the toolbox • Enter the coordinate via keyboard and close the edit dialog Polygon Point by clicking OK • Open the edit dialog by clicking with the Right mouse key on the margin of the receiver point. • Confirm with OK. • In Calculation|Configuration|Reflection adjust a maximum reflection order of 2 or more The rays for the receiver I3 shall be displayed. • In the edit mode, open the edit dialog for receiver I3 by double-clicking on its border and activating the option „Generate Rays“. • Now start the calculation with a click on the Pocket Calculator symbol on the toolbar. The following representation occurs after the calculation. CadnaA has calculated the direct ray, a reflection of the first order and a reflection of the sec- CadnaA - Reference Manual 6 25 6 26 6 Chapter 6 - Calculation 6.1.7 Displaying Sound Rays ond order. (CadnaA calculates reflections completely up to the specified order - shall we bet that there are no more possible paths?) H o us e 2 I3 I2 H o us e 2 H o us e 1 I3 I2 Ho us e 1 6 S our c e situation S o ur c e after calculation and display of rays After double-clicking a ray - or by Tables|Other Objects|Aux.Polygon you can identify the rays on the basis of its ID, e.g., RAY_419_00 which means that the level contribution of this ray is 41.9 dB and the last two digits indicate the order of reflection. Double zero is the direct ray without reflection, 01 is a reflection of the first order, 02 of the second order and so on. CadnaA - Reference Manual Chapter 6 - Calculation 6.1.7 Displaying Sound Rays 6 27 Note the possibility in CadnaA in the tables - if you click on a data record, e.g., of the table Other Objects|Aux. Polygon the corresponding ray in the diagram will be marked and can easily be identified. Now only rays of the second order shall be displayed. This is in our example simplified by directly switching off the non-desired ray in the corresponding edit dialog on its ID field. But the deactivation of rays described in the following way is, however, with complex layouts the only realistic alternative. • Insert in Tables|Group a new table row (press the INS-key), doubleclick it and enter the expression *_02 in the same-named field and confirm with OK. • Insert a second line after the first one and enter the expression R*. • Deactivate this group (just enter a minus character - in the column Mark „M.“). After confirming with OK you will only see the desired group with rays of the second order. CadnaA - Reference Manual 6 28 6 Examples\06_Configuration\DisplayRays.cna Chapter 6 - Calculation 6.1.7 Displaying Sound Rays If the deactivated rays are displayed as bright grey dashes, let them disappear completely - this representation would still cover all activated rays in more complex situations. For this, use Options|Appearance| (deactivated) see chapter 9.5 "Object Appearance". To get to know the deleting of rays and the handling with shielded rays we recommend you do the following exercise. • Activate all groups again in Tables|Group • Click on the House 1 and copy it in a position with a left offset so that only a ray of the second order is intersected (see following figure) 6 House 2 I3 I2 House 1 Source Examples\06_Configuration\DisplayRays2.cna The rays need not to be deleted. Just restart the calculation and the rays are updated. Now start a new calculation - click on the Pocket Calculator in the icon bar. The ID of the ray which intersects the new building now contains the identi- CadnaA - Reference Manual Chapter 6 - Calculation 6.1.7 Displaying Sound Rays 6 29 fier RAY_220_02S. To eliminate only the shielded rays from the representation • insert a new row in Tables|Group, • enter *s in the field expression and deactivate this group. The screened ray has disappeared. 6 CadnaA - Reference Manual 30 6 Chapter 6 - Calculation 6.1.7 Displaying Sound Rays 6 CadnaA - Reference Manual Chapter 6 - Calculation 6.2 Configuration 6.2 6 31 Configuration In developing CadnaA, it was, and continues to be, our goal to give the professional user the desired freedom of choice and control while relieving those only interested in overall results from having to master all the available options. This complexity and flexibility of CadnaA is particularly evident when large stocks of data have been entered which are then to be processed under the Calculation|Configuration menu. To meet the requirements for the calculation according to EC-Directive on Environmental Noise CadnaA offers a flexible concept for defining and calculating evaluation parameters (see chapter 6.2.5). This concept enables to select from a number of pre-defined evaluation parameters (levels for single or combined time intervals) and some more specific parameters (such as the uncertainty Sigma). Furthermore, you may define your own evaluation parameters using formulas. In CadnaA up to four evaluation parameters can be calculated simultaneously, either for single receiver points or in a receiver grid (in addition to the ground). The dialog Calculation|Configuration serves to specify all settings required for the calculation, and, quite conveniently, to save these settings with the calculated project file. There are various tabs for groups of options within this dialog. Click the tab for the desired group to specify and select the options. CadnaA - Reference Manual 6 32 6 Chapter 6 - Calculation 6.2 Configuration 6 CadnaA - Reference Manual 6 33 Chapter 6 - Calculation 6.2.1 Country Tab 6.2.1 Country Tab 6 From the list box „Country“ a country’s name or a group designation is selected where specific standards or guidelines for all noise types are linked to. In the list boxes for „Industry“, „Road“, „Railway“, and „Aircraft“ the respective guidelines/standards used in a calculation are displayed. Country When selecting the option „user-defined“ from the list box „Country“ a calculation procedure - depending on availability - can be selected for each noise type individually. Please consider that not all standards/guidelines are linked to a group designation „Country“. Option „user-defined“ Depending on the actual selection the options available on the various configuration tabs differ. Via the buttons „Open Configuration“ and „Save Configuration“ the configuration settings (including all settings on all further tabs) can be opened and saved. see also chapter 14.7 Prototype File CadnaA - Reference Manual Open/Save Configuration 34 6 Chapter 6 - Calculation 6.2.1 Country Tab 6 CadnaA - Reference Manual 6 35 Chapter 6 - Calculation 6.2.2 General Tab 6.2.2 General Tab 6 Sound sources, whose contribution to the sound immission at the receiver point is negligible, will be ignored in the calculation if the overall error induced by this simplification is not larger than the defined value. Therefore, the larger the maximum permissible error in the final result, the shorter the time required for the calculation. max. Error (dB) In order to verify which sources can be ignored for a given maximum error, CadnaA applies the following procedure: Procedure • • • calculation of the partial levels of all sources based on the geometrical divergence only (e.g. Adiv of ISO 9613-2), sorting of the sources according to their partial levels, For example, with a maximum error of 1 dB, all sources that contribute less than this amount to the total sum level will be ignored. This calculation procedure occurs in two steps. The following examples have a grid of 50*50=2500 point sources with an Aweighted sound power level of PWL=100 dB(A) each. The rays of the sources considered in calculation and the result levels are displayed for maximum errors of 0, 1 and 2 dB. CadnaA - Reference Manual Example 36 6 Chapter 6 - Calculation 6.2.2 General Tab Examples\06_Configuration\General\max_error max. Error 0 dB resulting level 73.8 dB(A) All sources are taken into account (2500 rays). 6 max. Error 1 dB resulting level 73.6 dB(A) There are 2049 sources taken into account. max. Error 2 dB resulting level 73.2 dB(A) There are 1657 sources taken into account. CadnaA - Reference Manual 6 37 Chapter 6 - Calculation 6.2.2 General Tab From the calculation results it can be seen that the level difference compared with the resulting level at a maximum error of 0 dB is usually less than half of the error entered: maximum error dB(A) resulting level dB(A) difference dB 0 73.8 0 1 73.6 0.2 2 73.2 0.6 5 71.7 2.1 6 This difference is due to just considering of the geometric divergence Adiv when estimating the contribution of each source. Within the final calculation, however, further attenuation terms besides Adiv contribute to the overall attenuation reducing the effect on the resulting level. For expertise work (e.g. noise assessments for legal planning permissions and official approvals) a maximum error of 0 dB shall be used. For noise mapping or other major scenarios, a maximum error of 0 or 1 dB may be useful to reduce the computation time without sacrificing accuracy. The partial level of sources not considered in the calculation due to the maximum error are not listed on the table Partial Level of a receiver and not in the menu Tables|Partial Level (see chapter 5.1.2 and 14.3.2). Furthermore, the sources not considered are also not included in the calculation protocol (see chapter 6.5). CadnaA - Reference Manual Reasonable Values 38 6 Chapter 6 - Calculation 6.2.2 General Tab max. Search Radius (m) By the search radius, a circle is defined around the receiver point. Just the sources inside this circle will be considered in the calculation. Example The following examples show that just sources smaller than the search contribute to the receiver level. Examples\06_Configuration\General\max_search_radius search radius 300 m 6 search radius 500 m Default Value The default search radius is 2000 m. Depending on the project-specific conditions, a smaller or a larger radius may be useful. A small radius will reduce the calculation time, but may cause that dominant sources outside the search radius may not contribute. By a large search radius more or less all sources are included, but at the expense of a large computation time required without gaining any additional accuracy. CadnaA - Reference Manual Chapter 6 - Calculation 6.2.2 General Tab 6 39 A general value being useful for all kinds of scenarios cannot be given. The table below provides, however, some typical search radii for different scenarios: Scenario Typical Search Radius, value or value range (m) receivers close to source/s (industry, road, railway) 2000 city center with numerous sources (roads) 500 rural areas with a few main roads 5000 large-scale noise mapping projects 2000 to 5000 In any case, the radius shall be increased when loud and presumably dominant sources are located outside of the existing search radius causing level jumps (e.g. with the default search radius of 2000 m). Level jumps caused by single, dominant noise sources can be more easily revealed using the noise grid than being caused by numerous, spatially distributed sources. CadnaA - Reference Manual 6 40 6 6 Chapter 6 - Calculation 6.2.2 General Tab Min. Distance Source to Receiver The minimum distance source-receiver enables to suppress the calculation of propagation near the source. Within this vicinity of the source the same total attenuation as calculated at the minimum distance specified is used causing no increase in overall attenuation with distance in this area. Example The following example shows the grid appearance for the minimum distances of 0 and 20 m along a road. Examples\06_Configuration\General\min_distance_source_rcvr minimum distance source to receiver 0m (default setting) noise contours reach to the emission lines of the source (here: road) minimum distance source to receiver 20 m noise contours start from minimum distance (here in steps of 1 dB) CadnaA - Reference Manual 6 41 Chapter 6 - Calculation 6.2.2 General Tab In CadnaA you also have the possibility to evaluate the accuracy of noise prediction. This accuracy depends on the accuracy of the emission values used and the accuracy resulting from the calculation of propagation. Uncertainty In addition to the uncertainty of the emission data the uncertainty of the propagation can be taken into account (as e.g. caused by varying meteorological conditions). Enter an expression into the input box „Propagation Coefficient Uncertainty“. Propagation Coefficient Uncertainty Examples for expressions: Expression Remarks 3 dB global correction, i.e. no increase with distance d 3*log10(d/10) uncertainty depending on distance, uncertainty is 3 dB at 10 m distance, reference distance d0=10 m (Default) max(1, 2*log10(d/1)-3) based on a legal act when predicting the noise impact from wind turbines in the German state of Brandenburg, reference distance d0=1 m In addition to the operators (see chapter in CadnaA manual „Attributes, Variables, and Keywords“) the following additional attributes are available: • d: 3D-distance source-receiver • d2: 2D-distance source-receiver plus all further operators for expressions available in CadnaA. By default, the calculated sound levels are not altered just by specifying a standard deviation Sigma or a propagation coefficient uncertainty. This requires to select or enter a suitable parameter or expression on tab „Evaluation Parameter“ (see chapter 6.2.5). CadnaA - Reference Manual 6 Available Abbreviations 42 6 Standard Deviation Sigma Chapter 6 - Calculation 6.2.2 General Tab The source-specific uncertainty is specified by entering a standard deviation Sigma (dB) on the dialog Memo Window of each individual source. In case the sound power level of the source has been measured, the standard deviation for grades 1, 2 or 3 can be used (according to ISO 3740 series). 6 Dialog Memo-Window (accessible via each source dialog) Make sure that at least one of the evaluation parameters SigmaD/SigmaE/ SigmaN (for Day|Evening|Night) on the tab „Evaluation Parameter“ has been selected. The calculation of the Sigma values for single receiver (see chapter 5.3) occurs using the command Calculation|Calc or by clicking on the calculator symbol on the toolbar. The results are displayed on the dialog Receiver or on the Result Table (see chapter 11.2). The distribution of the uncertainty can be displayed as well on the grid resulting from a grid calculation (menu Grid|Calc Grid, see chapter 5.3). Samples\Infos\Uncertainty.pdf In /97/ it is shown how to evaluate the uncertainty of levels based on the uncertainty of sources and the uncertainty of propagation. The procedure using the data structure as implemented in CadnaA is demonstrated by an example. CadnaA - Reference Manual 6 43 Chapter 6 - Calculation 6.2.2 General Tab This option enables a seamless transition of the grid - regardless of the type of appearance selected (see chapter 5.3.2) - to the borders of closed polygons (such as of object types „Building“, „Area Source“, and „Parking Lot“). This is accomplished by interpolating the grid level values up to the first grid point inside polygon area. When calculating the levels at these grid points, the screening effect by the actual obstacle is not considered (i.e. an extrapolation of the free-field level occurs). This option is enabled by default. Extrapolate Grid ’under’ Buildings Examples Examples\06_Configuration\General\extrapolate_grid option activated: extrapolation occurs up to the 1st grid point laying inside the building option activated: as before, with transparent building and with grid values option deactivated: white gaps outside the building are due to the next grid point laying inside the building option deactivated: as before, with transparent building and with grid values CadnaA - Reference Manual 6 44 6 Chapter 6 - Calculation 6.2.2 General Tab It is recommended to deactivated the option „Extrapolate Grid ’under’ Buildings“ with the grid appearance option „Lines of Equal Sound Level“ selected in conjunction with the activated option „Exclude Buildings“ on menu Grid|Specifications|Options (see chapter 5.3.1). 6 Calculation of Terrain Height With the option „Extrapolate Grid ’under’ Building“ activated this also applies to the calculated terrain height level at each grid point Vertical Grid This option has no effect at vertical grids, i.e. there is no extrapolation of the grid calculated in the vertical plane grid in front of the facade the building’s interior area. Therefore, lower levels may be displayed - in particular with grid appearance options „Lines of Equal Sound Level“ and „Areas of Equal Sound Level“ - on the vertical grid in front of a facade grid due to the missing extrapolation to the building’s interior. CadnaA - Reference Manual 6 45 Chapter 6 - Calculation 6.2.2 General Tab If this option with the setting n*n is selected, the level calculation occurs starting at each of the (n+1) grid points as specified on menu Grid| Specification and at the center point of each rectangle delimited by those four points. Grid Interpolation 6 Option "Grid Interpolation": approach when the transition from a rectangle of size 9*9 to size 5*5 occurs If either of the following conditions are not met for each rectangle delimited by the four calculated points, this rectangle is subdivided into four equal squares and the check is repeated for each of these new four rectangles. If any of these conditions is still not met, a further subdivision occurs recursively until, in the end, the conditions are met or all grid points have been taken into account in the calculation based on the grid specification. The conditions are: 1. The difference between the largest and the smallest level calculated at the four corners of the rectangle is, at most, equal with the specified maximum value (default value: 10 dB). The default value of 10 dB ensures that - in case of significant extra attenuation between the corners (e.g. by large obstacles) - a further subdivision occurs. CadnaA - Reference Manual Conditions 46 6 6 Chapter 6 - Calculation 6.2.2 General Tab 2. The mean level calculated from the levels at the two corner points of each diagonal shall not differ from the level at the center point by more than the specified maximum deviation (default value: 0.1 dB). This condition must be fulfilled for both diagonals. The default value of 0.1 dB is - in general - exceeded if additional attenuations on the diagonals between the corners and the center are caused, e.g. by a screening obstacle. When these conditions are fulfilled, the interpolated values inside the rectangle match sufficiently with the real values and the levels at the remaining grid points inside the rectangle are interpolated from the levels calculated at the four corner points. CadnaA - Reference Manual 6 47 Chapter 6 - Calculation 6.2.2 General Tab When selecting this option, an approximative method for the screening calculation when using RLS90 or Schall03 (1990) is applied causing an acceleration of the screening calculation. In this case, however, the calculation applied is longer compliant with those guidelines. Fast Screening Do not use this option with other calculation standards or source types (in particular not with point, line and area sources) as this may cause irregular results. By this procedure, no detailed calculation by scanning each for each obstacle in the ray’s path occurs, but a given parabolic ray path is used. Only those buildings exceeding this path will contribute to the screening effect while the others are not even checked for. In the vertical cross-section (see chapter 9.12) only those obstacles are shown contributing to the screening effect. Those not being intersected by the ray path are not displayed. "fast screening" activated: On the sectional view of a ray only a limited number of obstacles are displayed (detailed section near the source). "fast screening" deactivated: On the sectional view of a ray all obstacles are displayed as all are included in the screening calculation (detailed section near the source) CadnaA - Reference Manual 6 48 6 Chapter 6 - Calculation 6.2.2 General Tab Calculation Strategies There are two kinds of calculation strategies applied in noise prediction software, the ray-tracing method or the angle scanning method. CadnaA is the only software program offering both methods. The ray-tracing method is used in CadnaA by default. Ray Tracing (RT) The ray paths between sources and receivers are constructed in a deterministic way. Extended sources are subdivided dynamically applying the projection method. The source segments represented by a single ray are shorter at small receiver distances and large at large receiver distances. Screening objects and all gaps between them produce at least one single ray (see also chapter 6.1.3). With the option „Angle Scan Method“ deactivated (see below) the ray-tracing method is used. 6 Ray-Tracing with projection to subdivide extended sources dynamically Angle Scanning (AS) With the option „Angle Scan Method“ activated the procedure described in the following will be used. In this case, the calculation of the receiving levels is carried out using rays emitted at constant angular steps, starting from the receiver point to the source. Only those objects intersected by the ray’s path contribute to the screening effect. Point sources situated within the angle cone are virtually transferred to the ray’s path. CadnaA - Reference Manual 6 49 Chapter 6 - Calculation 6.2.2 General Tab 6 Angle Scanning Method: Rays start from the receiver and are spaced at equal angular steps • Number of Angle Segments: default value 100, resulting in 360°/ 100=3.6° steps between rays • Reflection depth: With a reflection depth of zero, obstacles behind the first reflector in direction of the ray are not seen, irrespective of the reflection order specified and when the first reflector detected was not reflective, based on its dimensions. Thus, the specification of the reflection depth represents the number of potential reflectors which can be ignored in ray direction because of their dimensions. However, at least a single additional reflector is taken into account in any case. Example: In order to detect reflector no. 4, a reflection depth of at least 3 must be specified. With the option „Angle Scan Method“ activated the settings on the „Partition“ tab are no longer relevant (see chapter 6.2.3). CadnaA - Reference Manual Options 50 6 Mithra Compatibility Chapter 6 - Calculation 6.2.2 General Tab When the option „Mithra Compatibility“ is activated, all the approximations used in the software Mithra are also used in CadnaA-Mithra. This is the mode that should be used to load MITHRA projects using CadnaA-Mithra and to obtain the same as with MITHRA. 6 The check box is only available if the option CadnaA-Mithra has been purchased. Within the MITHRA compatible calculation - among others - additional screening will be taken into account, see the barriers with special crowning in CadnaA-Mithra (see chapter 3.2.2). CadnaA - Reference Manual 6 51 Chapter 6 - Calculation 6.2.3 Partition Tab 6.2.3 Partition Tab 6 At line and area sources, the largest dimension of a section Hmax generated by segmentation is smaller than the raster factor multiplied with the distance d of the center point of the section from the receiver. A raster factor of 0.5 is used per default: Raster Factor Hmax < 0.5 * d The smaller this factor, the more sub-segments of the source/s are generated and the more computation time is required. Upon calculation the software checks, based on shortest distance between a receiver (or a grid point) and any source, whether the entered geometry of each source section respects the defined segmentation rule. If not, the corresponding source section is halved and the check is repeated. This continues until the defined segmentation rule is respected. CadnaA - Reference Manual Procedure 52 6 Examples\06_Configuration\Partition\raster_factor Chapter 6 - Calculation 6.2.3 Partition Tab The following example shows the segmentation of a line source of 200 m length using two different raster factors for a receiver at a perpendicular distance of 100 meters from the center of the source. Raster Factor 0.5 6 The required segment length is respected with four segments because it holds: 50 m < 125/2 m or resp. 50 m < 103.1/2 m Raster Factor 0.1 The required segment length causes three or four division steps resp.: - for the 6.25 m segments: 6.25 m < 100/ 10 m or 6.25 m < 123.2/ 10 m - for the 12.5 m segments: 12.5 m < 128.8/ 10 m or 12.5 m < 137.1/ 10 m CadnaA - Reference Manual 6 53 Chapter 6 - Calculation 6.2.3 Partition Tab The maximum and minimum section length (in meters) resulting from the automatic segmentation can be specified. The entered values serve as an additional criterion besides the grid factor. By the segmentation method, no larger source segments as the maximum section length and no smaller than the minimum segment length produced. Maximum/Minimum Length of Section (m) The following examples use a raster factor of 0.5. Examples\06_Configuration\Partition\max_section_length maximum length of section 1000 m (default value): In this example without any effect as all segment lengths are < 1000 m. maximum length of section 25 m: All source segments have segment lengths smaller than 25 m. Smaller section lengths arise depending on the raster factor. CadnaA - Reference Manual 6 54 6 Minimum Length of Section (%) Chapter 6 - Calculation 6.2.3 Partition Tab The minimum section length can also get specified as a percentage of the total length. If the minimum segment length is not 0% the higher value of „Min. Length of Section (m)“ and „Min. Length of Section (%)“ is used. Examples\06_Config6 uration\Partition\min_section_length Specifying a percentage can speed up the calculation considerably, as with extended and large-area sources less rays from sub-segments are produced. The subsequent examples use a grid factor of 0.5 and a maximum section length of 1000 m. minimum section length 1 m (default) and 0%: There are 14 source segments generated with the section lengths 125, 62.5 and 31.25 m. minimum section length 100 m and 0%: There are 12 source segments generated with the section lengths 125 and 62.50 m. The four sections having a length of 31.25 m have been replaced by two sections with a length of 62.50 m in order to fulfill the condition: 62.5 m < 100 m. Partition according to RBLärm-92, Proc. 1 The procedure 1 is the so-called "precise" method according to /20/ yielding sections as long as possible. This option is just relevant to German road noise assessments. CadnaA - Reference Manual 6 55 Chapter 6 - Calculation 6.2.3 Partition Tab With the option „Projection“ activated, prior to the segmentation of sources, a pre-partitioning for line and area sources occurs subdividing the source into screened and unscreened parts. After this subdivision the screened and unscreened parts of source are segmented separately based on the distance criterion (see chapter 6.1.3). Projection of With this option, even the terrain being modeled from terrain contours is considered within the projection procedure of line and area sources. This option is disabled by default. Projection at Terrain Model When this option is enabled the terrain contour lines resulting from the triangulation are ignored when deciding which terrain contours provide screening or not. 6 Examples\06_Configuration\Partition\projection_DTM Projection at Terrain Model OFF: The screening of the line source line by the ter- rain (with a top edge at 20 m height) is not considered the projection. CadnaA - Reference Manual 56 6 Chapter 6 - Calculation 6.2.3 Partition Tab 6 Projection at Terrain Model ON: In the projection, the part of the line source shielded by the terrain (orange rays) is segmented separately from the non-screened part. Maximum Distance Source-Receiver If the receiver point is further away than this maximum distance no projection is applied (default distance: 2000 m). Search Radius Source When partitioning sources using the projection only obstacles which are taken into account within this distance from the source (default radius: 100 m). Search Radius Receiver When partitioning sources using the projection only obstacles which are taken into account within this distance from the receiver (default radius: 100 m). CadnaA - Reference Manual Chapter 6 - Calculation 6.2.3 Partition Tab With activation of this option the projection method will not generate smaller sections as specified for the „Min. Length of Section“. The larger value of „Min. Length of Section (m)“ and „Min. Length of Section (%)“ will be used. 6 57 Min. Lengths are considered by projection Activating this option can accelerate the computation. Examples\06_Configuration\Partition\min_section_length_projection 6 option „Min. Lengths are considered by projection“ ON option „Min. Lengths are considered by projection“ OFF: The rays in orange color shown above do not occur with the option activated. CadnaA - Reference Manual 58 6 Chapter 6 - Calculation 6.2.3 Partition Tab 6 CadnaA - Reference Manual Chapter 6 - Calculation 6.2.4 Reference Time Tab 6.2.4 6 59 Reference Time Tab 6 The reference time specifies the time interval for the calculation of the average sound pressure level considering the actual operating time of the source with respect to the basic evaluation requirements. The specification of a reference period is always required when the emission from different periods Day/Evening (Recreation Time)/Night D/E/N shall be combined to a mixed evaluation level (e.g. Lden, Lde). In general, penalties for noise-sensitive daily periods are used to account for the increased noise effect (annoyance) when calculating such mixed evaluation levels. CadnaA - Reference Manual Reference Times and Penalties 60 6 Chapter 6 - Calculation 6.2.4 Reference Time Tab Dialog Options Allocation Hours - Periods On the upper part of the „Reference Time“ tab the 24 daily hours are allocated to the periods. Each hour can be assigned to one of the daily periods Day/Evening (Recreation Time)/Night by entering a letter (D, E or N, uppercase or lowercase). This flexible concept enables to meet all the requirements of the EC Environmental Noise Directive (also when possibly shortening the Night period and the lengthening the Day and/or Night period). 6 If individual hours are not to be taken into account, the relevant box can be left blank (see examples below). The reference periods defined apply to all noise types and affect the mixed evaluation levels such Lden and Lde (see chapter 6.2.5). For the non-mixed evaluation levels (such as Ld, Le and Ln) no time correction and no penalty is considered. The following rules apply depending on the different noise types: • industrial sources: The reference periods will be considered only when on the source dialog the option „Operating Time (min)“ has been selected with operating times specified or when diurnal pattern has been selected (see chapter 2.1.1). • road: Depending on the selected calculation standard the receiving level is just calculated for day and night only. In order to perform calculations involving the allocation of hours (e.g. for the EC Environmental Noise Directive) diurnal patterns for roads have to be used - if the selected road noise standard does not provide traffic volumes for the periods D/E/N distinctively (see chapter 2.4, for each road standard, and chapter 6.2.10). • railroad: as with road, applying the option „Use Non-Standard Reference Time D/E/N“ (see chapter 2.6, for railway standard, and chapter 6.2.11). • aircraft noise: see railroad (for „Aircraft Noise“ tab see manual FLG) CadnaA - Reference Manual 6 61 Chapter 6 - Calculation 6.2.4 Reference Time Tab The calculation of the noise indicators Lden and Ln according to the EC Environmental Noise Directive is possible with the standard version of CadnaA. By contrast, the evaluation of noise levels statistics with respect to the number of exposed inhabitants requires the evaluation method „Object-Scan“ provided by the CadnaA option X or XL. Penalties are only taken into account for mixed evaluation parameters, such as Lden or Lde. Enter the required penalties according to the applying legal requirements. For example, according to the definition of Lden enter penalties for the period „Evening/Recr. Time Penalty“ of 5 dB and for the period „Night“ of 10 dB. Penalties Recreation Time Penalty only for This option refers the a specific part of German legislation requiring to apply the recreation time penalty only to „general“ and „pure“ residential areas, but not for mixed or industrial areas. In contrary, this option is on most or all other countries no required and has to be deactivated. If this option is activated, select the types of land use for which recreation time penalty shall be considered. This selection requires that • objects „Area of designated Land Use“ have been entered in the project and a type of land use therein has been selected, or • receivers have been entered with a type of land use assigned. CadnaA - Reference Manual 6 62 6 Chapter 6 - Calculation 6.2.4 Reference Time Tab Examples for Reference Times & Penalties No Settings on „Reference Time“ tab 1 6 plus: land use type specific recreation time penalty activated Remarks To consider the loudest hour during the night only one letter N is entered in the allocation of hours. In this case, the operation time entered during the night is the operating time (min) of the source during this single hour. For the periods „Day“ and „Evening/Recreation Time“ the operating time refers to the reference times 13 h D (= 960 min) and 3 h E (= 180 min). The penalty for „Evening/Recreation Time“ is 6 dB. The surcharge 10 dB for Night is irrelevant since there is mixed level be used combining the night period; the evaluation parameters are Lde and Ln. 2 Alternatively, in order to determine the loudest hour during the night, the letter N is entered for all hours of the night and the evaluation parameter L1hMaxN is selected (see chapter 6.2.5). This requires, however, that for each relevant industrial source a specific diurnal pattern is defined and addressed via the source‘s dialog. The further settings are as for No.1; the evaluation parameters are Lde and L1hMaxN. 3 In order to perform calculations according to the EC Environmental Noise Directive the following allocation of hours is assumed: 12 h D (starting at 6 o‘clock), 4 h E (starting at 18 o‘clock) and 8 h N (starting at 22 o‘clock). The penalties are 5 dB for „Evening (Recreation Time)“ and 10 dB for „Night“. Both penalties are relevant when calculating the day-evening-night noise index Lden, not however, for the night-time noise index Ln. CadnaA - Reference Manual 6 63 Chapter 6 - Calculation 6.2.4 Reference Time Tab No „Reference Time“ tab 4 5 Remarks similar to No. 3, but the Day period has been extended to 14 hours (from 6 to 20 o‘clock). The extended Day period does not receive a penalty when calculating Lden. The shortening of the Evening period by 2 hours and the corresponding lengthening of the Day period corresponds with the provisions of the EC Environmental Noise Directive (/121/, Annex I). In case source-specific operating times are used, those - as before - refer to the above mentioned periods. The allocation of hours just uses the letters D and N. Thus, an Evening period does not exist. The mixed level Ldn is assessed by adding a penalty of 10 dB for „Night“. Further, the Night level Ln calculated. The specified penalty for „Evening/Recreation Time“ of 5 dB is irrelevant. Regarding the option „Special Reference Times for Industry (min)“ on the „Reference Time“ tab of former releases of CadnaA see chapter 6.3. CadnaA - Reference Manual Adjusting the configuration 6 64 6 Chapter 6 - Calculation 6.2.4 Reference Time Tab 6 CadnaA - Reference Manual Chapter 6 - Calculation 6.2.5 Evaluation Parameters Tab 6.2.5 6 65 Evaluation Parameters Tab 6 CadnaA offers a flexible approach to define the evaluation parameters to be calculated, such as individual levels (e.g. Ld, Ln) or level for combined periods (e.g. Lden, Lde), the uncertainty Sigma (for Day/Evening/Night) or for userdefined expressions. The following evaluation parameters can be selected by default: • • • • levels for individual daily periods D/E/N: Ld, Le, Ln levels for combined daily periods: Lden, Lde, Len, Ldn uncertainty for daily periods D/E/N: SigmaD, SigmaE, SigmaN loudest hourly level in the daily periods D/E/N: L1hMaxD, L1hMaxE, L1hMaxN and • formula expression „=f(x)“: total level or noise-type specific level, Day/ Evening/Night, single value or spectrum, total or in octaves, linear/A-/ B-/C- or D-weighted. Formula expressions can be defined using the CadnaA specific operators (see chapter 1.1 in the manual „Attributes, Variables, and Keywords“). Furthermore, the following aircraft noise specific levels and evaluation parameters are available (requires option FLG): CadnaA - Reference Manual 66 6 Chapter 6 - Calculation 6.2.5 Evaluation Parameters Tab • • • • • 6 the number of events (e.g. flight movements) above a threshold level: NATd, NATe, NATn, the uncertainty for the number of events (e.g. flight movements) above a threshold level: SigmaNATd, SigmaNATe, SigmaNATn, the resulting level of the maximum level evaluation for aircraft noise: FlgStatD/E/N, the standard deviations of the resulting level of the maximum level evaluation for aircraft noise: SigFlgStatD/E/N, and the so-called „effect related substitute level“ (see chapter 6.6.1) according to the VDI guideline 3722-2 /44/ for the evaluation parameters Lden (DEN) and Ln (Night). As long as no formula expression f(x) is used to exclude certain noise types from calculation all selected evaluation parameters are calculated including all types of sources, provided these sources are active. The result levels are calculated for up to evaluation parameters at individual receivers or facade points (using the building evaluation symbol), as well as on the horizontal or vertical grids (besides the ground). Dialog Options List Box „Type“ Select from the list box „Type“ the evaluation parameter to calculate. In dialogs and tables showing calculation results (e.g. on the dialog Receiver) up to four evaluation parameters are displayed. • Example: The evaluation parameter for calculation according to the EU Environmental Noise Directive are the day-evening-night index Lden and the night index Ln. In formulas or expressions that attribute names LP1 to LP4 are used for establishing a reference to the evaluation parameters (see chapter 1.1 in the manual „Attributes, Variables, and Keywords“). By default, the daytime level Ld and the nighttime level Ln are set. CadnaA - Reference Manual 6 67 Chapter 6 - Calculation 6.2.5 Evaluation Parameters Tab After activation of the input box „Name“ a user-defined expression (alias name) can be entered for the selected evaluation parameter (e.g. „Day“) which will be displayed instead of the name selected on the list box „Type“. Input Box „Name“ List box „Type“ with parameter Lde selected, and activated field Name with an entered user-defined alias „Day“. 6 Dialog Receiver showing three evaluation parameters, for LP1 an alias name has been entered Additionally in the box „Unit“ you may enter an identifying item (e.g. dB(A) or sigma) which will also be displayed if the check box is activated. After activation an appropriate unit can be entered, being used for display that also appears in dialogs and tables showing results. Otherwise, „dB“ is displayed for unit. In particular, this option is useful in conjunction with a formula expression f(x) (see below), since by a formula any kind of result can be generated, the unit of which is not necessarily more expressed in decibels. CadnaA - Reference Manual Input Box „Unit“ 68 6 Input Box „Expression“ Chapter 6 - Calculation 6.2.5 Evaluation Parameters Tab After selecting the formula symbol „=f(x)“ from the list box „Type“ a userdefined formula expression or a predefined expressions (see double arrow ) can be selected or entered. In formula expressions the CadnaA specific operators can be used (see chapter 1.1 in the manual „Attributes, Variables, and Keywords"). By the expression „indd“ the A-weighted noise level Ld will be calculated just for industry sources. 6 Clicking the double arrow opens a cascading list of predefined expressions. Select the corresponding parameter from the list. Error Condition In case an error occurs within a user-defined expression the value -88 will result for that evaluation parameter. CadnaA - Reference Manual 6 69 Chapter 6 - Calculation 6.2.5 Evaluation Parameters Tab • The selections „Single Value“ and „Loudest Hour“ include all active sources or all active sources of a source group, with non-spectral and spectral emission. • By contrast, the selections „Spectrum|Total (linear//A-/B-/C-/Dweighted)“ include the active sources or the active sources of a source group with spectral emission only. Both notes above cause that when having non-spectral and spectral sources in a project, a level difference occurs between the two abovementioned selections (e.g. between the A-weighted sum level as „Single Value“ (totd) and the A-weighted sum level of the spectral sources only („Spectrum|Total|A-weighted“, totd_a). • In case a mixed level shall be used as an evaluation parameter (e.g. „Lden+3 dB“ or „Lde_road-3dB“), it is always required to enter the entire formula because mixed levels are not available as predefined expressions. • Conditions can be used in expressions (operator „iif“ as IF..THEN..ELSE loop; see the subsequent example section). Note that just numerical expressions may be used in formulas. In particular, no strings can be used in a condition or as a result of a condition. • Use just the parenthesis „()“ to define nested expressions. Other types of brackets meet the error condition. • In order to separate variables in expressions just use the comma. Other separators (e.g. the semicolon) meet the error condition. • Extra spaces within expressions are harmless and do not meet the error condition. By contrast no spaces are allowed between an operator and its opening parenthesis [thus „iif(...), not „iif_(...) with „_“ representing the space]. CadnaA - Reference Manual Notes for user-defined expressions 6 70 6 Chapter 6 - Calculation 6.2.5 Evaluation Parameters Tab Examples for expressions 6 Expression Remarks totd+3 addition of 3 dB to the total level Day strd++schd energetic summation of level Road Day and level Railroad Day totn_2l++totn_3l++totn_4l energetic summation of the linear total octave level from 125, 250 and 500 Hz (octave-No. 2, 3 and 4) indd-strd level difference between the level Industry Day and Road Day totd+1.65*sigmad upper limit of the Daytime-level at 95% single-sided confidence interval („level that is not exceeded at a statistical confidence level of 95%“) iif(totd>50, totd, 0) if the total level Day > 50 dB it will be displayed, otherwise zero iif(totd>50, 0, totd) if the total level Day > 50 dB zero, otherwise the total level Day will be displayed flgd + 3*sigmad aircraft noise level Day + 3 * standard deviation Day flgn + 3*sigman aircraft noise level Night + 3 * standard deviation Nigh natn + 3*sigmanatn number of exceedances of the threshold level for aircraft noise Night + 3 * standard deviation of the number of exceedances Night NOTE - The threshold level for NATs (dB) is specified on the „Aircraft“ tab. Adjusting the configuration Regarding the option „Compatibility Mode for Industry“ on the „Evaluation Parameters“ tab of former releases of CadnaA see chapter 6.3. CadnaA - Reference Manual 6 71 Chapter 6 - Calculation 6.2.6 DTM Digital Terrain Model Tab 6.2.6 DTM Digital Terrain Model Tab 6 The standard height defines the absolute terrain height to be used in the calculation when no other information of the actual terrain height is available. This applies to areas in the model which are not covered by distinct contour lines or height points (for example, at the corners of the limits, see chapter 9.1). Based on this standard height and the terrain model all objects having a relative height get assigned an absolute height. The predefined standard height is 0.00 m. Standard Height (m) The following options for the generation of terrain models are available: Model of Terrain By triangulation a terrain model consisting of triangles is generated from the entered height points (see chapter 4.1.2) and the polygon points of terrain contours (see chapter 4.1.1) and lines of fault (see chapter 4.1.3), if any. In this case, no ground grid needs to be calculated in order to display the terrain shape in the 3D-Special view (see chapter 9.14). Triangulation The triangulation is the contemporary used method to generate a digital terrain model. CadnaA - Reference Manual 72 6 Chapter 6 - Calculation 6.2.6 DTM Digital Terrain Model Tab Explicit Edges Only When activating the option „Explicit Edges Only“, only the entered terrain contours will cause a screening effect and not the terrain edges resulting from triangulation. This option has no effect on the 3D-Special view. Objects with ’Ground at every point’ influence DTM Activating this option will cause the height of the base point of objects with a height using the option “absolute Height/Ground at every Point“ will determine the terrain height at that location upon triangulation. 6 The options „Search Contour Lines (Average)“ and „Search Contour Lines (Local Inclined Plane)“ were available in former versions of CadnaA - before the triangulation method was introduced. These options are kept primarily for reasons of backward compatibility ans should not be used for new projects. Search Contour Lines (Average) This option generates a terrain model by assessing the contour lines regarding the squared distance and by averaging. Search Contour Lines (Local Inclined Plane) This option approximates a terrain model by inserting planes between the existing terrain contours and height points. Search Radius for Contour Lines (m) In order to determine the local terrain height, all terrain contours within this radius will be considered. The larger the search radius, the longer the calculation time will be. Displaying triangulated terrain contours The terrain contours resulting from triangulation can be displayed. Select the command Properties from the Options menu. Specify a line type for the object type „Triangulation“ on dialog Appearance (see chapter 9.5). By default, triangulated lines are not displayed. CadnaA - Reference Manual 6 73 Chapter 6 - Calculation 6.2.6 DTM Digital Terrain Model Tab Normally, the triangulation method generates a terrain model which leads to realistic approximations of the terrain at locations between the existing terrain contours and height points. The terrain contours resulting from the triangulation cause a screening effect in the calculation by default. With the option „Objects with ’Ground at every point’ influence DTM“ activated, also these objects determine the local terrain height and thus the position of the resulting edges of the triangles. General information on terrain models The closeness to reality of a numerically generated terrain model applying the triangulation method depends also on a sufficiently dense sequence of terrain contours and height points. With too large distances between points defining the height, cause a relatively coarse terrain model results with large triangles, each being a plane surface. 6 for more information see Chapter 4 - Topography With this option enabled, the height of sources which are below ground level is lifted to a relative height of 0 m within the calculation. This holds for line and area sources as well, causing the sub-sources resulting from segmentation to be raised to a relative height of 0 m. With traffic sources (road, railway and parking lot) the absolute height of the sub-sources is increased by the source height specified by the respective standard or guideline (for example, by the source height of 0.5 m for RLS-90 and 0.6 m for Schall 03). In any case, the (absolute) height used in the calculation is listed on the protocol of receivers (see chapter 6.5). The specified object height and the terrain model itself will remain unchanged. It is recommended to use this global option after importing digital data from external data sources only. In general, any inconsistencies between the object’s geometry data and the terrain model shall be avoided by checking the project thoroughly. CadnaA - Reference Manual Lift ’Sources under Ground’ to GroundNiveau 74 6 Area sources with constant relative height follow terrain 6 Chapter 6 - Calculation 6.2.6 DTM Digital Terrain Model Tab With this option enabled, the geometry of area sources and parking lots will be split into triangles according to the entered triangulated terrain contour lines. The new object geometry is displayed on the 3D-Special view. Regardless of whether the sound power level PWL or the area related sound power level PWL“ is specified as emission data in the source dialog, the resulting value of the not specified emission level is based on the total area of the 3D-surfaces of all fitted triangles. This sum does not match the 2D-area displayed on dialog Polygon:Geometry of the source, as this is the projected area. Example option deactivated: The parking lot is covered by the terrain as the parking lot’s polygon is outside the terrain contours. option activated: The parking lot is fitted to the terrain’s shape. In the example above, the command „Fit Object to DTM“ from the parking lot’s context menu (see chapter 11.24 in the manual „Introduction to CadnaA“) would not cause any effect, because the parking lot’s polygon does not intersect with any of the entered or triangulated terrain contour lines. CadnaA - Reference Manual 6 75 Chapter 6 - Calculation 6.2.7 Ground Absorption Tab 6.2.7 Ground Absorption Tab 6 When calculating the ground absorption the global ground absorption for areas not covered by the object "Ground Absorption" (see chapter 3.4) can be defined here (0 <= G <= 1). By default, a value of G=1 is assumed (porous soil). Default Ground Absorption G It can be selected whether the map of ground absorption shall be used or not. This option is useful when having numerous areas of ground absorption in the project. In this case, the map of ground absorption accelerates the calculation because this map is used instead of the list of areas. The following options are available: Use map of ground absorption • • • • No: The existing areas of ground absorption are used within the calculation. Yes: The map of ground absorption is used in any case. Automatic (Default): Provided that all ground absorption areas in the project have more than 100 polygon points the map of ground absorption is generated and used. Otherwise the areas of ground absorption are used. Resolution (m): resolution of the ground absorption grid (default value: 2 m) CadnaA - Reference Manual 76 6 Chapter 6 - Calculation 6.2.7 Ground Absorption Tab Roads/Parking Lots are reflecting (G==0) With this option activated, the road region (road width plus additional width (from dialog Appearance), or additional width from self-screening) will be considered as globally reflecting in the calculation. Whether this setting has any effect depends on the selected calculation standard or guideline. Buildings are reflecting (G==0) With this option activated, the base area of buildings (road width plus additional width (from dialog Appearance), or additional width from selfscreening) will be considered as globally reflecting in the calculation. Whether this setting has any effect depends on the selected calculation standard or guideline. Railways are absorbing (G==1) With this option activated, the road region (road width plus additional width (from dialog Appearance), or additional width from self-screening) will be considered as globally absorbing in the calculation. Whether this setting has any effect depends on the selected calculation standard or guideline. 6 CadnaA - Reference Manual Chapter 6 - Calculation 6.2.8 Reflection Tab 6.2.8 6 77 Reflection Tab 6 In order to perform calculations involving reflections, the following settings are required: 1. On the „Reflection“ tab (menu Calculation|Configuration), the maximum order of reflection to be calculated is set (non-zero). 2. Make sure that all objects to be considered in the calculation of reflections (e.g. buildings, barriers, cylinders, 3D-reflectors) are reflective (see chapter 3.1). CadnaA calculates reflections applying time-efficient algorithms to detect all possible ray paths up to the order specified. However, the required computation time increases with increasing order of reflection and with increasing number of reflective objects. High reflection orders used in conjunction with large scenarios may lead to unacceptable computation times. A calculation of higher orders of reflection should, therefore, only be used with limited scenarios and with a few reflective objects. CadnaA - Reference Manual 78 6 max. Order of Reflection Chapter 6 - Calculation 6.2.8 Reflection Tab The maximum order of reflection to be taken into account using the image source method, basically determines the calculation time. For most tasks it is sufficient to just consider the first order of reflection. Higher reflection orders should be used only with limited scenarios comprising a fewer number of objects. Default Setting: 0 Order (direct rays only). 6 Several guidelines and standards for the calculation of road and railway noise (e.g. RLS-90 /17/ or Schall03 /23/) just consider reflections up to the first order. When the options „Strictly acc. to RLS-90“ (see chapter 6.2.10) and/or „Strictly acc. to Schall03“ (see chapter 6.2.11) are activated on the „Road“ resp. „Railroad“ tabs, the setting for the reflection order on the „Reflection“ tab is ignored. In these cases, the calculation is performed only up to and including the first order. At present, CadnaA calculates reflections up to a maximum order of 20. CadnaA offers to display the ray paths contributing to the level at a receiver (see chapter 6.1.7). CadnaA - Reference Manual 6 79 Chapter 6 - Calculation 6.2.8 Reflection Tab Conditions for Calculation of Reflection Up to this distance in meters from the source or from the receiver all the reflective surfaces are detected (default value: 100 m). Search Radius from Source/from Receiver When this input box is empty or when the value is 0, no test for reflective surfaces occurs. Examples\06_Configu setting: up to 1st order, 100 m radius from source and from receiver: All barriers which are located entirely or partially within the two search radii have been detected, provided they have reflective properties and satisfy the reflection condition. setting: up to 1st order, 150 m radius from source, 0 m from receiver: The northerly, reflective barrier is detected as well. The easternmost barrier is outside the search radius of the source. CadnaA - Reference Manual ration\Reflection\search_r adius_reflector 6 80 6 Maximum Distance Source - Receiver Chapter 6 - Calculation 6.2.8 Reflection Tab When the receiver is further away from the source than the maximum distance, no reflections will be calculated. This requirement is checked for in addition to the specified search radius for source and receiver (default value: 1000 m). Examples\06_Configuration\Reflection\max_distance_source-rcvr 6 settings: - maximum distance source-receiver 1000 meters - calculation up to 1st order of reflection - 100 m radius around source and receiver: The reflector is only seen by the receiver at distance x = 500 m, since there the reflector is within the 100 m radius around the receiver and less than 1000 m away from the source. By all the other receivers the reflector is not seen. settings: as before The reflector is not seen by the receiver at distance x = 1100 m because it is more than 1000 m away from the source. The reflector is seen by the receiver at x = 999 m, since the latter is less than 1000 m away from the source and the reflector lays within the search radius of 100 m around the source. CadnaA - Reference Manual 6 81 Chapter 6 - Calculation 6.2.8 Reflection Tab This option offers to interpolate between the region having been calculated with and that region having been calculated without reflections. Interpolation between these regions is particularly useful with grid calculations in order to avoid level jumps at the border of both regions. • The default value is 1000 m. So, no interpolation occurs as there is no transition region (i.e. the value „Interpolate from“ equals the value „Max. Distance Source-Receiver“). • When the value „Interpolate from“ is less than 1000 m (assuming the default maximum distance source-receiver of 1000 m) the effect due to reflection is continuously decreased in the intermediate region. In the examples the maximum distance source-receiver is 1000 m. All other settings correspond to the default setting. value for "Interpolate from" = 1000 m: The level increase due to reflection visible on the grid in front of the reflecting barrier suddenly ends at a distance of 1000 m (corresponding to the maximum distance source-receiver of 1000 m). value for "Interpolate from" = 500 m: In the distance range from 500 to 1000 m from the source, the level is interpolated linearly, so that no level changes occur on the grid. CadnaA - Reference Manual Maximum Distance Source - Receiver, Interpolate from 6 Examples\06_Configuration\Reflection\max_distance_source-rcvr 82 6 Minimum Distance Receiver - Reflector Chapter 6 - Calculation 6.2.8 Reflection Tab When calculating the facade levels at buildings (by using receivers or facade points in conjunction with the Building Evaluation, see chapter 5.4) national regulations specify whether these levels have to be calculated including the reflection by the facade or not. When the calculation of the facade level does not consider the reflection, the minimum distance receiver - reflector specified here must to be larger than the real distance of the receiver or facade point from the building’s facade surface. The default value for the minimum distance receiver - reflector is 1 m. This means that for all receivers and facade points being placed closer to building facade no reflection is considered in the calculation. 6 With a minimum distance of 0 m reflections will always be calculated, provided the building has reflective properties. When using the Object Snap (see chapter 9.3) to place receivers along facades the „Distance Point-Facade“ must be smaller than the minimum distance specified here in order to not calculate reflections (default distance: 0.05 m). The same applies regarding the distance of facade points with Building Evaluations (see chapter 5.4.1, section "Distance Receiver-Facade (m)", default value 0.05 m). All other reflectors located outside this minimum distance will cause reflections provided the other configuration settings and the respective object properties are adequate. Minimum Distance Receiver - Reflector, Interpolate to Here - in contrast to the maximum distance - a larger value than the minimum distance can be specified. For the intermediate region, the level values are interpolated linearly (from „none“ to „full“ reflection). A smaller value than the minimum distance receiver - reflector has no effect. CadnaA - Reference Manual Chapter 6 - Calculation 6.2.8 Reflection Tab 6 83 Examples\06_Configu • for a receiver at 0.05 m distance off the facade: ration\Reflection\min_dis tance_rcvr-reflector 6 close-up at the facade’s surface: minimum distance receiver - reflector: 1 m (default value), receiver at 0.05 meters off the facade (placed using object snap): In the region up to 1 m in front of the facade, the levels at receivers, along facades or on the grid are calculated without reflections (i.e. no ray is reflected by the facade). Outside this region (distance > 1 m) the facade reflection is taken into account. CadnaA - Reference Manual 84 6 Chapter 6 - Calculation 6.2.8 Reflection Tab • for the lines of equal noise level on the grid: 6 minimum distance receiver - reflector 1 m (default value), Interpolate to 1 m (default value): A level jump occurs at 1 m distance from the facade. minimum distance receiver - reflector 1 m (default value), Interpolate to 3 m: The level jump is smoothened by interpolation between 1 and 3 m distance off the facade. CadnaA - Reference Manual 6 85 Chapter 6 - Calculation 6.2.8 Reflection Tab When modeling of sound radiation from facades (see chapter 6.1 in the manual „Introduction to CadnaA“), the reflection by vertical area sources at the own building is usually taken into account by the directivity index K0 or D (see chapter 2.1.1 "Common Input Data", section "K0 without Ground"). In this case, it has to be prevented for considering reflected rays at the own facade in addition. The default value for the minimum distance source - reflector is 0.1 m. For a source located within that distance in front of the facade no reflection at the rear wall is calculated. When using the Object Snap (see chapter 9.3) to place vertical area sources a distance of 0.05 m is applied per default. In conjunction with the minimum distance source - reflector of 0.1 m this setting ensures that no reflection at the own building is taken into account. For all other sources that are laying outside this minimum distance, the building is reflective provided the other configuration settings are adequate. CadnaA - Reference Manual Minimum Distance Source - Reflector 6 86 6 Chapter 6 - Calculation 6.2.8 Reflection Tab Examples\06_Configu ration\Reflection\min_dis tance_source-reflector 6 minimum distance source - reflector 0.1 m: As the source with a distance of 0.05 m in front of the facade is located closer than the minimum distance, no reflection at the building occurs. minimum distance source - reflector 0 m: The calculation of reflections at the own house occurs always. In this case, it must be ensured the directivity index K0 resp. D of the source is set to 0 dB. Otherwise, the reflected component would be considered twice. CadnaA - Reference Manual Chapter 6 - Calculation 6.2.9 Industry Tab 6.2.9 6 87 Industry Tab Information on the calculation options for the following standards or guidelines for industrial sources can be found in the German version of the CadnaA-reference manual: VDI 2714/2720 DIN 18055 (1987) OEAL 28 (1987) The options on tab „Industry“ effect the following types of sources: • • • • 6 point, line, and area sources, vertical/horizontal (see chapter 2.1.1) tennis point of serve (see chapter 2.3) parking lot (see chapter 2.7) optimizable area source (see chapter 2.9) The subsequent table lists the main characteristics of the propagation models for industrial sources as treated in the next chapters explaining the configuration options. A special focus is put to the type of modeling being used for the various attenuating effects in sound propagation. Table „Propagation Models Industry“ A further table describes the properties of obstacles and special-objects in CadnaA with each propagation model. Table „Obstacles and Special-Objects“ Since for Nord 2000 an external DLL is performing the actual calculations no details are given in the subsequent tables for that standard (see chapter 6.2.9.3 "Nord 2000"). CadnaA - Reference Manual 88 6 Chapter 6 - Calculation 6.2.9 Industry Tab Propagation Models Industry No 6 Option or Propagation Effect Standard / Guideline ISO 9613 (1996) Nordic Prediction Method (1996) Nord 2000 (using DLL V20) 1 calculation using A-weighted levels yes yes (though not part of NPM originally) yes 2 spectral calculation yes (for octaves 63 Hz to 8000 Hz, extended in CadnaA down to 31.5 Hz) yes, see ISO 9613 yes (spectrum visible on protocol only) 3 geometrical attenuation (divergence) full sphere (4r2) see ISO 9613 full sphere (4r2) 4 attenuation by air absorption based on the air absorption coefficient accord. to ISO 9613-1 according to NPM, Annex B yes 5 handling of ground reflections not using image sources, but using an algorithm which includes the correction for ground absorption (see below) see ISO 9613 using complex ground impedance 6 handling of reflections at obstacles by image sources with no restriction to the maximum order of reflection, condition for reflection considers obstacle size compared to wavelength, sound power of the image source may include absorption coefficient/ reflection loss of the reflector see ISO 9613, but separate criteria for minimum length and height of reflector yes 7 attenuation due to ground effect (ground attenuation) 2 procedures: 1. general method (spectral): using ground factor G (0<=G<=1), „applicable only to ground which is approximately flat“ 2. alternative method (for A-weighted levels): generalized, not using ground factor G, „for ground surfaces of any shape“ see spectral method of ISO 9613, but with height correction when „significant screening occurs“ by complex ground impedance (based on entered G value) 8 attenuation due to screening (at objects) for single and double diffraction based on the path difference of the direct path across the obstacle, screened ray does by default not include a ground attenuation, screening effect considers wavelength REMARK: transm. through obstacles not considered by default, in CadnaA approximative approach using „acoustical Transparency“ effective height he is reduced by h for single screen, considers wave length, screened ray with ground attenuation by complex algorithm using Fresnel-zone 9 handling of lateral diffraction by considering two, lateral ray paths (via the vertical edges of an obstacle), lateral diffraction includes the ground attenuation by default for single screen only yes 10 handling of multiple obstacles in ray path unclear specification („may also be calculated approximately ... by choosing the two most effective barriers ...“) In CadnaA the so-called „ribbon band method“ is used for the calculation of the path difference with multiple screening objects. at multiple screens: „... find the two most effective single screens.“ (annex C) yes 11 attenuation due to screening (terrain) screening by terrain not treated explicitly, In CadnaA the algorithm for multiple screening objects is applied, however not considering any lateral diffraction. as with multiple screens (no lateral diffraction) yes 12 handling of meteorological effects (wind) 2 options (empirical correction Cmet): 1. based on the factor C0 2. additionally in CadnaA: derivation of C0 from a distribution of wind direction (which is not treated ISO 9613-2 completely) for „moderate downwind or slight temperature inversions“, no meteorol. correction for a specific meteo. situation (using wind dir. & speed, temp. gradient) 13 attenuation due to foliage based on length of the curved ray path (arc of a circle) passing through the foliage (with height h) assuming a radius of 5 km based on transmission path length (with h) not available 14 attenuation due to built-up areas based on length of the curved ray path (arc of a circle) passing through the foliage (with height h) assuming a radius of 5 km acc. to NPM, Annex D (internal scattering Li) not available CadnaA - Reference Manual 6 89 Chapter 6 - Calculation 6.2.9 Industry Tab Standard / Guideline Ljud fran vindkraftverk BS 5228 Harmonoise (using DLL 2.020) No Concawe NMPB 2008 CNOSSOS-EU yes yes yes yes yes yes 1 yes (for A-weighted sum level only) yes (though not part of original paper) yes, see ISO 9613 yes, see ISO 9613 yes (1/3 octaves, 100 to 5000 Hz) yes (for octaves 63 Hz to 8000 Hz, + 31.5 Hz 2 half sphere (2r2) divergence mixed with ground attenuation full sphere (4r2) full sphere (4r2) point source propagation (4r2) point source propagation (4r2) 3 using 0.005 dB/m not available complex transfer function (via DLL) based on air absorption coeff. (table) acc. ISO 9613-1 (for 15°C, 70%) yes (acc. to ISO 9613-1) 4 see ISO 9613 for two categories (soft/hard) see above specific algorithm, not by image sources algorithmic, not by image sources algorithmic incl. ground absorption (see below) 5 not available see ISO 9613 see above see ISO 9613 yes yes 6 two ground categories (over land = soft, over water = hard) ground attenuation for two categories (soft/hard) and for mixed ground see above spectral model only (63 to 4000 Hz, in CadnaA extended to 32 and 8000 Hz) spectral model (for favorable: ISO 96132, for homogeneous specific) for 2 prop. conditions using ground factor G: - homogeneous cond. - favorable conditions 7 not available see ISO 9613 see above using the Fresnelnumber based on the path length difference based on path length difference single & double diffraction, includes ground effect on both sides of obstacle, with mirror source and receiver 8 not available not available see above not available not expressively considered by 2 rays at vertical edges, including ground effect 9 not available not available see above so-called „ribbon band method“ is used to obtain path length difference via path length difference via path length difference (convex hull) 10 not available see ISO 9613 see above see ISO 9613 as with multiple screens see ISO 9613-2 11 not available not available for a specific meteorological situation (using stability class, wind dir. & speed) for a specific meteorological situation (using stability class, wind dir. & speed) using occurrences of homogeneous and favorable propagation conditions using occurrences of homogeneous and favorable prop. conditions, energetic addition 12 not available not available not available not available not available not available 13 not available not available not available not available not available not available 14 CadnaA - Reference Manual 6 90 6 Chapter 6 - Calculation 6.2.9 Industry Tab Obstacles & Special Objects 6 No Object Type/ Option Standard / Guideline ISO 9613 (1996) Nordic Pred. M. (1996) 1 building single & multiple diffraction for edges parallel to the ground (shortest path difference), lateral diffraction by vertical edges, no reflection or input of absorption coeff./reflection loss, not normative: input of transmission coefficient (%), no acoustical transparency by default diffract. at upper edge, no lateral diffr. (in NPM for single edge only), no acoust. transp. yes 2 cylinder single and multiple diffraction via the cylinder based on the shortest path difference, lateral diffraction via the perimeter, no reflection or by input of absorption coefficient/reflection loss, reflection up to 1st order (implementation in CadnaA differs from ISO 9613-2 as incomplete there) diffract. at upper edge, lateral diffr. as for a single edge yes 3 barrier single and multiple diffraction for edges parallel to the ground based on the shortest path difference, lateral diffraction via the vertical edges, no reflection or by input of absorption coefficient/reflection loss diffract. at upper edge, lateral diffr. only at the first vertical edge yes 4 floating barrier no diffraction via the lower edge (screening edge without diffraction), otherwise see barrier see ISO 9613 yes 5 barrier with cantilever cantilever is totally absorbing (no reflection), calculation of the path length difference valid for receivers/grid points outside and below the cantilever, otherwise see barrier cantilever not available (not compatible with „effective height“ concept) yes 6 bridge plate diffraction calculation for horizontal plate only (inclined plate approximated to horizontal plate), screening for sources below/above the bridge plate (diffraction up-/downwards), no reflection-induced level increase below the bridge plate (as ground is not modeled by mirror sources) see ISO 9613 no effect 7 embankment acts as a double barrier, diffraction for direct path (without lateral diffraction), no absorptive/reflective properties REMARK: The embankment‘s top edge is not considered in the triangulation! see ISO 9613 yes 8 ground absorption area just relevant with the frequency dependent ground attenuation: procedure uses three regions (source, receiver, and middle region), empirical attenuation based on source and receiver height and distance (accord. to Kragh) see ISO 9613 no effect 9 built-up area/ foliage without screening calculation, attenuation based on the length of the curved ray path (arc of a circle) passing through the built-up area/foliage assuming a radius of 5 km no built-up area in NPM (in CadnaA as in ISO 9613), foliage: based on path length using heff no effect 10 3D-reflector screening using shortest path length difference, two lateral paths, diffraction can be suppressed for up to 32 edges, no reflection or input of absorption coeff./reflection loss, reflection up to 1st order, no summation of diffraction components via multiple edges, no multiple diffraction no screening effect (not compatible with „effective height“ concept) no effect 11 self screening not relevant not relevant not relevant 12 additional width/ parapet L/R not relevant not relevant not relevant Nord 2000 (V20) CadnaA - Reference Manual 6 91 Chapter 6 - Calculation 6.2.9 Industry Tab Standard / Guideline Ljud vindkra. BS 5228 Harmonoise Concawe No NMPB 2008 CNOSSOS-EU no effect diffr. at 1st edge parallel to the ground only, no lateral diffr., no acoust. transpar. see ISO 9613, but no acoustical transparency, reflection based on airflow resistivity see ISO 9613 see ISO 9613 see ISO 9613, but for homogeneous & favorable conditions 1 no effect see ISO 9613 see ISO 9613 see ISO 9613 see ISO 9613 for homogeneous & favorable conditions 2 no effect diffr. at 1st edge parallel to the ground only, no lateral diffr. see ISO 9613, reflection based on airflow resistivity see ISO 9613 see ISO 9613 see ISO 9613, but for homog. & favorable cond. 3 no effect see ISO 9613 yes see ISO 9613 see ISO 9613 see ISO 9613 4 no effect see ISO 9613 yes see ISO 9613 not available see ISO 9613 5 no effect see ISO 9613 no effect see ISO 9613 see ISO 9613 see ISO 9613 6 no effect see ISO 9613 yes see ISO 9613 see ISO 9613 see ISO 9613 7 no effect see ISO 9613, also with weighted source data (based on the frequency specified) based on airflow resistivity (in CadnaA: classes of ground factor G) see ISO 9613, also with weighted source data (using specified freq.) using ground factor G (for favorable and homogeneous) yes, using ground factor G (for favorable and homogeneous) 8 no effect no effect no effect no effect not available no effect 9 no effect see ISO 9613 no effect see ISO 9613 not available see ISO 9613 10 not relevant not relevant not relevant not relevant see ISO 9613 see ISO 9613 11 not relevant not relevant not relevant not relevant see ISO 9613 see ISO 9613 12 CadnaA - Reference Manual 6 92 6 Chapter 6 - Calculation 6.2.9 Industry Tab 6 CadnaA - Reference Manual 6 93 Chapter 6 - Calculation 6.2.9.1 ISO 9613 6.2.9.1 ISO 9613 6 Three options for lateral diffraction are available for selection: • none: No lateral diffraction considered, just the direct path sourcereceiver is evaluated. • only one object: Lateral diffraction is not calculated if more than one object intersects the line connecting the source to the receiver point. • some objects: The two shortest possible convex rays around the arrangement of objects are determined and used for the calculation of the lateral diffraction. This setting defines the distance between source and receiver for which lateral diffraction is taken into account. The default value is 1000 m. The limit of the screening attenuation Dz for single and multiple diffraction accord. to ISO 9613-2, section 7.4, is in CadnaA not applied to the two lateral paths, but to the direct path only. Otherwise, the screening attenuation for single or multiple diffraction resp. would get limited to 20-10 lg (3)=15.2 dB or 25-10 lg (3)=20.2 dB, respectively (see also section "Barrier Attenuation" below). CadnaA - Reference Manual Lateral Diffraction if Distance smaller (m) 94 6 Lateral Diffraction with multiple Edges or Objects Chapter 6 - Calculation 6.2.9.1 ISO 9613 With CadnaA release 4.3 the strategy when calculating lateral diffraction around objects with more than one diffracting edge or multiple objects has been changed. Now, the parameter e (distance between first and last diffracting edge) is considered when calculating C3 according equation 15 of ISO 9613-2 /8/. In previous releases, the constant value C3=1 was used instead. 6 The change refers to the calculation of the lateral diffraction only. For the direct path, however, the parameter e has always been and is still taken into account when calculating C3. By a local text block OPT_OLD_CALC and the text SBEUG_e0_X141=1, the former value C3=1 can be set. If this text block does not exist or the value is zero (SBEUG_e0_X141=0), the new strategy is used. Level Increase due to Lateral Diffraction By selecting the option „none“ (i.e. no lateral diffraction, see above) it can be easily checked that the screening effect for the direct path does not change, regardless of whether the text block is set or not. With calculations accord. to ISO 9613-2 the receiver level including an obstacle (e.g a building) and terrain can be higher, than just with terrain (e.g. with the buildings deactivated). When calculating the screening effect by terrain no lateral diffraction is calculated. With an additional obstacle, however, the effect by lateral diffraction by that obstacle is added. This could cause an increase of the local receiver level. CadnaA - Reference Manual 6 95 Chapter 6 - Calculation 6.2.9.1 ISO 9613 Therefore, in case the screening effect by an obstacle is smaller than without (i.e. with terrain only) the screening effect ignoring the obstacle is considered by CadnaA. This strategy can be deactivated using the local text block OPT_OLD_CALC with the text VERSION_X=115. 6 Example Examples\06_Configuration\ISO 9613 actual default setting for lateral diffraction accord. to ISO: Level with obstacle (e.g. with building) must be lower than without. (no local text block OPT_OLD_CALC with text VERSION_X=115) file ISO - lateral diffraction & terrain - 1.cna former effect due to lateral diffraction: higher receiver level with building, than without (with local text block OPT_OLD_CALC with text VERSION_X=115) file ISO - lateral diffraction & terrain - 2.cna CadnaA - Reference Manual 96 6 Chapter 6 - Calculation 6.2.9.1 ISO 9613 Screening & Ground Attenuation The following options are available to account for the ground attenuation in conjunction with the calculation of the screening effect. Exclude Ground Attenuation over Barrier With this setting the ground attenuation is excluded from the total attenuation of screened rays. This is the default setting in CadnaA. Explanatory Remarks: ISO 9613-2, equation (12) states (for top edge): Abar Dz Agr 0 dB In conjunction with equation (4): A Adiv Aatm Agr Abar Amisc 6 it results that for screened rays no ground attenuation Agr is considered: A Adiv Aatm Agr Dz Agr Amisc Adiv Aatm Dz Amisc This setting is, therefore, in line with the specifications in ISO 9613-2. Include Ground Attenuation over Barrier The ground attenuation is included in the total attenuation of screened rays. The mean height above ground of the ray between source and receiver when passing over the barrier is considered in the calculation. Explanatory Remarks: With this option the equation (13) of ISO 9613-2 is applied: Abar Dz 0 dB This equation holds as well for the two lateral paths. For the total attenuation it results according to equation (4): A Adiv Aatm Agr Dz Amisc In this case, the ground attenuation Agr is considered also for the diffracted rays. 10 m-Criterion When a source is higher than 10 m above ground and at least one screening edge is higher than 10 m above ground, accord. to ISO 9613-2, note 15, equation (13) is used to calculate the attenuation by a barrier Abar (with Abar = Dz > 0 dB). CadnaA - Reference Manual 6 97 Chapter 6 - Calculation 6.2.9.1 ISO 9613 For the barrier attenuation the following options are available from the list box: • • • • Barrier Attenuation Dz without limit Dz with limit (20/25) De,o with limit Dz with limit (20/20) The limitation refers in any case to the direct path only. The barrier attenuation resulting for the two lateral paths is not limited in CadnaA (see also section "Lateral Diffraction" above). 6 With this option activated the barrier attenuation Dz increases with increasing path difference z without any limitation (accord. to equation (14) in ISO 9613-2). Dz without limit According to ISO 9613-2 the barrier attenuation Dz is limited to 20 dB for a single, and to 25 dB for a two or more screening edges. Therefore, this is the default setting. Dz with limit 20/25 The option „De,o with limit“ refers to the former German guidelines VDI 2714 /38/ and VDI 2720-1 /40/. This setting is not relevant for ISOcalculations, but has to be kept to ensure downward compatibility with old projects. De,o with limit According the new Austrian edition of ISO 9613-2 (see ÖNORM ISO 96132:2008-01) the barrier attenuation Dz of two or more screening edges is for Austria limited to 20 dB, thus deviating from the original document. Dz with limit 20/20 CadnaA - Reference Manual 98 6 No Subtraction of negative Ground Attenuation Chapter 6 - Calculation 6.2.9.1 ISO 9613 With this option activated, a negative ground attenuation (e.g. with reflecting ground) will be ignored when calculating Abar. Consequently, the total attenuation A considers the ground attenuation Agr for the screened ray. So, with reflecting ground, equation (12) of ISO 9613-2 is not applied, but equation (13). By default, this option is deactivated as ISO 9613-2 does not specify this additional condition (Agr > 0 dB). Explanatory Remarks: 6 Equation (12) in ISO 9613-2 is: Abar Dz Agr 0 dB For low frequencies and absorbing ground or generally with reflecting ground the ground attenuation Agr becomes negative. In this case, the attenuation due to a barrier Abar would be increased since the ground attenuation Agr would be added to the barrier attenuation Dz. With this option activated, it will be used for the screened ray instead: Abar Dz 0 dB Thus, when calculation the total attenuation A the ground attenuation Agr is considered according to: A Adiv Aatm Agr Dz Amisc No negative path difference With activated option no barrier attenuation is calculated when the ray from the source to the receiver is above the upper edge of the barrier. By default, this option is deactivated Explanatory Remarks: The barrier attenuation Dz according to equation (14) in ISO 9613-2 produces a distinct screening effect even when the ray passes slightly above the barrier’s top edge. ISO 9613-2, section 7.4, states that the path difference z receives a negative sign in this case. By this approach, the calculation model according to ISO 9613-2 accounts for the theoretical fact from diffraction theory that the screening effect does not vanish instantly in case the ray passes just a little above the screening edge. If this option is activated, Abar is set to zero at a negative z. CadnaA - Reference Manual Chapter 6 - Calculation 6.2.9.1 ISO 9613 In ISO 9613-2, two methods are mentioned to calculate the ground attenuation Agr: 1. „general method“: method in frequency bands according to section 7.3.1 with the ground factor G as parameter, 2. „alternative method“: method for A-weighted levels according to section 7.3.2 not applying the ground factor G. As in projects the sound emission of sources can either be given in spectral form or as A-weighted levels, several possibilities exist to calculate the ground attenuation. In CadnaA four calculation options are available: Designation Procedure none no ground attenuation at all However, the ground reflection is still accounted for by using equation (11) of ISO 9613-2. not spectral method 7.3.2 is used in all cases For spectral sources the same value of Agr results for all octaves. spectral, spectral sources only The method 7.3.1 is used for all spectral sources, in all other cases the method 7.3.2 is used. This corresponds in CadnaA, version 3.3 and former, with the option „Ground Attenuation spectral“ being activated. spectral, all sources Method 7.3.1 is used in all cases, for non-spectral sources the corresponding octave band is used. For A-level sources the value for Agr at the specified frequency is used. WEA interim (-3 dB) A fixed value for Agr of -3 dB is used with A-weighted or for all octaves with spectral calculations (according to the German LAI interim method for wind turbine noise assessments /123/). The directivity index D_omega is 0 dB in both cases. The default setting in CadnaA is the option „spectral, all sources“ as this is the „general method of calculation“ according to ISO 9613-2. CadnaA - Reference Manual 6 99 Ground Attenuation 6 100 6 Non-spectral Ground Attenuation Chapter 6 - Calculation 6.2.9.1 ISO 9613 With non-spectral ground attenuation selected ("alternative method"), the mean height h_m is calculated in CadnaA, starting from release 4.1, based on the 3D distance (distance d in Figure 3, ISO 9613-2 /8/). This change, now corresponding strictly with the standard’s specification (d in equation (10) denotes the 3D distance, see Figure 3), causes at receiver points above and below the source the ratio h_m/d to become very small, resulting in Agr = 4.8 dB. Prior to CadnaA release 4.1 of the horizontal distance (2D distance) was used instead to prevent this effect. This implementation, however, was not strictly in line with the standard’s specification (see illustrations). 6 Examples\06_Configuration\ISO 9613 vertical level distribution, Agr from 3D distance, w/o textblock or with textblock OPT_OLD_CALC with the text ISO_HM_X137=0 (file ISO - alt. proc. - Agr from 3D distance.cna) vertical level distribution, Agr from 2D distance, with textblock OPT_OLD_CALC with the text ISO_HM_X137=1 (file ISO - alt. proc. - Agr from 2D distance.cna) CadnaA - Reference Manual Chapter 6 - Calculation 6.2.9.1 ISO 9613 6 101 The previously used procedure can be toggled using the local text block OPT_OLD_CALC with the text ISO_HM_X137 = 1. The procedure applied in CadnaA to evaluate the mean height h_m in the non-spectral ground attenuation model („alternative method“ in chapter 7.3.2 of ISO 9613-2 /8/) is as follows: • The line of sight source-receiver (ray path) is not blocked by obstacles or terrain: CadnaA evaluates the area below the ray path and the 3D-distance source-receiver (as shown in Figure 3, ISO 9613-2). The internal calculation procedure evaluates distances and heights step-by-step for each point of terrain or obstacle/s in the ray path. • The line of sight is blocked by obstacles or terrain: This case is not treated in ISO 9613-2 explicitly. As CadnaA applies the "rubber-band-method" to calculate the screening effect by multiple objects, a similar rule is applied here: The area below the diffracted path source-receiver minus the area of obstacles or terrain in path is used to calculate the area F, giving in conjunction with the 3D distance the mean height h_m. CadnaA - Reference Manual Mean Height with nonspectral Ground Attenuation 6 102 6 Chapter 6 - Calculation 6.2.9.1 ISO 9613 The latter case is illustrated in more detail by a simple example: Assume a hill in line of sight being a symmetrical triangle in cross-section. The area relevant for h_m is the area below the red line (diffracted ray path) minus the green hatched area (hill area). 6 spectral Ground Attenuation When calculating the ground absorption in frequency bands („general method“ according to ISO 9613-2) the global ground absorption for areas not covered by the object "Ground Absorption" (see chapter 3.4) is defined via the „Ground Absorption“ tab (see chapter 6.2.7). A default value of G=1 is used (porous ground). In contrast to the „alternative method“ the 2D distance is used by the „general method“ to calculate the ground attenuation (dp). CadnaA - Reference Manual 6 103 Chapter 6 - Calculation 6.2.9.1 ISO 9613 When this option is active, any obstacle (e.g. buildings, foliage, barriers etc.) located within area sources (including parking lots and optimizable sources) provide no screening for any sub-source of that area source. Obstacles within Area Source do not Shield Example 6 Area source with 2 buildings inside, option activated: sources with free propagation (with all rays displayed) With this option activated the result levels are calculated as if the obstacles were not present (i.e. no screening effect). Area source with 2 buildings inside, option deactivated: sub-sources behind the buildings are screened, sub-sources in front of buildings with free propagation (screened rays in RED) With this option deactivated lower levels result at the receiver points due to the screening effect of the obstacles inside. Nevertheless, for all other sources (i.e. sources outside of the are source’s border) the obstacles inside cause always screening. The decision whether an obstacle is located inside of an area source is based on the location of the obstacle’s first polygon point. CadnaA - Reference Manual 104 6 Sources in Building/ Cylinder do not shield Chapter 6 - Calculation 6.2.9.1 ISO 9613 By default, a screening effect results for sources inside buildings and cylinders as the outer walls act as barriers. In this case, prior to the calculation, a message will be displayed (dialog Consistency Check) which enables to proceed with the operation (button „Continue“). This procedure is due to the fact that buildings and cylinders are treated as open boxes within the calculation of propagation (despite they are displayed as „closed“ objects (i.e. with roof) on the 3D-Special View). 6 With this option activated, sources located inside of the geometrical borders of buildings or cylinders are not screened as if the obstacle were not present. For sources outside, those obstacles are always screening and - if any reflecting. This option enables to model e.g. sound radiating chimneys by using point or line sources located inside the cylinder. In this case, the directivity pattern of the chimney - whether entered or selected from the default directivities - will not distorted by the cylinder’s screening edge. Example see manual „Introduction to CadnaA“, chapter 6.3 Directivity Barrier Coefficient The barrier coefficients C1, C2 and C3 according to ISO 9613-2 can be edited. This option enables to adapt the barrier equation to special applications (see /8/, section 7.4). In ISO 9613-2 the coefficient C1 is not expressed explicitly. The first constant („3“) in equation (14) corresponds with C1. The default values are: C1 = 3 dB; C2 = 20 dB; C3 = 0 dB. The input C3 = 0 dB causes this value to be calculated according to ISO 9613-2, equations (15), (16) and (17) for single and double barriers automatically. CadnaA - Reference Manual 6 105 Chapter 6 - Calculation 6.2.9.1 ISO 9613 The air attenuation is calculated based on the temperature and the relative humidity according to ISO 9613-1. Intermediate frequency values result from linear interpolation. The temperature specified serves also as the ambient temperature when calculating the exhaust stack’s directivity. Temperature / rel. Humidity Regarding the calculation of the air attenuation for octave 31.5 Hz see section "Additional Information" at the end of this chapter. Explanatory Remarks: CADNAA calculates the air attenuation according to equations (3), (4) and (5) of section 6.2 ISO 9613-1/8/. This also holds for intermediate input values and for input values outside the range of list boxes. By default, the above-mentioned equations just apply to the air attenuation of pure tones. Section 7 of ISO 9613-1 provides information on the accuracy of the attenuation coefficients for certain ranges of input values (for final accuracies of +/- 10%, +/- 20%, +/- 50%). Section 8 of ISO 9613-1 provides information on the accuracy of the air attenuation when transferring the pure-tone method to band-level attenuation (for third-octaves or octaves). Refer to this information - if required - when using input data outside the range of tabulated attenuation coefficients of ISO 9613-1: - frequency from 50 Hz to 10 kHz, - temperature from -20 ° C to +50 ° C, - relative humidity from 10% to 100%, and - air pressure of 101,325 kPa (one atmosphere). For calculations according to ISO 9613-2 a user-defined air attenuation spectrum can be referenced. Enter a spectrum in the local library "Absorptions" with the ID "SYS_ATM_ABSORB". The values have to be specified in dB/ km. Missing octave band data will be considered as 0 dB/km. Local Absorption Spectrum SYS_ATM_ABSORB CadnaA - Reference Manual 6 User-defined Air Attenuation 106 6 Chapter 6 - Calculation 6.2.9.1 ISO 9613 Meteorology For calculations according to ISO 9613 the following options are available: none No correction is applied. The resulting equivalent continuous sound pressure level is calculated applying equation (3) for the meteorological situation as described in ISO 9613-2, section 5 (downwind). Cmet, C0 constant This option calculates the long-term average A-weighted sound pressure level according to ISO 9613-2, equation (6). This requires to specify the value of C0 for the periods Day/Evening/Night where the meteorological correction Cmet is calculated from according to ISO 9613-2, section 8, equations (21) and (22) resp. 6 The factor C0 may be estimated from an elementary analysis of the local meteorological statistics or may be established by the local authorities. Cmet, C0 from wind statistics With this option two methods for calculation of C0 from wind statistics are available on the subsequent dialog Wind Statistics: method LfU Bayern: The approach used by the LfU-Bayern (Bavarian Environmental Agency) to calculate C0 is: Kq Kg K T m Tq Tg C 0 10 lg m 10 10 10 10 10 10 100 100 100 where Tm Km Tq Kq Tg Kg percentage of annual downwind situations and calmness (inversions) in % level difference to the downwind situation in dB percentage of annual cross-wind situations in % level difference of cross-wind situations to the downwind situation in dB percentage of annual upwind situations in % level difference of upwind situations to the downwind situation in dB The percentages T for downwind, crosswind, and upwind result from the wind frequencies in the following sectors: - down: +/-45° in direction of propagation (=90° sector) and calmness, - cross: 45° to 135° and 225° to 315° in direction of propagation, - up: +-45° opposite to the direction of propagation (=90° sector). Example for method „LfU Bayern“ see chapter 6.6.2 "Correction based on Wind Statistics" in the manual „Introduction to CadnaA“. CadnaA - Reference Manual 6 107 Chapter 6 - Calculation 6.2.9.1 ISO 9613 method LUA NRW: The approach used by the LUA NRW (Environmental Agency of North-Rhine-Westphalia) to calculate C0 is: Lz 5 5 * cos 45 sin where wind direction referring to downwind And c h * 10 lg100.1*L 6 with the frequency h() in wind sector 1 to 2: h h1 h 2 h1* where 1 2 1 angle 0-360 degrees The value C0 results by summation from: c C0 10 lg in dB 100 This means that at large distances and on a long-term annual average basis the attenuation with cross winds is 1.5 dB and with upwind 10 dB. The frequency of calmness is evenly distributed among the 12 wind sectors. The values of C0 for the locations investigated by LUA NRW range from 1 dB to 3.9 dB. relevant for Germany only! According to the „Vorläufige Berechnungsmethode für den Umgebungslärm durch Industrie und Gewerbe (VBUI)“ /116/ the following values for C0 are to used when calculating Cmet: C0,Day = 2 dB; C0,Evening = 1 dB; C0,Night = 0 dB CadnaA - Reference Manual VBUI 108 6 Concawe Chapter 6 - Calculation 6.2.9.1 ISO 9613 With former releases of CadnaA an additional option enabling to apply the meteorological correction K4 according to CONCAWE /1/ was offered. As the entire CONCAWE model is now available in CadnaA this option has been removed. However, it can be reactivated by adding the following lines to the MAIN-section of the file CADNAA.INI: [Main] IsoCmetConcawe=1 6 In order to locate the INI-file use the command Open INI-file on the Options menu (see Chapter 2 - Installation, section "INI-files", in the manual „Introduction to CadnaA“). When this option is selected from the „Industry“ tab the correction term Cmet in the ISO 9613-2 calculation is replaced by K4 from CONCAWE. Please consider that the ISO model by default addresses a moderate downwind situation. In ISO 9613-2, the term Cmet corrects for a longterm average level with a different meteorological situation than the default situation. As the meteorological correction K4 according to CONCAWE itself represents a distinct meteorological situation, it is questionable what the term K4 in conjunction with the downwind approach is focusing at. This option was formerly introduced into CadnaA based in user requests. CadnaA - Reference Manual 6 109 Chapter 6 - Calculation 6.2.9.1 ISO 9613 Additional Information By default, calculations according to ISO-9613-2 just cover the frequency range for octaves from 63 to 8000 Hz. Based on user requests, CadnaA offers the octave band at 31.5 Hz in addition. Calculations for octave 31.5 Hz For predictions in the 31.5 Hz octave band the following rules apply: • atmospheric absorption Aatm: The standard ISO 9613-1 /8/ provides equations which are used to calculate the air absorption in the 31.5 Hz octave band. • frequency dependent ground attenuation Aground: The same equations as for the octave band at 63 Hz are used. • barrier attenuation (Dz): The equation (14) as for all other octave bands is used, however, with the wavelength at 31.5 Hz. • reflection criterion: The equation (19) as for all other octave bands is used, however, with the wavelength at 31.5 Hz. • objects „Foliage“ and „Housing Attenuation“: The same equations as for the octave band at 63 Hz are used. CadnaA - Reference Manual 6 110 6 Chapter 6 - Calculation 6.2.9.1 ISO 9613 6 CadnaA - Reference Manual 6 111 Chapter 6 - Calculation 6.2.9.2 Nordic Prediction Method (1996) 6.2.9.2 Nordic Prediction Method (1996) 6 Three options for lateral diffraction are available for selection: • none: no lateral diffraction considered, just the direct path is evaluated. • only one object: This option has in conjunction with NPM the same effect as „none“ and should, therefore, NOT be used. • some objects: In conjunction with NPM this option causes the two shortest possible convex rays around the first diffracting edge to be determined and used in the calculation. Due to restrictions in Nordic Prediction Method, lateral diffraction occurs just at the first diffracting edge. Consequently, a further barrier behind a first barrier in ray direction will not cause a lateral diffraction. Also at buildings (being multi-point objects) no lateral diffraction occurs. This setting defines the distance between source and receiver for which lateral diffraction is taken into account. The default value is 1000 m. CadnaA - Reference Manual Lateral Diffraction if Distance smaller (m) 112 6 Obstacles within Area Source do not Shield Chapter 6 - Calculation 6.2.9.2 Nordic Prediction Method (1996) When this option is active, any obstacle (e.g. buildings, foliage, barriers etc.) located within area sources (including parking lots and optimizable sources) provide no screening for any sub-source of that area source. Example 6 Area source with 2 buildings inside, option activated: sources with free propagation (with all rays displayed) With this option activated the result levels are calculated as if the obstacles were not present (i.e. no screening effect). Area source with 2 buildings inside, option deactivated: sub-sources behind the buildings are screened, sub-sources in front of buildings with free propagation (screened rays in RED) With this option deactivated lower levels result at the receiver points due to the screening effect of the obstacles inside. Nevertheless, for all other sources (i.e. sources outside of the are source’s border) the obstacles inside cause always screening. CadnaA - Reference Manual 6 113 Chapter 6 - Calculation 6.2.9.2 Nordic Prediction Method (1996) The air attenuation is calculated based on the temperature and relative humidity as given in annex B of the paper /71/. Intermediate frequency values result from linear interpolation. The temperature specified serves also as the ambient temperature when calculating the exhaust stack’s directivity. Temperature / rel. Humidity The entered wind speed will be used in the calculation of the directivity of chimneys (see chapter 2.2.1 "Sound Radiation from Chimneys or Stacks"). Wind Speed for Directivity (m/s) 6 CadnaA - Reference Manual 114 6 Chapter 6 - Calculation 6.2.9.2 Nordic Prediction Method (1996) Additional Information Diffraction Model The screening model for industrial noise of Nordic Prediction Method /71/ covers the diffraction effect with just a single screening edge. With two or more edges, there is no specification on how to apply the concept using the additional height h to multiple screening edges. In section 4.5.1 of /71/ it says: „The general principle in calculating the screening correction, Ls, is to identify all screening obstacles between source and immission point. ... The calculation procedure depends on the number of screens present. Usually only one screen is taken into account. Ls is then calculated according to section 4.5.4. If more than one screen are present, the procedure in Appendix C [„Screening by more than one screen“, see section „Multiple Screens“ below] should be applied.“ 6 Section 4.5.4 describes the procedure for a single screening edge. The additional height h above the direct path is calculated from the horizontal distance (2D-distance) from source and receiver, respectively. The remaining height to the barrier’s top edge is the so-called „effective“ height he which is used to evaluate the path difference. Lateral Diffraction For the lateral path it is stated on page 37: „When a building is represented by a single screen, r and l [path differences] are calculated for the edges yielding the highest values.“ This expresses that the diffraction model cannot handle several edges neither for the direct (vertical), nor for the lateral paths (horizontal). In figure 4.5.7 (sectional view) just the first edge of the building is addressed (as if it would be a flat barrier). Multiple Screens Annex C describes for an arrangement of multiple screens with respect to the direct path on how to evaluate „the two most effective single screens“ („effective“ with respect to the ray’s elevation angle is meant). However, nothing is said on how to account for lateral diffraction in this case. In note 1 it says: „It must be emphasized that the recommended procedure is of rather speculative nature ...“ CadnaA - Reference Manual 6 115 Chapter 6 - Calculation 6.2.9.2 Nordic Prediction Method (1996) As annex C does not address the application of this scheme to the lateral paths in an arrangement with multiple screening objects, CadnaA applies the lateral path calculation to the first screening edge only. Applying the „ribbon band method“ for multiple objects (as with ISO 9613-2) would cause a level difference compared to the procedure used for a single screening edge only. Comparing lateral diffraction using ISO 9613-2 and NPM. Object ISO 9613-2 Nordic Prediction Model (1996) lateral diffraction occurring at 1st and 2nd vertical edge no lateral diffraction due to the restrictions of the diffraction model lateral diffraction occurring at 1st and 2nd barrier lateral diffraction occurring at 1st barrier, but not at 2nd barrier building (height 100 m), option „some objects“ for lateral diffraction selected two barriers behind each other (height 100 m each), option „some objects“ for lateral diffraction selected CadnaA - Reference Manual Example 6 116 6 Attenuation due to Vegetation Chapter 6 - Calculation 6.2.9.2 Nordic Prediction Method (1996) The Nordic Prediction Method distinguishes between a single and multiple vegetation areas in the ray path. For a single vegetation area, the attenuation depends on the length of the ray passing through the foliage (considering the additional height h above the direct path). For multiple vegetation areas, the attenuation depends on the number of vegetation areas, with a maximum of four. In CadnaA, the attenuation Lv for a single and multiple vegetation areas is always calculated based transmission path length dv (considering the additional height h) and not on the number of groups of vegetation: 6 Lv nV v with nV dv 4 50 where dv: transmission path length (m) v: attenuation coefficient accord. to table 4.6.1 of /71/ Attenuation due to Internal Scattering The object „Built-Up Area“ in CadnaA applies the algorithm for so-called „internal scattering Li“ given in Nordic Prediction Method, annex D. The attenuation Li“ calculates from: Li i d i 10 dB with di: transmission path length (m) iattenuation coefficient accord. to table D of /71/ CadnaA - Reference Manual Chapter 6 - Calculation 6.2.9.3 Nord 2000 6.2.9.3 6 117 Nord 2000 6 The implementation of "Nord 2000 Industry" in CadnaA makes use of the dynamic link library Nord2000.dll distributed by the Norwegian Public Roads Administration (http://www.vegvesen.no) and developed by the Scandinavian research organization SINTEF (http://www.sintef.no). This DLL is part of the CadnaA installation procedure. Since DataKustik is not the developer, we can neither comment, nor explain results obtained using this DLL. In case of inquiries please contact NPRA or SINTEF. Since there is no 64-bit DLL available, Nord 2000 cannot be used with CadnaA 64-bit version. Furthermore, the 32-bit DLL developed by SINTEF has no multi-threading capabilities. Consequently, just a single core will be used slowing down the calculation with complex sceneries. CadnaA - Reference Manual General Information 118 6 Nord 2000 DLLVersion Chapter 6 - Calculation 6.2.9.3 Nord 2000 On the list box „Version“ the available versions of the Nord2000.dll are listed. The most recent is selected by default. After the first calculation using Nord 2000 (Industry) the DLL-version will be displayed. Obstacles within Area Source do not shield When this option is active, any obstacle (e.g. buildings, foliage, barriers etc.) located within area sources (including parking lots and optimizable sources) provide no screening for any sub-source of that area source. for an example see chapter 6.2.9.5 "BS 5228" 6 Sources in Building/ Cylinder do not shield By default, a screening effect results for sources inside buildings and cylinders as the outer walls act as barriers. In this case, prior to the calculation, a message will be displayed (dialog Consistency Check) which enables to proceed with the operation (button „Continue“). This procedure is due to the fact that buildings and cylinders are treated as open boxes within the calculation of propagation (despite they are displayed as „closed“ objects, i.e. with roof, on the 3D-Special View). With this option activated, sources located inside of the geometrical borders of buildings or cylinders are not screened as if the obstacle were not present. For sources outside, those obstacles are always screening and - if any - reflecting. This option enables to model e.g. sound radiating chimneys by using point or line sources located inside the cylinder. In this case, the directivity pattern of the chimney - whether entered or selected from the default directivities - will not distorted by the cylinder’s screening edge. Example see manual „Introduction to CadnaA“, chapter 6.3 Directivity CadnaA - Reference Manual 6 119 Chapter 6 - Calculation 6.2.9.3 Nord 2000 The Nord 2000 model applies a specific input data set for the meteorological correction using the following input data: Meteorology The air attenuation is calculated based on the temperature and relative humidity. Intermediate frequency values result from linear interpolation. The temperature specified serves also as the ambient temperature when calculating the exhaust stack’s directivity. Temperature / rel. Humidity The height at which the wind speed was measured (default value: 10 m). Height of Wind (m) The roughness length characterizes the turbulence conditions of the atmospheric boundary layer. This parameter is used in the vertical wind profile equations predicting the horizontal mean wind speed near the ground (default value: 0.025 m). Roughness length (m) 6 For information, some typical roughness lengths are listed in the table below referring to the CORINE cadastre: z0 in m Classes according to the CORINE cadastre 0.01 Beaches, dunes, sands (331); Water bodies (512) 0.02 Dump sites (132); Pastures (231); Natural grasslands (321); Sparsely vegetated areas (333); Salt marshes (421); Intertidal flats (423); Water courses (511); Estuaries (522) 0.05 Mineral extraction sites (131); Sport and leisure facilities (142); Non-irrigated arable land (211); Glaciers and perpetual snow (335); Coastal lagoons (521) 0.10 Airports (124); Inland marshes (411); Peat bogs (412); Sea and ocean (523) 0.20 Road and rail networks and associated land (122); Green urban areas (141); Vineyards (221); Complex cultivation patterns (242); Land principally occupied by agriculture, with significant areas of natural vegetation (243); Moors and heathland (322); Bare rocks (332) 0.50 Port areas (123); Fruit trees and berry plantations (222); Transitional woodlandshrub (324) 1.00 Discontinuous urban fabric (112); Industrial or commercial units (121); Construction sites (133); Coniferous forest (312) 1.50 Broad-leaved forest (311); Mixed forest (313) 2.00 Continuous urban fabric (111) This option is not available for the time being. CadnaA - Reference Manual Stability Class D/E/N 120 6 Chapter 6 - Calculation 6.2.9.3 Nord 2000 Wind Direction (°) D/E/N The wind direction is the direction from which a wind originates (with 0° being North wind, i.e. wind blowing from North, with 180° being South wind etc.). Wind Speed (m/s) D/E/N The wind speed refers to the specified height at which the wind speed was measured (see above). Standard Deviation Wind Speed (m/s) D/E/N This is the standard deviation of the wind speed in the direction of propagation. In the documentation of Nord 2000 it says /75/: 6 „The standard deviation ... accounts for the fluctuation in wind speed in excess of what is already included in the turbulence strength. Turbulent motion is fluctuations taking place within seconds or minutes. For calculation of instantaneous sound pressure levels (the standard deviation) shall be zero. For calculation of the equivalent sound pressure level with duration above a few minutes up to a few hours, the effect of slow variations in wind speed can be taken into account by this parameter. The parameter should not be used for calculating long-term effects where the weather is basically changing during the time. Instead a procedure where the weather is divided into a number of meteorological classes should be used.“ Temperature Gradient (°/km) D/E/N The atmospheric temperature gradient in degrees centigrade per kilometer height. This gradient is negative under normal situations (temperature decrease with height, e.g. about -6°C/km or -0.006°C/m). In inversions, however, the gradient becomes positive, i.e. a temperature increase with height. CadnaA - Reference Manual 6 121 Chapter 6 - Calculation 6.2.9.3 Nord 2000 In the documentation of Nord 2000 it says /75/: „The turbulence strength corresponding to the wind Cv2 accounts for the turbulent motion of the atmosphere. The parameter is not available in standard weather data. The maximum observed value of Cv2 is approx. 0.3 m4/3s-2, and it is recommended to use a value of 0.12 m4/3s-2 unless other information is available.“ In the documentation of Nord 2000 it says /75/: „The turbulence strength corresponding to the temperature CT2 accounts for the turbulent variation of the temperature in the atmosphere. The parameter is not available in standard weather data. The maximum observed value of CT2 is approx. 0.05 Ks-2, and it is recommended to use a value of 0.008 Ks-2 unless other information is available.“ In the documentation of Nord 2000 it says /75/: „The standard deviation of fluctuations in the temperature gradient dt/dz accounts for fluctuation in temperature gradient in excess of what is already included in the turbulence strength. It is recommended to use a value of zero unless other information is available. Together with the air temperature the relative humidity is used to predict the attenuation due to air absorption. The value is normally available in standard weather data.“ CadnaA - Reference Manual Turbulence Parameter for Wind Cv2 (m4/3s-2) D/E/N Turbulence Parameter for Temperature CT2 (K/s2) D/E/N Standard Deviation of Fluctuations of the Temperature Gradient dt/dz (°C/m) D/E/N 6 122 6 Chapter 6 - Calculation 6.2.9.3 Nord 2000 Additional Information Ground Absorption In CadnaA, the ground factor G and the absorption coefficient Alpha are transformed by linear interpolation to an air resistivity according to: • for the ground factor G (as entered on the Configuration dialog, „Ground Absorption“ tab, see chapter 6.2.7, and for the object „Ground Absorption“, see chapter 3.6): ground factor G airflow resistivity (kNsm-4) 6 • 0 20000 0.33 1000 0.50 600 0.67 400 1.00 50 and for the absorption coefficient Alpha of buildings and barriers (see Chapter 3 - Obstacles): absorption coefficient Alpha airflow resistivity (kNsm-4) 0 20000 0.25 1000 0.50 600 0.75 400 1.00 50 CadnaA - Reference Manual Chapter 6 - Calculation 6.2.9.4 Ljud från vindkraftverk 6.2.9.4 6 123 Ljud från vindkraftverk 6 The same configuration settings as for Nordic Prediction Method for industrial noise apply. Please refer to chapter 6.2.9.2 "Nordic Prediction Method (1996)". CadnaA - Reference Manual 124 6 Chapter 6 - Calculation 6.2.9.4 Ljud från vindkraftverk Additional Information Propagation Model The guideline states different equations for the geometrical divergence over land and over water, for land depending on the distance r to the receiver. • propagation over land: for distances r <= 1000 m: L p , A LWA , korr 8 20 lg r 0.005 r 6 where LWA,korr A-weighted sound power level, corrected for terrain roughness and r statistical error (see below) distance source-receiver (m) for distances r > 1000 m: L p , A LWA , korr 10 20 lg r La where LWA,korr A-weighted sound power level, corrected for terrain roughness and r La statistical error (see below) distance source-receiver (m) correction calculated according to: La 10 lg 10 Li Ai / 10 10 lg 10 Li Ai r ai / 10 • where Li A-weighted sound pressure level (background level) at the receiver Ai A-weighting for octave data, 63 to 4000 Hz (dB) ai air absorption (dB/m) propagation over water: r L p , A LWA, korr 8 20 lg r La 10 lg 200 The correction term La is not evaluated by CadnaA and, thus, has to be accounted for after calculation. CadnaA - Reference Manual 6 125 Chapter 6 - Calculation 6.2.9.4 Ljud från vindkraftverk The correction for terrain roughness vh (based on the roughness length z0) is not considered by CadnaA as this is part of the emission data. This correction will have to be calculated externally and to be added to the sound power level PWL. Terrain Roughness The statistical error k is also considered to be part of the emission (see also example on page 25 of /74/). Again, this correction will have to be calculated externally and to be added to the sound power level PWL. Statistical Error The object „Ground Absorption Area“ (see chapter 3.4) can be applied in conjunction with the tab „Ground Absorption“ (see chapter 6.2.7) with "Ljud från vindkraftverk". There are two cases to be distinguished by the ground factor G: Ground Absorption • propagation over land (soft ground): G > 0.5 • propagation over water (hard ground): G <= 0.5 CadnaA - Reference Manual 6 126 6 Chapter 6 - Calculation 6.2.9.4 Ljud från vindkraftverk 6 CadnaA - Reference Manual Chapter 6 - Calculation 6.2.9.5 BS 5228 6.2.9.5 6 127 BS 5228 6 The following specifications refer to edition 2009 of the standard /84/. BS 5228 does neither account for lateral diffraction, nor for meteorological effects. By activating this option the spectral screening model of BS 5228 is applied to non-spectral sources as well (see figure F.3 in BS 5228). In this case, the attenuation due to screening at the specified frequency is used. When this option is not activated the attenuation at non-spectral sources depends just on the visibility of the top of the source from the receiver (see section F.2.2.2.1 in BS 5228). In CadnaA, this attenuation depends on the path difference z: • • • z < -0.25 m: Ascreen = 0 dB („visible“) -0.25 <= z <= 0.25 m: Ascreen = 5 dB („just visible“) z > 0.25 m: Ascreen = 10 dB („not visible“) The limits for the path differences are not stated in BS 5228, but result from a common agreement of UK resident users on how the term „just visible“ translates into a path difference. CadnaA - Reference Manual Use diagram F.3 for screening of non-spectral sources 128 6 Line sources are haul roads (F.2.5) Chapter 6 - Calculation 6.2.9.5 BS 5228 By activating this option, the propagation by line sources will no longer be influenced by soft ground. In other words, the ground attenuation being used for line sources refers always to reflective ground, independently of what ground factor G is specified. Furthermore, the CadnaA-protocol (see chapter 6.5) specifies in this case on column Kh’ no longer the divergence-ground attenuation term as specified by BS 5228 (see below), but the sum of the divergence and the angle correction according to: 6 K 'h Adiv Aangle 10 lg rsegment 1m 10 lg 180 where r is the distance from the center of the source segment to the receiver (m), is the angle of view of that source segment seen from the receiver, (degrees). In this respect, the procedure applied is similar to the one used in CadnaA for calculations according to CTRN/CRN. Explanatory Remarks: For mobile items of a plant, a separate model is used (section F.2.5 of the standard) which is not consistent with the general calculation method (section 2.3 of the standard). While the general calculation method accounts for the ground attenuation (over hard, soft, and mixed ground, see below) the receiver level LA,eq for well-defined routes, e.g. haul roads, results from the following equation: LA, eq LWA 33 10 lg Q 10 lg V 10 lg d where LWA the sound power level of the moving source, in dB(A), Q the number of vehicles/sources per hour, v the speed (km/h), d the distance from the receiver to the center of the haul road (m). The equation in section F.2.5 of the standard mixes up emission and immission. In CadnaA however, emission and immission are always treated separately. When using moving point sources (PWL-Pt) in CadnaA, the overall PWL of the line source is calculated prior to the propagation (see chapter 2.1.1 "Common Input Data"). When using other equations to specify emission it is advisable to calculate the sound power level PWL beforehand and to enter this as a calculated PWL directly. This applies, for example, when using the -33 dB correction instead of -30 dB from the equation in section F.2.5 of BS 5228. CadnaA - Reference Manual 6 129 Chapter 6 - Calculation 6.2.9.5 BS 5228 When this option is active, any obstacle (e.g. buildings, foliage, barriers etc.) located within area sources (including parking lots and optimizable sources) provide no screening for any sub-source of that area source. Obstacles within Area Source do not Shield Example 6 Area source with 2 buildings inside, option activated: sources with free propagation (with all rays displayed) With this option activated the result levels are calculated as if the obstacles were not present (i.e. no screening effect). Area source with 2 buildings inside, option deactivated: sub-sources behind the buildings are screened, sub-sources in front of buildings with free propagation (screened rays in RED) With this option deactivated lower levels result at the receiver points due to the screening effect of the obstacles inside. Nevertheless, for all other sources (i.e. sources outside of the are source’s border) the obstacles inside cause always screening. CadnaA - Reference Manual 130 6 Chapter 6 - Calculation 6.2.9.5 BS 5228 Temperature / rel. Humidity The air attenuation is calculated based on the temperature and relative humidity. Intermediate frequency values result from linear interpolation. The temperature specified serves also as the ambient temperature when calculating the exhaust stack’s directivity. Wind Speed for Directivity (m/s) The entered wind speed will be used in the calculation of the directivity of chimneys (see chapter 2.2.1 "Sound Radiation from Chimneys or Stacks"). 6 CadnaA - Reference Manual 6 131 Chapter 6 - Calculation 6.2.9.5 BS 5228 Additional Information The propagation model in BS 5228 distinguishes three kinds of situations with respect to ground attenuation. In each of these three situations the calculation in CadnaA is based on the ground factor G as being entered on the „Ground Absorption“ tab (see chapter 6.2.7). • Divergence & Ground Absorption geometrical divergence K’h for hard ground (G=0): K 'h 20 lg r 8 dB 6 where r is the distance source-receiver • geometrical divergence K’s for soft ground (G=1): K 's 25 lg r 1 dB where r is the distance source-receiver (with r >= 25 m) • geometrical divergence for mixed ground (0 < G <1): soft G K 's K 'h For all three settings the conditions expressed in section F.2.3.2.1 regarding the distance adjustments are respected. BS 5228 states that in case of a barrier being present the screening effect and the ground attenuation can just be combined for hard ground. Consequently, the correction K’h is always used for the ground attenuation when a barrier is intersecting the path. Screening BS 5228 specifies in section F.2.2.2.1 that for calculations of the noise level at a distance of 1 metre in front of a façade a correction of +3 dB has to be made. Facade Effect As already with CRTN, CadnaA does not apply this correction automatically, however controlling its use by the string variable FACADE defined on the memo-window of a receiver. Please see chapter 6.2.10.6 "CRTN", section "Facade Effect", for details on the procedure. CadnaA - Reference Manual 132 6 Chapter 6 - Calculation 6.2.9.5 BS 5228 6 CadnaA - Reference Manual 6 133 Chapter 6 - Calculation 6.2.9.6 Harmonoise 6.2.9.6 Harmonoise 6 When this option is activated the propagation calculation is performed in third-octave band width (25 to 10000 Hz). In this case with a source spectrum supplied in octave band width (31.5 to 8000 Hz), for all three thirdoctaves within an octave the same input data (PWL) is used. The result is displayed just in octave band width. Calculation in 1/3Octave Bands The main effect from this setting is that the impact of air absorption is more severe when calculating in third-octave band width resulting in a lower receiver level, especially at higher frequencies. When this option is active, any obstacle (e.g. buildings, foliage, barriers etc.) located within area sources (including parking lots and optimizable sources) provide no screening for any sub-source of that area source. for an example see chapter 6.2.9.5 "BS 5228" CadnaA - Reference Manual Obstacles within Area Source do not shield 134 6 Sources in Building/ Cylinder do not shield Chapter 6 - Calculation 6.2.9.6 Harmonoise By default, a screening effect results for sources inside buildings and cylinders as the outer walls act as barriers. In this case, prior to the calculation, a message will be displayed (dialog Consistency Check) which enables to proceed with the operation (button „Continue“). This procedure is due to the fact that buildings and cylinders are treated as open boxes within the calculation of propagation (despite they are displayed as „closed“ objects, i.e. with roof, on the 3D-Special View). 6 With this option activated, sources located inside of the geometrical borders of buildings or cylinders are not screened as if the obstacle were not present. For sources outside, those obstacles are always screening and - if any - reflecting. This option enables to model e.g. sound radiating chimneys by using point or line sources located inside the cylinder. In this case, the directivity pattern of the chimney - whether entered or selected from the default directivities - will not distorted by the cylinder’s screening edge. Example see manual „Introduction to CadnaA“, chapter 6.3 Directivity Temperature / rel. Humidity The air attenuation is calculated based on the temperature and relative humidity. Intermediate frequency values result from linear interpolation. The temperature specified serves also as the ambient temperature when calculating the exhaust stack’s directivity. Harmonoise DLLVersion After the first calculation using Harmonoise the version of the file PointToPoint.dll in the CadnaA-installation directory will be displayed. The Harmonoise DLL presently implemented in CadnaA is of version 2.020. CadnaA - Reference Manual 6 135 Chapter 6 - Calculation 6.2.9.6 Harmonoise Harmonoise method applies a specific input data set for the meteorological correction, not considering any statistical distribution for long-term averaging. A proposal on how to handle the Harmonoise model to predict long-term average levels see /3/, chapter 3.3.11. Meteorology Harmonoise offers five meteorological propagation classes depending on the following parameters: • • • • wind speed at 10 m above the ground, v (m/s) at z = 10 m, wind speed component in the direction of sound propagation at 10 m above the ground, u (z = 10 m), cloud cover in octas (i.e. as a multiple of 1/8), and time of the day (day/night). 6 Within the engineering model besides the five stability classes, eight distinct wind directions (i.e. in steps of 45°), and three wind speed classes are applied. In CadnaA, intermediate values are linearly interpolated. The stability class addressing the vertical stability of the atmosphere can be specified for the daily periods D/E/N separately. The five stability classes are characterized by day/night and cloud cover /4/: stability class day/night, cloud cover S1 day, 0/8 ... 2/8 S2 day, 3/8 ... 5/8 S3 day, 6/8 ... 8/8 S4 night, 5/8 ... 8/8 S5 night, 0/8 ... 4/8 From this a classification with respect to favorable or unfavorable propagation conditions depending on wind direction (see below) can be derived (simplified from /5/): CadnaA - Reference Manual Stability Class D/E/N 136 6 Chapter 6 - Calculation 6.2.9.6 Harmonoise wind direction (*1) stability class -90° -45° 0° 45° 90° S1: day, no clouds S2: days, clouds 50% S3: day, clouds 100% S4: night, cloudy 6 S5: night, clear sky (*1): is the angle between the wind direction and the direction of sound propagation Note: From the wind speed class and the stability class the inverse of the Monin-Obukhov length 1/L results being used to predict the height difference h above the straight ray path. Caption: very favorable favorable neutral unfavorable very unfavorable Consequently, by class S1 a vertically very unstable atmospheric condition is addressed („sunny day“), while class S5 models a stable condition („clear night“). A neutral atmospheric condition would be represented by class S3 („heavily clouded/overcast“). Wind Direction (°) D/E/N The wind direction is the direction from which a wind originates (with 0° being North wind, i.e. wind blowing from North, with 180° being South wind etc.). CadnaA - Reference Manual Chapter 6 - Calculation 6.2.9.6 Harmonoise The wind speed refers to a height of 10 m above ground. The following wind speed classification is used /4/: wind speed class wind speed at 10 m above ground v (z=10 m) W1 0 ... 1 m/s W2 1 ... 3 m/s W3 3 ... 6 m/s W4 6 ... 10 m/s W5 > 10 m/s CadnaA - Reference Manual 6 137 Wind Speed (m/s) D/E/N 6 138 6 Chapter 6 - Calculation 6.2.9.6 Harmonoise Additional Information Default Calculation Settings used by Harmonoise-DLL 6 The calculations when using Harmonoise method are performed by the dynamic link library PointToPoint.dll in the CadnaA installation directory. This DLL (Dynamic Link Library) represents the so-called „Engineering Model“ for industrial noise sources within the Harmonoise project /3/. The calculation settings of the DLL used per default have been fixed in accordance with CSTB (Centre Scientifique et Technique du Bâtiment, Grénoble/France) which has implemented the engineering propagation model. The following options are applied: • EnableAveraging option: enabled • EnableScattering option: not enabled • For all three third-octaves within an octave the same input data is used (i.e. spectrum is a step function). • The ground factor G and the absorption coefficient Alpha are transformed by linear interpolation to an air resistivity according to: for the ground factor G (as entered on the Configuration dialog, „Ground Absorption“ tab, see chapter 6.2.7, and for the object „Ground Absorption“, see chapter 3.6): ground factor G airflow resistivity (kNsm-4) 0 20000 0.33 1000 0.50 600 0.67 400 1.00 50 CadnaA - Reference Manual Chapter 6 - Calculation 6.2.9.6 Harmonoise 6 139 and for the absorption coefficient Alpha of buildings and barriers (see Chapter 3 - Obstacles): absorption coefficient airflow resistivity Alpha (kNsm-4) 0 20000 0.25 1000 0.50 600 0.75 400 1.00 50 CadnaA - Reference Manual 6 140 6 Batch Processing Chapter 6 - Calculation 6.2.9.6 Harmonoise Different meteorological configurations for a distinct situation can be processed automatically. The procedure to be followed consists of the following: • the situation file with several receiver points (in the example below: meteo.cna), • the macro-file specifying the configuration of calculation and the results to be exported (in the example below: meteo.cnm). • The macro-file is loaded into CadnaA via menu File|Open. Select the option „All Files“ from the list box „File Type“ to select the cnm file. • Upon opening of the file the batch processing start automatically and saves the results to a text file with file extension *.log (in the example below: meteo.log). 6 Examples\05_Immissions\Harmonoise File Structure of meteo.cnm An example file is provided. Follow the procedure as described above. The macro-file meteo.cnm makes use of the keywords CalcConf and ObjAtt (see CadnaA-manual „Attributes, Variables, and Keywords, chapter 3.2 and chapter 3.20). The file meteo.cna is loaded by the command: #(LoadFile, meteo.cna). The next line specifies the column headings. The keyword #(ObjAttAll, 02000000, ID) establishes a dynamic link to the name of each receiver (see CadnaAmanual „Attributes, Variables, and Keywords, chapter 3.21). The four subsequent lines define the configuration settings for meteorological classes S1 to S4 (of Harmonoise), start the calculation at receivers (using the keyword #(CalcImm)), and retrieve the results for level LP1 (using the keyword #(ObjAttAll)). The command #(QuitAtOnce) closes the file saving the result file meteo.log. CadnaA - Reference Manual 6 141 Chapter 6 - Calculation 6.2.9.7 Concawe 6.2.9.7 Concawe 6 When this option is active, any obstacle (e.g. buildings, foliage, barriers etc.) located within area sources (including parking lots and optimizable sources) provide no screening for any sub-source of that area source. Obstacles within Area Sources do not shield Example Area source with 2 buildings inside, option activated: sources with free propagation (with all rays displayed) With this option activated the result levels are calculated as if the obstacles were not present (i.e. no screening effect). CadnaA - Reference Manual 142 6 Chapter 6 - Calculation 6.2.9.7 Concawe 6 Area source with 2 buildings inside, option deactivated: sub-sources behind the buildings are screened, sub-sources in front of buildings with free propagation (screened rays in RED) With this option deactivated lower levels result at the receiver points due to the screening effect of the obstacles inside. Nevertheless, for all other sources (i.e. sources outside of the are source’s border) the obstacles inside cause always screening. Sources in Building/ Cylinder do not shield By default, a screening effect results for sources inside buildings and cylinders as the outer walls act as barriers. In this case, prior to the calculation, a message will be displayed dialog Consistency Check) which enables to proceed with the operation (button „Continue“). This procedure is due to the fact that buildings and cylinders are treated as open boxes within the calculation of propagation (despite they are displayed as „closed“ objects, i.e. with roof, on the 3D-Special View). With this option activated, sources located inside of the geometrical borders of buildings or cylinders are not screened as if the obstacle were not present. For sources outside, those obstacles are always screening and reflecting. This option enables to model e.g. sound radiating chimneys by using point or line sources located inside the cylinder. In this case, the directivity pattern of the chimney - whether entered or selected from the default directivities - will not distorted by the cylinder’s screening edge. CadnaA - Reference Manual 6 143 Chapter 6 - Calculation 6.2.9.7 Concawe see manual „Introduction to CadnaA“, chapter 6.3 Directivity Example The air attenuation is calculated based on the temperature and relative humidity. Intermediate frequency values result from linear interpolation. The temperature specified serves also as the ambient temperature when calculating the exhaust stack’s directivity. Temperature / rel. Humidity In the CONCAWE propagation model the meteorological correction is named „attenuation factor for meteorological effects K4“ /1/. The attenuation is a function of frequency, distance, and meteorological category. Meteorology With non-spectral sources CadnaA applies the correction K4 independent of frequency as stated in CONCAWE, appendix II, section 2. Thus, the spectral K4 at the entered frequency (500 Hz per default) is not used. Despite the specification in CONCAWE, appendix II, not to use the attenuation curves for receiver distances below 100 m, in CadnaA the value of K4 for d<100 m is linearly interpolated to 0 dB at the source location. CadnaA - Reference Manual 6 144 6 Stability Class D/E/N Chapter 6 - Calculation 6.2.9.7 Concawe The assessment of atmospheric temperature gradient is replaced by use of Pasquill Stability Categories A to G (for periods D/E/N separately). The definition of the categories depends on wind speed, time, and cloud cover: Wind Speed * m/s 6 Day Time, Incoming Solar Radiation (mW/cm²) > 60 30-60 < 30 Overcast 1 hour before Sunset or after Sunrise <=1.5 A A-B B C 2.0 - 2.5 A-B B C 3.0 - 4.5 B B-C 5.0 - 6.0 C > 6.0 D Night-Time, Cloud Cover (octas) 0-3 4-7 8 D F or G** F D C D F E D C C D E D D C-D D D D D D D D D D D D D D Notes: *: wind speed is measured to the nearest 0.5 m/s **: category G is restricted to night-time with less than 1 octa of cloud and a wind speed of less than 0.5 m/s Based on literature, category A represents a strong lapse condition (large temperature decrease vs. height), category G a temperature inversion observed early on a clear morning. Categories E and F apply to slight inversions. However, inversion conditions, particularly those over water, are highly variable and not easy to predict. The acoustical effect depends on additional factors (e.g. geometry). From this classification six new meteorological categories have been defined, based an a combination of Pasquill Stability Categories (representing the temperature gradient) and vector wind speeds (v (z=10 m) in m/s). The effect on the attenuation is indicated by the arrow. CadnaA - Reference Manual Chapter 6 - Calculation 6.2.9.7 Concawe 6 145 Pasquill Stability Category Meteorological Category A, B C, D, E F, G 1 v < -3.0 - - 2 -3.0 <= v <-0.5 v <= -3.0 - 3 -0,5 <= v < + 0.5 -3.0 <= v < -0.5 v < -3.0 4 (*1) +0.5 <= v <+3.0 -0.5 <= v < +0.5 -3.0 <= v < -0.5 5 v >= +3.0 +0.5 <= v < +3.0 -0.5 <= v < +0.5 6 - v >= +3.0 +0.5 <= v < +3.0 (*2) 6 Notes: *1: category with assumed zero meteorological influence *2: For speeds v >= +3.0 also category 6 is assumed. In CadnaA, the Pasquill Stability Category D at wind speed 0 m/s is selected by default, resulting in the meteorological category 4 with a correction K4=0 dB. The wind direction is the direction from which a wind originates (with 0° being North wind, i.e. wind blowing from North, with 180° being South wind etc.). Wind Direction (°) D/E/N CONCAWE-method does not specify at what height the wind direction and speed shall be assessed. Wind Speed (m/s) D/E/N The commonly used height for evaluation of wind speeds in meteorology is 10 m above ground (plus further criteria regarding nearby obstacles etc.). CadnaA - Reference Manual 146 6 Interpolate Meteorological Category Chapter 6 - Calculation 6.2.9.7 Concawe As the velocity vector of the wind in source-receiver direction is relevant for the calculation of the meteorological correction level steps may result between categories. This option causes to smoothen the noise contours at the limits of areas with different meteorological categories by interpolation. Example 6 horizontal grid from a point source with meteo settings: - stability class: A - wind direction: 180° - wind speed: 5.0 m/s option „Interpolate meteorological Category“ deactivated as above option „Interpolate meteorological Category“ activated CadnaA - Reference Manual 6 147 Chapter 6 - Calculation 6.2.9.7 Concawe Different meteorological configurations for a distinct situation can be processed automatically. The procedure to be followed consists of the following steps: • the situation file with several receiver points (*.cna), • the macro-file specifying the configuration of calculation and the results to be exported (*.cnm). • The macro-file is loaded into CadnaA via menu File|Open. Select the option „All Files“ from the list box „File Type“ to select the cnm-file. • Upon opening of the file the batch processing start automatically and saves the results to a text file with file extension *.log. An example file is provided. The settings in the example refer to the method „Harmonoise“. Please see chapter 6.2.9.6 for more details. CadnaA - Reference Manual Batch Processing 6 Examples\05_Immissions\Harmonoise_Concawe 148 6 Chapter 6 - Calculation 6.2.9.7 Concawe Additional Information Ground Attenuation K3 6 The ground attenuation K3 is controlled in CadnaA via the „Default Ground Factor“ G specified on tab „Ground Absorption“ (see chapter 6.2.7). With the default ground factor G=0 reflective ground is assumed (leading to K3=-3 dB), while with a default ground factor G>0 absorbing ground is considered. The object „Ground Absorption“ can be used to model mixed ground (with G=0 or G>0). In this case, CadnaA just evaluates the ray’s path length across the absorptive ground (see CONCAWE-report, section 5.1.3). Meteorological Correction K4 Despite the specification in CONCAWE, appendix II, not to use the attenuation curves for receiver distances below 100 m, in CadnaA the value of K3 for d<100 m is linearly interpolated to 0 dB at the source location. In CONCAWE, the so-called „vector wind velocity“ for each ray path based on the entered overall wind velocity and direction is evaluated (see chapter 2.5 of /1/) considering the angle between the entered wind direction and the ray‘s path. Thus, the relevant speed for K4 can be smaller than the specified wind speed resulting in a different meteo category. For downwind the cosine is positive, for upwind negative. Example 1: Relevant wind speed in a downwind situation CadnaA - Reference Manual Chapter 6 - Calculation 6.2.9.7 Concawe 6 149 6 Example 2: Relevant wind speed in an upwind situation The function for gamma using the grazing angle is limited to >=0 (i.e. no negative values for ), Thus, the function plotted in figure 9 of CONCAWE report is in CadnaA assumed to end at =0 asymptotically (as a specification is missing). Source/Receiver Height Correction K5 In the CONCAWE-report, section 2.7, it says: Barrier Attenuation K6 „The presence of a discrete barrier may reduce ground effects and it is proposed that this be covered by recalculating K5 based an the barrier height and barrier-receiver distance.“ Furthermore, it says in section 5.1.6: „This is not, however, necessary if the barrier is a topographical feature.“ This proposal is not respected in CadnaA as it causes level jumps due to different path length differences. CadnaA - Reference Manual 150 6 Distance Source-Receiver 6 Type of Wind & Wind Data Chapter 6 - Calculation 6.2.9.7 Concawe In CONCAWE, it is unclear what the mentioned „distance d“ exactly means, the 2D or the 3D distance. On page 8 of the CONCAWE-report it says “d source – receiver distance” (i.e. not specifying whether 2D or 3D distance is meant). This has, with respect to the different attenuation terms, the following consequences with regard to the implementation in CadnaA: • In CONCAWE, chapter 5.1.1, the attenuation term K1 is based clearly on 3D distance (CadnaA uses 3D distance for K1). • In CONCAWE, chapter 5.1.4, regarding the attenuation term K4 nothing is said whether to use 2D or 3D distance (CadnaA uses 2D distance). • In CONCAWE, chapter 5.1.5, the attenuation term K5 in the equation for psi the distance d must be the 2D distance (as 3D distance does not make sense). CONCAWE does not specify what kind of wind regarding stability class, wind direction and wind speed is to be used. For example, it does not say whether the wind data should be based on average values, on peak values, or on the „representative/dominating wind“ at a location or in an area. Further, it is not said in CONCAWE at what height the wind direction and speed shall be assessed. Furthermore, CONCAWE does not address the objective on how to proceed in order to assess a long-term average level based on several distinct wind situations. CadnaA - Reference Manual 6 151 Chapter 6 - Calculation 6.2.9.8 NMPB-Industry 2008 6.2.9.8 NMPB-Industry 2008 6 Three options for lateral diffraction are available for selection: • none: No lateral diffraction considered, just the direct path sourcereceiver is evaluated. • only one object: Lateral diffraction is not calculated if more than one object intersects the line connecting the source to the receiver point. • some objects: The two shortest possible convex rays around the arrangement of objects are determined and used for the calculation of the lateral diffraction. Lateral Diffraction This setting defines the distance between source and receiver for which lateral diffraction is taken into account. The default value is 1000 m. if Distance smaller (m) When this option is active, any obstacle (e.g. buildings, foliage, barriers etc.) located within area sources (including parking lots and optimizable sources) provide no screening for any sub-source of that area source. Obstacles within Area Sources do not shield see chapter 6.2.9.7 "Concawe" Example CadnaA - Reference Manual 152 6 Sources in Building/ Cylinder do not shield Chapter 6 - Calculation 6.2.9.8 NMPB-Industry 2008 By default, a screening effect results for sources inside buildings and cylinders as the outer walls act as barriers. For further details and an example see chapter 6.2.9.7 "Concawe". 6 Temperature / rel. Humidity The air attenuation is calculated based on the temperature and relative humidity. Intermediate frequency values result from linear interpolation. The temperature specified serves also as the ambient temperature when calculating the exhaust stack’s directivity. Meteorology Via the button „Meteorology“ the percentage of „favorable conditions“ in wind sectors stepped by 20° can be specified for the time periods D/E/N separately. The percentage refers to the assessment interval, usually an entire year. List Box / Locations For calculations using NMPB 2008 the following items from the list box apply: • • • • (default): favorable conditions D/E/N = 50/75/100% (favorable): favorable conditions D/E/N = 100/100/100% (homogène): favorable conditions D/E/N = 0/0/0% XXX (2) and XXX (3) with „XXX“ representing a French town and region: data of the percentage of favorable conditions for two (2: D, N) or three time periods (3: D, E, N) according to NMPB 2008. For further details see chapter 6.2.10.4 "NMPB-Routes 2008". Use reference DLL This option is deactivated by default. In this case, CadnaA code is used for the calculation implemented based on the printed documentation of NMPB 2008. CadnaA - Reference Manual Chapter 6 - Calculation 6.2.9.8 NMPB-Industry 2008 6 153 By activating this option the later released, but officially provided reference DLL (developed by the French consortium) is used for the calculation. This option requires to copy the reference DLL (PropagationNMPB.dll) into the respective CadnaA installation directory. The DLL is not part of the CadnaA installation procedure and is, therefore, distributed separately. 6 CadnaA - Reference Manual 154 6 Chapter 6 - Calculation 6.2.9.8 NMPB-Industry 2008 6 CadnaA - Reference Manual 6 155 Chapter 6 - Calculation 6.2.9.9 CNOSSOS-EU 6.2.9.9 CNOSSOS-EU 6 Three options for lateral diffraction are available for selection: • none: No lateral diffraction considered, just the direct path sourcereceiver is evaluated. • only one object: Lateral diffraction is not calculated if more than one object intersects the line connecting the source to the receiver point. • some objects: The two shortest possible convex rays around the arrangement of objects are determined and used for the calculation of the lateral diffraction. Lateral Diffraction This setting defines the distance between source and receiver for which lateral diffraction is taken into account. The default value is 1000 m. if Distance smaller (m) When this option is active, any obstacle (e.g. buildings, foliage, barriers etc.) located within area sources (including parking lots and optimizable sources) provide no screening for any sub-source of that area source. Obstacles within Area Source do not Shield (for an example see chapter 6.2.9.1) CadnaA - Reference Manual 156 6 Sources in Building/ Cylinder do not shield Chapter 6 - Calculation 6.2.9.9 CNOSSOS-EU By default, a screening effect results for sources inside buildings and cylinders as the outer walls act as barriers. (for more information on this option see chapter 6.2.9.1) Temperature / rel. Humidity The air attenuation is calculated based on the temperature and the relative humidity according to ISO 9613-1. Intermediate frequency values result from linear interpolation. The temperature specified serves also as the ambient temperature when calculating the exhaust stack’s directivity. 6 Meteorology The octave band at center frequency of 31.5 Hz is excluded explicitly from the CNOSSOS-EU calculation model. Via the button „Meteorology“ the percentage of „favorable conditions“ in wind sectors stepped by 20° can be specified for the time periods D/E/N separately. The percentage refers to the assessment interval, usually an entire year. For further details on this dialog, see chapter 6.2.10.4, section "Meteorology". No hint is possible what percentage may apply to an unknown location when just a general description of the local orography is available. CadnaA - Reference Manual 6 157 Chapter 6 - Calculation 6.2.9.10 HJ 2.4 (2009) 6.2.9.10 HJ 2.4 (2009) 6 Three options for lateral diffraction are available for selection: • none: No lateral diffraction considered, just the direct path sourcereceiver is evaluated. • only one object: Lateral diffraction is not calculated if more than one object intersects the line connecting the source to the receiver point. • some objects: The two shortest possible convex rays around the arrangement of objects are determined and used for the calculation of the lateral diffraction. Lateral Diffraction This setting defines the distance between source and receiver for which lateral diffraction is taken into account. The default value is 1000 m. if Distance smaller (m) The air attenuation is calculated based on the temperature and the relative humidity according to ISO 9613-1. Intermediate frequency values result from linear interpolation. The temperature specified serves also as the ambient temperature when calculating the exhaust stack’s directivity. Temperature / rel. Humidity CadnaA - Reference Manual 158 6 Chapter 6 - Calculation 6.2.9.10 HJ 2.4 (2009) 6 CadnaA - Reference Manual Chapter 6 - Calculation 6.2.10 Road Tab 6.2.10 6 159 Road Tab Information on the calculation options for the following standards or guidelines for industry can be found in the German version of the CadnaA reference manual: RVS 4.02 (Austria) StL-86 (Switzerland) DIN 18005 (1987, Germany) The subsequent table lists the main characteristics of the propagation models for road noise as treated in the chapters explaining the configuration options. A special focus is put to the type of modeling being used for the various attenuating effects in sound propagation. Table „Propagation Models Road“ A further table describes the properties of obstacles and special-objects in CadnaA with each propagation model. Table „Obstacles and Special-Objects“ CadnaA - Reference Manual 6 160 6 Chapter 6 - Calculation 6.2.10 Road Tab Propagation Models Road 6 No Option or Propagation Effect Standard / Guideline 1 calculation using A-weighted levels yes yes 2 spectral calculation no no 3 geometrical attenuation (divergence) line source propagation (includes air absorption) LAeq/LAFmax: line/point source propagation 4 attenuation by air absorption considered within the geometrical attenuation not considered 5 handling of ground reflections not by image sources, but by an algorithm considering ground attenuation and meteorological effects in common (see below) concept of reflection planes 6 handling of reflections at obstacles just up to 1st order of reflection, higher orders of reflection applying a „Correction for multiple Reflections“, in CadnaA optionally: calculation to up the 20th order, condition for reflection considers obstacle’s size and absorption coefficient/reflection loss of the reflector see RLS-90 7 attenuation due to ground effect (ground attenuation) for A-weighted levels (not applying ground factor G) soft or hard ground only (combined with screening) 8 attenuation due to screening (at objects) single and double diffraction based on the path length difference of the direct path via the obstacles, screening effect does not depend on wavelength (as just for A-weighted levels), negative path difference causes no screening concept of effective height 9 handling of lateral diffraction not considered, in CadnaA optionally available not considered 10 handling of multiple obstacles in ray path based on the path length difference of the direct path across all obstacles („ribbon band method“) using the most efficient screen 11 attenuation due to screening (terrain) screening by terrain not treated explicitly, In CadnaA the algorithm for multiple screening objects is applied. as with multiple screens 12 handling of meteorological effects (wind) not treated explicitly as being part of the ground attenuation (meteorological correction is part of the screening calculation), in CadnaA optional application of Cmet accord. to ISO 9613-2, with calculations acc. to VBUS: applies Cmet with C0,D/E/N=2/1/0 dB not available 13 attenuation due to foliage not considered, in CadnaA optionally accord. to VDI 2714 not available 14 attenuation due to built-up areas not considered, in CadnaA optionally accord. to VDI 2714 not available RLS-90 (1990) Nordic (1996) REMARK: „acoustical Transparency“ of buildings not available CadnaA - Reference Manual 6 161 Chapter 6 - Calculation 6.2.10 Road Tab Standard / Guideline NMPB (1996) CRTN TNM No Czech Method SonRoad NMPB (2008) CNOSSOS-EU yes yes yes yes yes yes yes 1 yes (octaves, 125 to 4000 Hz) no yes (1/3 octaves) no yes (1/3 octaves) yes (1/3 octaves, 100 to 5000 Hz) yes (for octaves 63 Hz to 8000 Hz, + 31.5 Hz 2 point source propagation (4r2) in CadnaA: segmented line source point source propagation (4r2) point source propagation (4r2) point source propagation (4r2) point source propagation (4r2) point source propagation (4r2) 3 yes (for 15°C and 70% r.h.) not considered acc. ISO 9613-1 (e.g. 20°C, 50%) combined with ground att. acc. ISO 9613-1 (for 15°C, 70%) acc. ISO 9613-1 (for 15°C, 70%) yes (acc. to ISO 9613-1) 4 algorithmic, not by image sources algorithmic, not by image sources complex ground impedance algorithmic, not by image sources complex ground impedance algorithmic, not by image sources algorithmic incl. ground absorp. 5 no mult. reflect. correction by default, optional in CadnaA not using image sources (optional in CadnaA) in CadnaA: via absorption coeff./reflect. loss of reflector see RLS-90 using complex reflection factor & phase relation no mult. reflect. correction by default, optional in CadnaA yes 6 spectral model (for favorable: ISO 9613-2, for homogeneous specific) empirical correction via transfer table from airflow resistivity to ground factor G combined ground and meteorological correction via transfer table from airflow resistivity to ground factor G spectral model (for favorable: ISO 9613-2, for homogeneous specific) homogeneous & favorable conditions using ground factor G 7 based on path length difference based on path length difference diffraction model using Fresnelzones & complex ground impedance see RLS-90 using path length difference (ISO 9613-2), ground reflection based on Fresnel-zones based on path length difference single & double diffr., includes ground effect, using image source method 8 not considered not considered not considered see RLS-90 not considered not expressively considered yes, at 2 vertical edges (incl. ground abs.) 9 see RLS-90 inverse energetic sum of individual barrier corrections via path length difference see RLS-90 via path length difference via path length difference via path length difference (convex hull) 10 see RLS-90 as with multiple screens (no lateral diffraction) as with multiple screens see RLS-90 as with multiple screens as with multiple screens see ISO 9613-2 11 for homogeneous & favorable prop. cond., energetic addition not available not available not available, optional in CadnaA: using Cmet for homogeneous & favorable prop. cond. (see NMPB) for homogeneous & favorable prop. cond., energetic addition for homogeneous & favorable prop. cond., energetic addition 12 not available not available in CadnaA not available not available available not available not available 13 not available not available in CadnaA not available not available not available not available not available 14 CadnaA - Reference Manual 6 162 6 Chapter 6 - Calculation 6.2.10 Road Tab Obstacles and Special-Objects 6 No Object Type/ Option Standard / Guideline 1 building single and multiple diffraction for edges parallel to the ground based on the shortest path difference, no lateral diffraction via the vertical edges by default, no reflection or by input of absorption coefficient/reflection loss, no acoustical transparency see RLS-90 2 cylinder single and multiple diffraction for edges parallel to the ground based on the shortest path difference, no lateral diffraction by default, no reflection or by input of absorption coefficient/reflection loss, reflection up to 1st order see RLS-90 3 barrier single and multiple diffraction for edges parallel to the ground based on the shortest path difference, no lateral diffraction by default, no reflection or by input of absorption coefficient/reflection loss see RLS-90 4 floating barrier no diffraction via the lower edge (screening edge without diffraction), otherwise see barrier see RLS-90 5 barrier with cantilever cantilever is totally absorbing (no reflection), calculation of the path length difference valid for receivers/grid points outside and below the cantilever, otherwise see barrier not available (due to „effective height“ concept) 6 bridge plate diffraction calculation for horizontal plate only (inclined plate approximated to horizontal plate), screening calculation valid for sources above the bridge plate (diffraction downwards), no reflection-induced level increase below the bridge plate (as ground is not modeled by mirror sources) see RLS-90 7 embankment acts as a double barrier, diffraction for direct path (without lateral diffraction), no absorptive/reflective properties see RLS-90 8 ground absorption area not relevant (generalized ground attenuation) in CadnaA: using ground factor G (soft/hard only) 9 built-up area/ foliage not relevant by default, optionally accord. to VDI 2714 not available 10 3D-reflector screening calculation based on the shortest path length difference, plus two lateral paths, diffraction can be suppressed for up to 32 edges, no reflection or by input of absorption coefficient/reflection loss, reflection up to 1st order, no summation of diffraction effects via multiple edges, no multiple diffraction not available (due to „effective height“ concept) 11 self screening additional feature in CadnaA: causes screening effect downwards, additional with left/ right available (fixed to the road, screening just for the own road source) see RLS-90 12 additional width/ parapet L/R parapet left/right available, parapet length can be restricted using station marks, additional width just for ground absorption with no effect with RSL-90 see RLS-90 RLS-90 Nordic (1996) REMARK: The embankment is not considered in the triangulation! CadnaA - Reference Manual 6 163 Chapter 6 - Calculation 6.2.10 Road Tab Standard / Guideline NMPB (1996) CRTN TNM Czech Method No SonRoad NMPB (2008) CNOSSOS-EU see RLS-90 see RLS-90 numerical diffraction model see RLS-90 numerical diffraction model see RLS-90 see RLS-90, but for homogeneous & favorable conditions 1 see RLS-90 see RLS-90 see above see RLS-90 see above see RLS-90 for homogeneous & favorable conditions 2 see RLS-90 see RLS-90 see above see RLS-90 see above see RLS-90 see RLS-90, but for homog. & favorable cond. 3 see RLS-90 see RLS-90 not available see RLS-90 not available see RLS-90 see RLS-90 4 not available not available not available not available not available not available see RLS-90 5 see RLS-90 see RLS-90 available see RLS-90 available see RLS-90 see RLS-90 6 see RLS-90 see RLS-90 available see RLS-90 available see RLS-90 see RLS-90 7 using ground factor G (for favorable and homogeneous) empirical ground correction (chart) from ground factor G transferred to airflow resistivity not relevant from ground factor G transferred to airflow resistivity using ground factor G (for favorable and homogeneous) yes, using ground factor G (for favorable and homogeneous) 8 not available not available not available in CadnaA (for the time being) not available not available in CadnaA (for the time being) not available no effect 9 see RLS-90 see RLS-90 not available (not compatible with TNM diffraction model) see RLS-90 not available not available not available 10 see RLS-90 see RLS-90 not available (not covered by TNM diffract. model) see RLS-90 available see RLS-90 see RLS-90 11 see RLS-90 see RLS-90 available (used to apply correct road width) see RLS-90 available see RLS-90 see RLS-90 12 CadnaA - Reference Manual 6 164 6 Chapter 6 - Calculation 6.2.10 Road Tab 6 CadnaA - Reference Manual Chapter 6 - Calculation 6.2.10.1 RLS-90 6.2.10.1 6 165 RLS-90 6 Dialog Configuration, tab „Road“ for RLS-90 (with option „strictly accord. to RLS-90“ deactivated) With the check box „Strictly according to RLS-90“ activated, CadnaA calculates using the following settings: • • • • • only the first-order reflections, irrespective of the order of reflection specified on the „Reflection“ tab, no lateral diffraction at obstacles, no attenuation due to foliage and built-up areas, no meteorological correction, and the two outermost lanes of a road are calculated as separate line sources with a height of 0.5 m above road. All other settings made on the „Reflection“ tab, "Conditions for Calculation of Reflection", such as the search radius for reflecting objects, will apply even when the option „Strictly according to RLS-90“ is activated (see chapter 6.2.8 "Reflection Tab"). CadnaA - Reference Manual Strictly according to RLS-90 166 6 Chapter 6 - Calculation 6.2.10.1 RLS-90 Calc exactly one reflection order With this option deactivated the maximum order of reflection is specified via the „Reflection“ tab (see chapter 6.2.8 "Reflection Tab"). No Lateral Diffraction When this option is deactivated the lateral diffraction will be considered which is normally not the relevant to the receiver level due to the extension of the road sources (line sources) in normal situations. 6 no lateral diffraction by default, option „Strictly according to RLS-90“ activated (short road section) No Housing Attenuation with lateral diffraction, option „Strictly according to RLS-90“ and „No Lateral Diffraction“ deactivated By default, the attenuation by built-up areas is not considered by RLS-90. When this option is deactivated the CadnaA-object „Built-Up Area“ causes a screening effect. The housing attenuation DG is calculated accord. to VDI 2714 (see chapter 3.5 "Built-Up Areas and Foliage"). This value is not displayed on the calculation protocol in a separate column (see CadnaA-manual „Attributes, Variables, and Keywords“, chapter "Chapter 6 - Protocol Abbreviations"). CadnaA - Reference Manual 6 167 Chapter 6 - Calculation 6.2.10.1 RLS-90 By default, the attenuation by foliage is not considered by RLS-90. When this option is deactivated the CadnaA-object „Foliage“ causes a screening effect. The attenuation due to foliage DG is calculated accord. to VDI 2714 (see chapter 3.5 "Built-Up Areas and Foliage"). This value is not displayed in a separate column on the calculation protocol. By default, the center lines of the outermost lanes of a road are the emission lines in RLS-90 (at a height of 0.5 m). When this option is deactivated just the road’s center line represents the emission line. vertical grid, perpendicular to the road’s axis: option „Strictly according to RLS-90“ activated Calc outer Lanes separately 6 vertical grid: option „Strictly according to RLS-90“ and „Calc outer Lanes separately“ deactivated No meteorological correction is established by RLS-90. In CadnaA, nevertheless, the meteorological effect can be considered by deactivation of this option. In this case, the settings on the list box „Meteorology“ on the „Industry“ tab are relevant. No Foliage Attenuation No Meteorology (Cmet see Industry) The value of Cmet will be calculated according to ISO 9613-2. This value is not displayed on the calculation protocol in a separate column. see also: chapter 6.2.9.1 "ISO 9613", section "Meteorology" relevant for Germany only! The German guideline VBUS is selectable on the „Road“ tab with RLS-90 selected. The main modifications compared to the original procedure from RLS-90 are: CadnaA - Reference Manual Calculation accord. to VBUS 168 6 6 Displaying the value of Cmet Chapter 6 - Calculation 6.2.10.1 RLS-90 • The setting for lateral diffraction is not possible any longer. • The calculation includes the meteorological correction Cmet (C0 for Day/ Evening/Night is 2/1/0 dB). When not considering Cmet and with the same emission D/E/N a level difference between Lden and Ln of 6.395 dB results. Since Cmet is automatically taken into account in CadnaA, the difference is usually smaller than this value. • From MDTD values the number of vehicles per hour M (Day/Evening/ Night) are calculated according to VBUS (different from RLS-90). The value of Cmet when calculating road noise accord. to RLS-90 can be displayed for raids with a road width of 0 m. Different values result for the two emission lines of roads with a finite road width (the values of which, however, cannot be displayed using the procedure described in the following). Proceed as follows: • First, deactivate the option „No Meteorology (Cmet see Industry)“ and enter - for example - the following values for C0 on the „Industry“ tab: D/E/N = 3/2/1 dB (for ISO 9613). • Activate the option „Write Protocol“ on the Calculation|Protocol menu. • Start the calculation by clicking on the pocket calculator symbol on the toolbar. • Open the protocol „Print“|Preview“. via Calculation(|Protocol menu, button CadnaA - Reference Manual Chapter 6 - Calculation 6.2.10.1 RLS-90 • When subtracting the individual attenuation terms from the emission value you will appreciate that not the receiving level as shown results, but that for every segment a difference remains. • In order to display this difference on the protocol the road source is converted into a line source (via the dialog Modify Objects|Convert to, „Road“ into „line Source“). 6 169 With this, the emission parameter will be converted according to: LwA " Lm , E 19.2 dB As the source height of the road is 0.5 m above ground, the line source needs to get lifted up to 0.5 m first. • Open again the dialog Modify Objects|Modify Attribute for the object „Line Source“ and click OK. • On the dialog Modify Attribute, select the attribute HA form the list box and enter for „Arithmetic|New Value“ 0.5 m. After click on OK the relative height of the line sources is set to 0.5 m. • Start the calculation by clicking on the pocket calculator symbol once more. • Open the protocol (Calculation|Protocol menu, button „Print“|Preview“). The values for Cmet displayed on the protocol are those relevant for the road noise calculation. The receiver level and the further attenuation terms displayed on the protocol are, however, not relevant as the result from ISO 9613-2 and not from RLS-90. CadnaA - Reference Manual 6 170 6 Chapter 6 - Calculation 6.2.10.1 RLS-90 6 CadnaA - Reference Manual 6 171 Chapter 6 - Calculation 6.2.10.2 Nordic Prediction Method (1996) 6.2.10.2 Nordic Prediction Method (1996) 6 Dialog Configuration, tab „Road“ for Nordic Prediction Method (1996), option „Calc maximum Pass-By-Level“ activated With this option deactivated the maximum order of reflection is specified via the „Reflection“ tab (see chapter 6.2.8 "Reflection Tab"). Calc exactly one Reflection Order see also 2.4.3 Nordic Prediction Method 1996 By default, the center lines of the outermost lanes of a road are the emission lines (at a height of 0.5 m). As in NPM just the road’s center line is the emission line, this option has to be deactivated. When active, the emission level of each outer lane is -3 dB compared with the road‘s axis being the emission line. The total emitted sound power of the entire road is, however, the same in both cases (see chapter 6.5 "Calculation Protocol"). According to NPM, when screening occurs, the source location for receivers behind the barrier is shifted to the barrier’s top edge. CadnaA - Reference Manual Calc outer Lanes separately 172 6 Calc maximum PassBy-Level Chapter 6 - Calculation 6.2.10.2 Nordic Prediction Method (1996) The A-weighted maximum sound pressure level LAFmax is an additional descriptor of noise from road traffic in Nordic Prediction Method /73/. The different corrections are calculated in complete analogy with those of the Aweighted equivalent continuous sound pressure level LA,eq with the one exception that the shortest distance source-receiver is used instead of the distance of calculation. To calculate maximum levels, CadnaA moves a point source along each road according to its speed and specified sampling interval. The source is starting from either ends of the road due to the two emission lines representing the road where different corrections may apply (e.g. gradient correction). The maximum level for this point source for each position with the specified sound power level and length is calculated. 6 LAFmaxX% Enter the percentage of vehicles X% exceeding the calculated maximum level LAFmax (default value: 5%). For details of the calculation see chapter 2.4.3. Sampling Interval (s) In order to determine the highest level, CadnaA shifts the source along the road in steps based on the sampling interval (in seconds). The default value for the sampling interval is 0.1 seconds. Consequently, the resulting distance difference between two source positions is: s v tsampling 1000 3600 where s: distance steps (m) v: speed (km/h), as entered on dialog Road for „Autos“ t: sampling interval (s) Example The maximum level for the road is calculated using the default sampling interval of 0.1 seconds. The maximum speed for autos is 100 km/h resulting in a sampling distance of: s 100 0.1 1000 2.78 m 3600 The stated maximum level is the maximum level from all sub-sources. CadnaA - Reference Manual 6 173 Chapter 6 - Calculation 6.2.10.2 Nordic Prediction Method (1996) This option enables to calculate the number of events NATd/NATn above the entered threshold level from the hourly traffic counts (for details of the prescription see chapter 2.4.3). Calculation of Numbers above Threshold (NATs) With just the option „Calc maximum Pass-By-Level“ active a threshold level of 70 dB(A) is applied always. By activating this option any other threshold level can be entered. Further, the following additional settings are required: • The evaluation parameters NATd (for Day) and NATn (for Night) are selected, e.g. as 3rd and 4th evaluation parameters (see chapter 6.2.5. • The length of the evaluation periods Day (e.g. 16 h) and Night (e.g. 8 h) periods has to be set on the „Reference Time“ tab by entering the letters D/N for the respective hours (see chapter 6.2.4). This holds especially when using diurnal patterns as road traffic figures. When entering the emission level LAeq*,10m directly neither the maximum Pass-By-Level, nor NATs can be calculated. When this option is activated, the shape of terrain is approximated by at least a single or several planes of reflection when calculating the ground effect. 6 The use of reflection planes is required with strict application of Nordic Prediction Method (NPM). The intention with this approach is to model the direct path and the reflected path (as reflected by the ground) separately. Furthermore, NPM states that: „If more than one valid plane of reflection can be found, the one giving the highest noise level shall be selected.“ The principle of the procedure to construct the plane/s of reflection as simple terrain slope is studied (see figure below). CadnaA - Reference Manual Calc planes of reflection 174 6 6 Chapter 6 - Calculation 6.2.10.2 Nordic Prediction Method (1996) Constructing the reflection plane in Nordic Prediction Method (NPM) The black line represents the terrain slope between source and receiver. In this simple scenario, two reflection planes can be constructed (each with different source and receiver heights referring to the respective reflection plane). According to the above rule the reflection plane giving the highest level for each receiver point is relevant. In conjunction with grid calculations the effect of this rule becomes obvious: At some grid point the relevant reflection plane switches from one to another causing a level jump on the grid (see figures below). Vertical grid: road on plane ground, reflecting ground (G=0), highest level occurs from reflection plane 2 (see before) for the entire grid, no ground effect to the right of the road as highest level occurs from plane 2 assuming even ground Vertical grid: road on slope, reflecting ground (G=0), considering reflection plane 1 (see above) causing ground effect to the right and level jumps to the left of the road CadnaA - Reference Manual Chapter 6 - Calculation 6.2.10.2 Nordic Prediction Method (1996) According to Nordic Prediction Model, section 2.4.1.4, the vertical deviation from the real terrain shall not exceed +/- 1 m. In addition, it is stated: „+/0.5 m desirable for „hard“ ground“. 6 175 Maximum Deviation (m) In CadnaA, the default value is 1 meter. The smaller this value the more reflection planes are to be generated, increasing also the calculation time. By activating this option the screening model is extended by the „Correction for Thick Screens“ DeltaLts according to part 2, section 2.6.4. Use Correction for Thick Screen DeltaLts This hint refers to the following settings on the „Industry“ tab: Other Properties: See Industry • • • option „lateral diffraction“ option „if distance smaller“ temperature/relative humidity CadnaA - Reference Manual 6 176 6 Chapter 6 - Calculation 6.2.10.2 Nordic Prediction Method (1996) Further Information Ground Absorption In NPM, the ground can either be acoustically „soft“ or „hard“. There are no specifications for intermediate ground properties. In CadnaA, the ground factor G is used to distinguish both cases (see chapter 6.2.7 "Ground Absorption Tab"): • soft ground: G > 0.5 (enter G=1) • hard ground: G <= 0.5 (enter G=0) According to NPM, the valid ground type for the situation is the ground type (absorption factor G) in the area of the reflection point +/- 10 m. In CadnaA, it depends on the ground absorption factor between the source line and the reflection point (resp. line) whether soft or hard ground is considered. 6 Option „Roads/Parking Lots are reflecting (G==0)“ Since NPM does account for mixed ground, the option „Roads/Parking Lots are reflecting (G==0)“ on the „Ground Absorption“ tab (see chapter 6.2.7) should be deactivated. Otherwise, in case of default G==1 and this option activated propagation effects will result for receiver or grid points close to or in direction of the road‘s axis (or of road segments). In this case, these rays cause a higher level due to reflection by the road surface along their path. This will lead to unsteady noise contours and level jumps. Default G==1 and option „Roads/Parking Lots are reflecting (G==0)“ activated: levels increase or level jumps for receivers/grid points in direction of the road‘s axis CadnaA - Reference Manual 6 177 Chapter 6 - Calculation 6.2.10.2 Nordic Prediction Method (1996) The distance correction in NPM consists of two parts: • the „average distance correction“ DeltaLav according to equation 2.34 and • the correction for „short distance to the road“ DeltaLka according to equation 2.54 (both in /73/). DeltaLka is a function of the (perpendicular) distance a and the road width 2b (see chapter 2.5.7 of /73/). This means that the result depends on the road width entered in CadnaA, even when there is just a single emission line. Distance Correction 6 In CadnaA, both corrections are only applied when the option „Calc outer Lanes separately“ is deactivated (i.e. „strictly NPM“). With the option activated the distance correction is just based on DeltaLav. In both cases, the relevant distance is the perpendicular (!) distance to the road‘s axis and not the distance from the (partial) source to the receiver. As NPM is basically a „long infinite road“ model it requires an angle correction to correct for the finite length of a road section. This angle correction DeltaLalpha (see equation 2.51 /73/) disappears for receiver locations in direction of the road (with =0°). Correction for Angle of View The angle correction does not apply when calculating maximum levels (see /73/, chapter 2.6.3). Provided the option „Calc outer Lanes separately“ is deactivated, both, the two parts stated in NPM for the overall distance correction, may - in conjunction with the angle correction - lead to unexpected level jumps and weird grid contours close to the source. This is immanent to the NPM model and not a CadnaA specific effect. CadnaA - Reference Manual CONCLUSION 178 6 Combined Assessment Road/Railway Chapter 6 - Calculation 6.2.10.2 Nordic Prediction Method (1996) In case of assessments with combined impact by road and railway noise the maximum level of both has to be evaluated according to local legal provisions. In CadnaA, this can be handled within the configuration, „Evaluation Parameters“ tab (see chapter 6.2.5), by using the expression „max(strd, schd)“ for the evaluation type „f(x)“: 6 CadnaA - Reference Manual 6 179 Chapter 6 - Calculation 6.2.10.3 NMPB-Routes 1996 6.2.10.3 NMPB-Routes 1996 6 Dialog Configuration, tab „Road“ for NMPB-Routes 1996 By default, this option is deactivated. In this case, the maximum order of reflection is specified via the „Reflection“ tab (see chapter 6.2.8 "Reflection Tab"). Calc exactly one Reflection Order With this option being activated just 1st order of reflection will be considered. In this case, higher reflections should be accounted for by the multiple reflection correction according to RLS-90 /17/ (see below). When this option is activated the multiple reflection correction is calculated according to RLS-90 (see chapter 2.4.2 "RLS-90"), based on additional input data for each road object. By default, this option is deactivated. The application of both options, „Calc exactly one Reflection Order“ and „Use Multiple Reflection Correction“, may heavily reduce the calculation time as NMPB-method usually requires a higher order of reflection to be selected to obtain realistic levels. CadnaA - Reference Manual Use Multiple Reflection Correction 180 6 Chapter 6 - Calculation 6.2.10.3 NMPB-Routes 1996 6 Extended dialog Road to consider the Correction for Multiple Reflections acc. to RLS-90 (inside red frame) In this case the dialog is extended at the bottom right by an input scheme to enter the required data (for details see chapter 2.4.2 "RLS-90", section "Correction for Multiple Reflections"). Calculate outer Lanes separately By default, the center lines of the outermost lanes of a road are the emission lines (at a height of 0.5 m). When this option is deactivated just the road’s center line represents the emission line. Emission Calculation Three different types of emission spectrum can be selected: • NMPB - Guide de Bruit: This setting applies the emission spectrum as specified by the original guideline /77/ (see chapter 2.4.4). • Mithra: This setting applies the modified emission spectrum as used in the former French software MITHRA which differs from the guideline. • EC-guideline 2003/613/EC: This setting applies the modified emission spectrum (see below) to be used in conjunction with the EC-interim calculation methods /114/. CadnaA - Reference Manual 6 181 Chapter 6 - Calculation 6.2.10.3 NMPB-Routes 1996 The values R(j) of the weighting spectrum to be used in accordance with 2003/613/EC is: i Frequency (Hz) R(j) in dB(A) 1 125 -14,5 2 250 -10,2 3 500 -7,2 4 1000 -3,9 5 2000 -6,4 6 4000 -11,4 Reference Spectrum accord. to 2003/613/EC 6 Via the button „Meteorology“ the percentage of „favorable conditions“ in wind sectors stepped by 20° can be specified for the time periods D/E/N separately. The percentage refers to the assessment interval, usually an entire year. Meteorology For calculations using NMPB 1996 the following items from the list box apply: List Box / Locations • • • • (default): favorable conditions D/E/N = 50/75/100 % (favorable): favorable conditions D/E/N = 100/100/100 % (homogène): favorable conditions D/E/N = 0/0/0 % XXX (1996) with „XXX“ representing a French town and region: data for the percentage of favorable conditions according to NMPB 1996. CadnaA - Reference Manual 182 6 Chapter 6 - Calculation 6.2.10.3 NMPB-Routes 1996 The items XXX (2) and XXX (3) do not apply when using NMPB 1996, but refer to NMPB 2008 instead (see chapter 6.2.10.4). No hint is possible here what percentage may apply to an unknown location when just a general description of the local orography is available. Note 1 - „Favorable conditions“ are such facilitating the propagation of sound (i.e. which are likely to cause a higher sound pressure level at the receiver point). This situation makes use of the (spectral) ground attenuation for downwind propagation conditions as specified in ISO 9613-2 / 8/. Note 2 - The „homogeneous condition“ does not refer to any specific meteorological situation. In fact, the rays are straight lines, not accounting for any atmospheric influence. This kind of meteorological situation has been applied by all former prediction models used in France. 6 Evening Values = Day Values With this option active the daytime values will be applied for the Evening period as well. CadnaA - Reference Manual 6 183 Chapter 6 - Calculation 6.2.10.3 NMPB-Routes 1996 Additional Information NMPB applies a different correction with one screen and with two screens. The correction of ground attenuation for rays above barriers depends on the distance from the source to the first barrier, and from the distance from the last barrier to the receiver. Thus, the obtained results are specific to the NMPB-approach and not due to CadnaA-implementation (see equation (16) in chapter 7.4.4 of NMPB /77/). Diffraction Model The additional road surfaces selectable according to EC-guideline 2003/613/ EC are selectable from the Road dialog, list box “Road Surface“. Additional Road Surfaces see chapter 2.4.4 "NMPB-Routes 1996" The table provides information on combinations of wind speed Ui and temperature Ti corresponding to specific propagation types. The original data is from LRPC of Angers (Laboratoire Régional des Ponts et Chaussées, Angers/France) /78/. In this table, 5 propagation types have been defined: -- very high attenuation due to very rising rays (“Unfavourable” situation) - high attenuation due to rising rays (“Unfavourable” situation) Z null meteorological effects due to linear rays (“Homogeneous” situation) + moderated increase of noise level due to going down rays (“Favourable” situation) ++ high increase of noise level due to going down rays (“Favourable” situation) Impossible meteorological situations are marked by grey cells. CadnaA - Reference Manual Meteorological Situations 6 184 6 Chapter 6 - Calculation 6.2.10.3 NMPB-Routes 1996 The input conditions (Ui; Ti) of the grid fit to the following criteria: 6 U1 strong wind (3 to 5 m/s) contrary to the emitter – receptor sense U2 from light to mean adverse wind (1 to 3 m/s) U3 no wind or traverse wind U4 from light to mean carried wind U5 strong carried wind and T1 day; strong radiation; dry surface; not much wind T2 conditions identical to T1 but one at least is not verified T3 rising or setting down of sun or (windy and cloudy weather; surface not so wet) T4 night and (cloudy or windy) T5 night and clear sky and light wind CadnaA - Reference Manual 6 185 Chapter 6 - Calculation 6.2.10.4 NMPB-Routes 2008 6.2.10.4 NMPB-Routes 2008 6 Dialog Configuration, tab „Road“ for NMPB-Routes 2008 CadnaA displays the edition on which the contemporary implementation is based upon. By default, this option is deactivated. In this case, the maximum order of reflection is specified via the „Reflection“ tab (see chapter 6.2.8 "Reflection Tab"). With this option being activated just 1st order of reflection will be considered. In this case, higher reflections should be accounted for by the multiple reflection correction according to RLS-90 /17/ (see below). CadnaA - Reference Manual Calculation accord. to ... Calc exactly one Reflection Order 186 6 Use Multiple Reflection Correction Chapter 6 - Calculation 6.2.10.4 NMPB-Routes 2008 When this option is activated the multiple reflection correction is calculated according to RLS-90 (see chapter 2.4.2 "RLS-90"), based on additional input data in the edit dialog of each road object. By default, this option is deactivated. 6 The application of both options, „Calc exactly one Reflection Order“ and „Use Multiple Reflection Correction“, may heavily reduce the calculation time as NMPB-method usually requires a higher order of reflection to be selected to obtain realistic levels. In this case the dialog is extended at the bottom right by an input scheme to enter the required data (for details see chapter 2.4.2 "RLS-90", section "Correction for Multiple Reflections"). Calculate outer Lanes separately By default, the center lines of the outermost lanes of a road are the emission lines (at a height of 0.05 m). When this option is deactivated just the road’s center line represents the emission line. Year of Calculation Enter here the actual year of calculation used to correct for the aging of the road surface (for details see chapter 2.4.5 "NMPB-Routes 2008"). Meteorology Via the button „Meteorology“ the percentage of „favorable conditions“ in wind sectors stepped by 20° can be specified for the time periods D/E/N separately. The percentage refers to the assessment interval, usually an entire year. CadnaA - Reference Manual 6 187 Chapter 6 - Calculation 6.2.10.4 NMPB-Routes 2008 For calculations using NMPB 2008 the following items from the list box apply: • • • • (default): favorable conditions D/E/N = 50/75/100% (favorable): favorable conditions D/E/N = 100/100/100% (homogène): favorable conditions D/E/N = 0/0/0% XXX (2) and XXX (3) with „XXX“ representing a French town and region: data of the percentage of favorable conditions for two (2: D, N) or three time periods (3: D, E, N) according to NMPB 2008. The items XXX (1996) do not apply when using NMPB 2008, but refer to NMPB 1996 instead (see chapter 6.2.10.3). NMPB 2008 specifies the following hours for the respective periods: List Box / Locations 6 2 periods: D 6-22 h, N 22-6 h 3 periods; D 6-18 h, E 18-22 h, N 22-6 h When assessing mixed levels (e.g. Lden or Ldn) the respective reference times have still to be defined on tab „Reference Time“ (see chapter 6.2.4). CadnaA does not set those periods automatically based on the type of meteorology item selected from the list box. No hint is possible what percentage may apply to an unknown location when just a general description of the local orography is available. Note 1 - „Favorable conditions“ are such facilitating the propagation of sound (i.e. which are likely to cause a higher sound pressure level at the receiver point). This situation makes use of the (spectral) ground attenuation for downwind propagation conditions as specified in ISO 9613-2 / 8/. Note 2 - The „homogeneous condition“ does not refer to any specific meteorological situation. In fact, the rays are straight lines, not accounting for any atmospheric influence. This kind of meteorological situation has been applied by all former prediction models used in France. With this option active the daytime values will be applied for the Evening period as well. CadnaA - Reference Manual Evening Values = Day Values 188 6 Calc Atalus Chapter 6 - Calculation 6.2.10.4 NMPB-Routes 2008 In NMPB 2008, the attenuation due to the embankment Atalus is part of the attenuation due to the boundary of the propagation medium in downward refraction conditions Afront,F („talus“ is French for „embankment“). This option is activated by default. In this case, Atalus is calculated and included in Afront,F. When deactivated, Atalus is zero. 6 This option is also relevant when applying the „reference DLL“ (see below). Use Ch in Calculation of Abar By the factor Ch the attenuation by „pure diffraction“ is modified for barriers (not for terrain contours). Activating this option may lead to a lower barrier attenuation (for details see /80/). Use reference DLL This option is deactivated by default. In this case, CadnaA code is used for the calculation, implemented based on the printed documentation of NMPB 2008. By activating this option the later released, but officially provided reference DLL (developed by the French consortium) is used for the calculation. This option requires to copy the reference DLL (PropagationNMPB.dll) into the respective CadnaA installation directory. The DLL is not part of the CadnaA installation procedure and is, therefore, distributed separately. CadnaA - Reference Manual 6 189 Chapter 6 - Calculation 6.2.10.5 CNOSSOS-EU 6.2.10.5 CNOSSOS-EU 6 By default, this option is deactivated. In this case, the maximum order of reflection is specified via the „Reflection“ tab (see chapter 6.2.8 "Reflection Tab"). Calc exactly one Reflection Order By default, the center lines of the outermost lanes of a road are the emission lines (at a height of 0.05 m). When this option is deactivated just the road’s center line represents the emission line. Calculate outer Lanes separately By deactivating this option the reference conditions are used (temperature 15 °C, relative humidity 70%). When activated the settings for temperature and relative humidity on the „Industry“ tab apply (see chapter 6.2.9.9). Use Temperature from Industry-Tab Air absorption in CNOSSOS-EU is calculated according to ISO 9613-1 /8/. CadnaA - Reference Manual 190 6 Studded Tyres, Period Ts (months) 6 Chapter 6 - Calculation 6.2.10.5 CNOSSOS-EU Number of months where studded tyres are used (within a single year). In CNOSSOS-EU, the increase in rolling noise emission due to studded tyres is only attributed to the proportion of light vehicles (i.e. class 1, see below). Studded Tyres, Percentage Qstud,ratio (%) This is the average ratio of the total volume of light motor vehicles per hour equipped with studded tyres during the period Ts (in months). Max. Speeds of Vehicle Classes Specification of the maximum speeds for each vehicle class: Class Name Description 1 Light motor vehicles Passenger cars, delivery vans <= 3.5 tons, SUVs, MPVs including trailers and caravans 2 Medium heavy vehicles Medium heavy vehicles, delivery vans > 3.5 tons, buses, motorhomes, etc. with two axles and twin tyre mounting on rear axle 3 Heavy vehicles Heavy duty vehicles, touring cars, buses, with three or more axles 4a Powered two-wheelers Two-, Three- and Four-wheel Mopeds 4b Motorcycles with and without sidecars, Tricycles and Quadricycles In CNOSSOS-EU there are two types of maximum speeds: the maximum legal speed of the vehicle category and the maximum legal speed of the road or a road section (see chapter 2.4.6). In the calculation, the lower of both applies. CadnaA - Reference Manual 6 191 Chapter 6 - Calculation 6.2.10.5 CNOSSOS-EU These default percentage values apply when the road‘s emission is specified as MDTD (with or without use of diurnal patterns), and not by hourly traffic data. In this case, default percentage values for the amount of vehicles of class 3 in the sum of (2+3), and amount of vehicles of class 4b in the sum of (4a+4b) are required. Default Percentages Default values: (2+3)=50, (4a+4b) =50. This button enables to modify the emission parameters for the five CNOSSOS-EU specific vehicle classes. Vehicle Classes 6 With this setting, the parameters specified in CNOSSOS-EU /16/ are used. Default When toggling from option „User-defined“ back to „Default“, the edited values in the table - if any - remain unchanged. Nevertheless, the default values are used in the calculation. This setting enables to edit the following parameters in octave bandwidth: CadnaA - Reference Manual User-defined 192 6 Chapter 6 - Calculation 6.2.10.5 CNOSSOS-EU Parameter 6 Description Ar coefficient Ar for rolling noise Br coefficient Br for rolling noise Ap coefficient Ap for propulsion noise Bp coefficient Bp for propulsion noise Astudded correction coefficient a for studded tyres (for class 1) Bstudded correction coefficient b for studded tyres (for class 1) Cr,signal coefficient for rolling noise at crossings with traffic lights Cr,roundabout coefficient for rolling noise at roundabouts Cp,signal coefficient for propulsion noise at crossings with traffic lights Cp,roundabout coefficient for propulsion noise at roundabouts Ktemperature temperature correction Km Note - The coefficients Cr,signal, Cr,roundabout, Cp,signal and Cp,roundabout are non-spectral in CNOSSOS-EU, but are shown here as a spectrum. In case several user-defined parameter sets are required, each set can be saved and loaded in conjunction with the configuration of calculation (see chapter 6.2.1 "Country Tab"). Copy & Paste buttons These buttons can be used to copy or paste the selected dataset for a vehicle category (including the row and column identifiers) to or from the clipboard. Note that the „Paste“ button will just highlight in case the data stored in the clipboard has the required format. Therefore, copy the existing data using the „Copy“ button, then modify it as required in an external software and copy the entire table back the clipboard. CadnaA - Reference Manual 6 193 Chapter 6 - Calculation 6.2.10.5 CNOSSOS-EU Via the button „Meteorology“ the percentage of „favorable conditions“ in wind sectors stepped by 20° can be specified for the time periods D/E/N separately. The percentage refers to the assessment interval, usually an entire year. Meteorology 6 For further details on this dialog, see chapter 6.2.10.4, section "Meteorology". CadnaA - Reference Manual 194 6 Chapter 6 - Calculation 6.2.10.5 CNOSSOS-EU 6 CadnaA - Reference Manual 6 195 Chapter 6 - Calculation 6.2.10.6 CRTN 6.2.10.6 CRTN 6 Dialog Configuration, tab „Road“ for CRTN Select the evaluation parameter from the list box: • • L10: This option evaluates the L10 level according to CRTN (default setting). Leq acc. to Annex A Method 1 of TRL study: The conversion rules according to method 1 of TRL study are applied (using equations (4.4) and (4.5) of /83/). The conversion is based on the same segmentation rules as being used for L10 calculations. Since the conversion for non-motorways with hourly traffic flows < 200 veh/h and during the period 24:00 to 06:00 hours deviates (see equation (4.5) of /83/) note the following points: A further check-box „Motorway“ is displayed on the dialog Road (see chapter 2.4.7) enabling to distinguish between motorways and nonmotorways. Allocate the period 24:00 to 06:00 hours to the nighttime by typing in 6 letters N (see chapter 6.2.4 "Reference Time Tab"). Note that just the hourly traffic from 24:00 to 06:00 hours having N's is taken (when using diurnal patterns). CadnaA - Reference Manual Calculation 196 6 Use Non Standard Reference Time D/E/N = 12/4/8 6 Chapter 6 - Calculation 6.2.10.6 CRTN • Leq = L10 - 3.0 dB: This approach to evaluate Leq from L10 is used in Australia. In order to apply Annex A Method 3 of TRL study /83/ to noise grids and receivers see chapters 5.3.4 and 11.2.1. When using diurnal patterns the hourly traffic flow considered to calculate the emission is by default restricted to the time interval from 6:00 to 24:00 hours. To apply the daily hours as allocated to the intervals D/E/N on the „Reference Time“ tab this option has to be activated. Example The application of diurnal patterns with this option deactivated (i.e. strictly applying CRTN) is explained in chapter 2.4.7. In this example, the daily intervals D/E/N are set to D from 4 to 18 hours (14 hours), to E from 18 to 22 hours (=4 hours), and to N from 22 to 4 hours (= 6 hours). Dialog Calculation|Configuration, „Reference Time“ tab The following diurnal pattern „patt_01“ is used in this example. Traffic figures are 200 vehicles/h from 0:00 to 6:00 hours, and 1000 vehicles/h from 6:00 to 24:00 hours (with HGV=20% for each hour). CadnaA - Reference Manual Chapter 6 - Calculation 6.2.10.6 CRTN 6 197 6 Diurnal Pattern „patt_01“ The hourly traffic data for periods D/E/N result from (see dialogs below): for D: 12400 veh/14 h = 885.71 veh/h for E: 4000 veh/4 h = 1000 veh/h for N: 2800 veh/6 h = 466.67 veh/h CadnaA - Reference Manual 198 6 Chapter 6 - Calculation 6.2.10.6 CRTN The figure to be entered to normalize to a different total traffic count Q still refers to the traffic counts within the time interval from 6:00 to 24:00 hours (i.e. 18 hours) of the pattern selected. Example 1: diurnal pattern PATT_01 with Q=0 veh/18 h (6-24h) applies full traffic counts as from selected diurnal pattern 6 Example 2: diurnal pattern PATT_01 with Q=9000 veh/18 h (6-24h) applies - in this example - 50% of the traffic counts from the selected diurnal pattern (so, not entering 50% of 19200 veh/24h = 9600 veh/24h CadnaA - Reference Manual 6 199 Chapter 6 - Calculation 6.2.10.6 CRTN Clause 30 of CRTN specifies that for a road segment where the traffic flow is in the range 50<=q<200 veh/h or 1000<=Q<4000 veh/18h and the shortest slant distance d' source-receiver is less than 30 metres a low trafficcorrection shall be applied. The low traffic-correction K is calculated according to chart 12 of CRTN. Use Low TrafficCorrection K In CadnaA, the conditions for q (attributes MT, ME, MN) or Q (attribute DTV) are checked depending on what is selected. The low traffic-correction is applied to all receivers or grid points meeting the conditions. The emission value L10 displayed on the dialog Road, however, does not include the low traffic-correction as the receiver's distance is not available for a road object. In CadnaA, for traffic flows lower than the lower limit the following is applied: • q<50 veh/h: K=K(q=50 veh/h) • Q<1000 veh/18h: K=K(1000 veh/18h) The restriction in CRTN, clause 30, that „otherwise no correction should be applied“ is, therefore, not respected for values q or Q smaller than the respective lower limit. On the other hand, this strategy avoids, for example, the emission level to increase for q=49 veh/h compared with q=50 veh/h when not applying such a strategy. CadnaA - Reference Manual 6 200 6 Reflection via Correction (1.5 dB), NOT via mirror sources 6 Chapter 6 - Calculation 6.2.10.6 CRTN CRTN clause 26.2 specifies that the reflection from buildings or other reflecting objects (e.g. barriers) on the opposite side of the road have to be considered by a correction of 1.5 dB depending on the angle of the reflecting object/s seen from the receiver. The value of 1.5 dB occurs in case the entire length of the road has reflecting buildings (i.e. is the maximum reflection correction). When activating this option this CRTN-specific reflection correction of +1.5 dB is applied. CadnaA considers the sum of angles of reflection in relation to the total segment angle as specified in figure 5 of CRTN. long road with opposite reflecting barrier, reflecting barrier deactivated reflecting barrier activated, calculation of reflections according to CRTN clause 26.2 Note - Level increase is just 1.4 dB due to finite road & barrier length. With this option being deactivated, the increase due to reflections is calculated by mirror sources (as usually with CadnaA). In this case, the settings on „Reflection“ tab apply (e.g. order of reflection etc.). Buildings/barriers should be set to reflective for reflections to be included. CadnaA - Reference Manual Chapter 6 - Calculation 6.2.10.6 CRTN 6 201 6 Reflected rays by a barrier (1st order of reflection) However, the results with this option deactivated are not in line with the specifications of CRTN. Buildings and barriers with an absorption coefficient of less than 0.8 will be accounted for as being reflecting in CRTN calculations where the max. 1.5 dB correction applies. Buildings and barriers with an absorption coefficient larger or equal to 0.8 will be excluded from the 1.5 dB-correction. CadnaA - Reference Manual 202 6 Calc accord. to "Design Manual for Roads and Bridges (DMRB)" 6 Chapter 6 - Calculation 6.2.10.6 CRTN The "Design Manual for Roads and Bridges" (release August 2008 /85/) states the following modifications to CRTN-calculation: • road surface correction editable (attribute DSTRO), • no further increase of ground absorption beyond 600 m distance from the road (Agr=Agr(600 m) for d>600 m), • additional rules whether reflections from opposite facades or barriers occur. With this option activated the DMRB-calculation rules are applied. The option "Reflection via Correction (1.5 dB), NOT via mirror sources" needs to be activated in this case. CadnaA - Reference Manual 6 203 Chapter 6 - Calculation 6.2.10.6 CRTN Additional Information CRTN specifies in clause 26.1 that for calculations of the noise level at a distance of 1 metre in front of a façade a correction of +2.5 dB has to be made. CadnaA does not apply this correction automatically for the time being as this CRTN-specification does not match the normal approach when calculating façade reflections. By default, the façade level at receiver points in front of the façade (e.g. at 0.05 m off the facades plane) does not include reflections at the own buildings surface. This is achieved in CadnaA by setting the "Minimum Distance Receiver-Reflector" to e.g. 1 m (so, larger than the distance of the receiver from the façade). Reflections are calculated when this distance is set to 0 m, when the building is reflective, and when at least the first reflection order has been selected (Configuration dialog, „Reflection“ tab). To apply the correction of 2.5 dB for CRTN-calculation the following conditions have to be fulfilled: • The option "Reflection via Correction …" on the „Road“ tab of the dialog Configuration is activated. • Each receiver intended to consider the CRTN-correction of +2.5 dB has the text-variable FACADE=1 specified on the receivers memo window. CadnaA - Reference Manual Facade Effect 6 204 6 Chapter 6 - Calculation 6.2.10.6 CRTN 6 The building below has got two receivers attached to its facade. Two receivers at building’s facade, left rcvr with correction, right rcvr w/o The receiver on the left has a string variable FACADE=1 defined. The increase of 2.5 dB according to CRTN is considered. The receiver on the right has no text variable defined (or with the text variable being zero, FACADE=0). Thus, the level increase is not added. Grid calculations for EUnoise indices see chapter 5.3.4 "Grid Arithmetic", section "Grid calculations for EU-noise indices with CRTN" Conversion to EU-indices at individual receivers see chapter 11.2.1 "Editing the Result Table", section "Conversion to EUindices at individual receivers with CRTN / TRL" CadnaA - Reference Manual Chapter 6 - Calculation 6.2.10.7 TNM 6.2.10.7 6 205 TNM 6 Dialog Configuration, tab „Road“ for TNM By default, all available settings listed below are deactivated. The emission model of TNM considers - depending on the type of source several emission heights. Activating this option will level down all types of sub-sources to a common height of 0.1 m above road surface. option deactivated: up to 3 sub-sources visible on the vertical grid (at 0.1/1.5/3.66 m) CadnaA - Reference Manual option activated: just a single source height at 0.1 m (for both: Adiv based on 3D-distance) All Emissions at 0.1 m above road surface 206 6 Use 3D-distance for calculation of Adiv Chapter 6 - Calculation 6.2.10.7 TNM In TNM, the geometrical divergence is calculated based on the 2D-path length in xy-plane only. This causes the receiver level not depending on height (i.e. level is not decreasing with receiver height). By activating this option calculated levels will depend on receiver height or height of grid points. 6 option „3D-distance for calculation of Adiv“ deactivated (i.e „strictly accord. to TNM“) Correct bug in Fresnel-zonecalculation option „3D-distance for calculation of Adiv“ activated In TNM 2.5-code a sign error in the calculation of Fresnel zones was discovered altering calculation results reasonably. With this option activated the Fresnel-zone-bug will be corrected for in CadnaA-TNM. In case results shall be compared with results obtained by TNM 2.5 software this option should, however, be deactivated. CadnaA - Reference Manual 6 207 Chapter 6 - Calculation 6.2.10.7 TNM In order to obtain correct results in comparison with the release 2.5 of the TNM software further configuration settings are to be respected. Those are described below. Additional Information Regarding the ground attenuation, the settings (on Calculation| Configuration menu, tab "Ground Absorption") are based on the ground absorption factor G of ISO 9613-2 /8/. For the time being, the following airflow resistivities refer to the ground absorption factor G: Ground Absorption Airflow Resistivity (in rayls) Ground Absorption Factor G (ISO 9613-2) TNM-specific ground type 20000 0 (i.e. reflecting) pavement 1000 0.33 *) 600 0.5 *) 400 0.67 *) 300 1 (i.e. absorbing) lawn 6 *) These ground types are not available in CadnaA for the time being. In addition activate the option „Roads/Parking Lots are reflecting (G==0)“. The latter setting will - in conjunction with the additional width from self-screening (see below) - ensure that the entire road width as considered by TNM is reflecting (and not just the region between the emission lines). Activate on the Calculation|Configuration option „Explicit Edges only“, „DTM“ tab (see chapter 6.2.6 "DTM Digital Terrain Model Tab"). TNM 2.5 software just triangulates between „real“ terrain contours, not using the heights of objects (e.g. roads and barriers with absolute heights). For this reason it is required that the geometry of all objects is imported additionally as terrain contours or heights points, as otherwise they will not influence the resulting terrain shape. CadnaA - Reference Manual DTM: Explicit Edges only 208 6 Self-Screening of Roads Chapter 6 - Calculation 6.2.10.7 TNM Activate for all types of roads the option "Self-Screening" (dialog Road| Geometry) and enter an additional width of 1.83 m (6 feet). 6 Dialog Road:Geometry: self-screening with additional width left/right of 1.83 m Temperature and relative Humidity The general settings for the temperature and the relative humidity in CadnaA match with the default settings in TNM 2.5-software (see menu Calculation|Configuration, tab "Industry"): • • Restrictions Changing the attribute’s values for all roads in a project is achieved conveniently via the dialog Modify Objects|Modify Attribute, for attributes SCCR_AW_L and SCCR_AW_R, respectively. 50% relative humidity temperature 20°C The following features of the TNM-software are not implemented in CadnaA for the time being: • • • no TNM-specific parallel barrier analysis, no accelerating ramps and flow control devices, and no import of TNM-files. CadnaA - Reference Manual Chapter 6 - Calculation 6.2.10.8 Czech Method 6.2.10.8 6 209 Czech Method 6 Dialog Configuration, tab „Road“ for Czech Method (accord. to Liberko) The available configuration settings comply with those for RLS-90 (see chapter 6.2.10.1 "RLS-90"). CadnaA - Reference Manual 210 6 Chapter 6 - Calculation 6.2.10.8 Czech Method 6 CadnaA - Reference Manual 6 211 Chapter 6 - Calculation 6.2.10.9 SonRoad 6.2.10.9 SonRoad 6 Dialog Configuration, tab „Road“ for SonRoad By default, the center lines of the outermost lanes of a road are the emission lines (at a height of 0.5 m). When this option is deactivated just the road’s center line represents the emission line. Calculate outer Lanes separately see chapter 6.2.10.3 "NMPB-Routes 1996", section "Meteorology" Meteorology CadnaA - Reference Manual 212 6 Chapter 6 - Calculation 6.2.10.9 SonRoad 6 CadnaA - Reference Manual Chapter 6 - Calculation 6.2.10.10 HJ 2.4 (2009) 6 213 6.2.10.10 HJ 2.4 (2009) 6 Dialog Configuration, tab „Road“ for HJ 2.4 (2009) By default, the center lines of the outermost lanes of a road are the emission lines (at a height of 0.5 m). When this option is deactivated just the road’s center line represents the emission line. CadnaA - Reference Manual Calculate outer Lanes separately 214 6 Chapter 6 - Calculation 6.2.10.10 HJ 2.4 (2009) 6 CadnaA - Reference Manual Chapter 6 - Calculation 6.2.11 Railroad Tab 6.2.11 6 215 Railroad Tab Information on the calculation options for the following standards or guidelines for industry can be found in the German version of the CadnaA reference manual: ONR 305011 (Austria) DIN 18005 (1987, Germany) Semibel (Switzerland) The subsequent table lists the main characteristics of the propagation models for railroad noise as treated in the chapters explaining the configuration options. A special focus is put to the type of modeling being used for the various attenuating effects in sound propagation. Table „Propagation Models Railroad“ A further table describes the properties of obstacles and special-objects in CadnaA with each propagation model. Table „Obstacles and Special-Objects“ CadnaA - Reference Manual 6 216 6 Chapter 6 - Calculation 6.2.11 Railroad Tab Propagation Models Railroad 6 No Option or Propagation Effect Standard / Guideline 1 calculation using A-weighted levels yes yes yes 2 spectral calculation no yes yes 3 geometrical attenuation (divergence) half sphere (2 r2) with directivity full sphere (4 r2) with directivity full sphere (4 r2) 4 attenuation by air absorption yes (according to VDI 2714) using air absorption accord. to ISO 9613-1 yes (for 15°C, 70% RH) 5 handling of ground reflections not by image sources, but by an algorithm considering ground attenuation and meteorological effects in common (see below) as above algorithmic, not by image sources 6 handling of reflections at obstacles just up to 1st order, higher orders applying a „Correction for multiple Reflections“, optionally: calculation to up 20th order, condition for reflection considers obstacle’s size and absorption coefficient/reflection loss of the reflector as above, by default up to 3rd order (accord. to Sch03 2014) or up to 20th order see Schall 03 (1990) 7 attenuation due to ground effect (ground attenuation) for A-weighted levels (not applying ground factor G) alternative procedure (for Aweighted levels) accord. to ISO 9613-2, deviating calculation procedure for water surfaces complies with spectral ground attenuation model of ISO 9613-2 8 attenuation due to screening (at objects) single and double diffraction based on the path length difference of the direct path via the obstacle, screening effect does not depend on wavelength (as just for A-weighted levels), negative path difference cause no screening REMARK: „acoustical Transparency“ of buildings not available single & double diffraction using path difference, ray across obstacle w/o ground absorp., barrier attenuation depending on wavelength concept of effective height 9 handling of lateral diffraction not considered, in CadnaA optionally available with lateral diffr. (using two lat. paths + direct path) not considered 10 handling of multiple obstacles in ray path based on the path length difference of the direct path across all obstacles („ribbon band method“) in CadnaA: applies „rubber band method“ to calculate path difference using the most efficient screen 11 attenuation due to screening (terrain) screening by terrain not treated explicitly, In CadnaA the algorithm for multiple screening objects is applied. as above as with multiple screens 12 handling of meteorological effects (wind) not treated explicitly (meteorological correction is part of the screening calculation), optional: application of Cmet accord. to ISO 9613-2, with calculations acc. to VBUSch: applies Cmet with C0,D/E/N=2/1/0 dB no not available 13 attenuation due to foliage without screening calculation, but based on the length of the curved ray path (arc of a circle) passing through the foliage (with height h) assuming a radius of 5 km not available available 14 attenuation due to built-up areas not considered, in CadnaA optionally accord. to VDI 2714 not available available Schall 03 (1990) Schall 03 (2014) Nordic (1996) CadnaA - Reference Manual 6 217 Chapter 6 - Calculation 6.2.11 Railroad Tab Standard / Guideline CRN SRM II NMPB-Fer (1996) NMPB-Fer (2008) No FTA/FRA CNOSSOS-EU yes yes see chapter 6.2.10, for NMPB96 yes yes yes 1 no yes (63 to 8000 Hz) as above yes (1/3 octaves, 100 to 5000 Hz) no yes (octaves 63 Hz to 8 kHz, + 31.5 Hz 2 in CadnaA: segmented line source segmented line source (distance & viewing angle) as above point source propagation (4r2) in CadnaA: segmented line source point source propagation (4r2) 3 not considered yes (10°C, 80%), option: ISO 9613-2 as above acc. ISO 9613-1 (for 15°C, 70%) not considered yes (acc. to ISO 9613-1) 4 algorithmic, not by image sources algorithmic, not by image sources as above algorithmic, not by image sources algorithmic, not by image sources algorithmic incl. ground absorp. 5 using a global correction, optional in CadnaA: using image sources using image sources, absorption coeff./ reflection loss of reflector as above no mult. reflect. correction by default, optional in CadnaA using image sources, absorption coeff./ reflection loss of reflector yes 6 empirical correction spectral ground attenuation model applying ground factor G (similar to ISO 9613-2) as above spectral model (for favorable: ISO 96132, for homogeneous specific) using ground factor G, in CadnaA: average height (acc. ISO 9613-2) homogeneous & favorable conditions using ground factor G 7 based on path length difference, negative path difference causes screening concept of effective height as above based on path length difference based on path length difference and source height single & double diffr., includes ground effect, using image source method 8 not considered not considered as above not expressively considered not considered yes, at 2 vert. edges (incl. ground abs.) 9 based on path length difference concept of equivalent screens (instead of multiple diffraction) as above via path length difference see Schall 03 (1990) via path length difference (convex hull) 10 as with multiple screens as with multiple screens (no lateral diffraction) as above as with multiple screens see Schall 03 (1990) see ISO 9613-2 11 not available available using Cm (upper limit 3.5 dB), optional: Cmet acc. to ISO 9613-2 as above using occurrences of homogeneous and favorable propagation conditions not considered for homogeneous & favorable prop. cond., energetic addition 12 not available not available as above not available in CadnaA not available not available 13 not available not available as above not available in CadnaA not available not available 14 CadnaA - Reference Manual 6 218 6 Chapter 6 - Calculation 6.2.11 Railroad Tab Obstacles and Special-Objects 6 No Object Type/ Option Standard / Guideline 1 building single & multiple diffraction using shortest path difference, no lateral diffraction by default, no reflection or by absorption coefficient/reflection loss, no acoustical transparency see Schall 03 (1990) see Schall 03 (1990) 2 cylinder single & multiple diffraction using shortest path difference, no lateral diffraction by default, no reflection or by input of absorption coefficient/reflection loss, reflection up to 1st order see Schall 03 (1990) see Schall 03 (1990) 3 barrier single & multiple diffraction using shortest path difference, no lateral diffraction by default, no reflection or by absorption coefficient/reflection loss see Schall 03 (1990) see Schall 03 (1990) 4 floating barrier no diffraction via the lower edge (screening edge without diffraction), otherwise see barrier see Schall 03 (1990) see Schall 03 (1990) 5 barrier with cantilever cantilever is totally absorbing (no reflection), calculation of the path length difference valid for receivers/grid points outside and below the cantilever, otherwise see barrier see Schall 03 (1990) not available (due to „effective height“ concept) 6 bridge plate diffraction as a horizontal plate only (inclined plate approximated to horiz. plate), screening occurs for sources above the bridge plate (diffraction downwards), no reflection at bridge plate see Schall 03 (1990) see Schall 03 (1990) 7 embankment acts as a double barrier, diffraction for direct path (no lateral diffraction), no absorptive/reflective properties, NOTE: The embankment is not considered in the triangulation! see Schall 03 (1990) see Schall 03 (1990) 8 ground absorption area not relevant (generalized ground attenuation) areas with G=0 assumed to represent water surfaces yes, freq. dependent using ground factor G (as in ISO 9613-2, section 7.3.1) 9 built-up area/ foliage not relevant by default, optionally accord. to VDI 2714 optionally accord. to ISO 9613-2 built-up area by sound dispersion (NPM), foliage: via path length with heff 10 3D-reflector screening based on shortest path difference, two lateral paths, no reflection or by absorption coeff./reflection loss, reflection up to 1st order, no summation of diffraction via multiple edges, no multiple diffraction see Schall 03 (1990) not available (due to „effective height“ concept) 11 self screening additional feature in CadnaA: causes screening effect downwards, additional with left/right available (fixed to the road, screening just for the own road source) see Schall 03 (1990) see Schall 03 (1990) 12 additional width/ parapet L/R parapet left/right available, parapet length can be restricted using station marks, additional width just for ground absorption with no effect with Schall03 see Schall 03 (1990) see Schall 03 (1990) Schall 03 (1990) Schall 03 (2014) Nordic (1996) CadnaA - Reference Manual 6 219 Chapter 6 - Calculation 6.2.11 Railroad Tab Standard / Guideline CRN SRM II No NMPB-Fer (1996) NMPB-Fer (2008) FTA/FRA CNOSSOS-EU see Schall 03 (1990) see Schall 03 (1990) see NMPB-routes (1996), chapter 6.2.10 see Schall 03 (1990) see Schall 03 (1990) see Schall 03 (1990), but for homogeneous & favorable conditions 1 see Schall 03 (1990) see Schall 03 (1990) as above see Schall 03 (1990) see Schall 03 (1990) for homogeneous & favorable conditions 2 see Schall 03 (1990) see Schall 03 (1990) as above see Schall 03 (1990) see Schall 03 (1990) see Schall 03 (1990), but for homog. & favorable cond. 3 see Schall 03 (1990) see Schall 03 (1990) as above see Schall 03 (1990) see Schall 03 (1990) see Schall 03 (1990) 4 available, using path length difference not available (due to „effective height“ concept) as above not available not available (just for vertical barriers) see Schall 03 (1990) 5 see Schall 03 (1990) see Schall 03 (1990) as above see Schall 03 (1990) see Schall 03 (1990) see Schall 03 (1990) 6 see Schall 03 (1990) see Schall 03 (1990) as above see Schall 03 (1990) see Schall 03 (1990) see Schall 03 (1990) 7 empirical ground correction (chart) freq. dependent using ground factor G (see ISO 9613-2, section 7.3.1) as above using ground factor G (for favorable and homogeneous) using ground factor G, averaging with multiple ground absorption areas yes, using ground factor G (for favorable and homogeneous) 8 not available not available as above not available not available in CadnaA (for the time being) no effect 9 see Schall 03 (1990) not available (due to „effective height“ concept) as above not available not available (just for vertical barriers) not available 10 see Schall 03 (1990) see Schall 03 (1990) as above see Schall 03 (1990) see Schall 03 (1990) see Schall 03 (1990) 11 see Schall 03 (1990) see Schall 03 (1990) as above see Schall 03 (1990) see Schall 03 (1990) see Schall 03 (1990) 12 CadnaA - Reference Manual 6 220 6 Chapter 6 - Calculation 6.2.11 Railroad Tab 6 CadnaA - Reference Manual Chapter 6 - Calculation 6.2.11.1 Schall 03 (1990) 6.2.11.1 6 221 Schall 03 (1990) 6 Dialog Configuration, tab „Railroad“ for Schall 03 (1990) (option „strictly according to Schall 03“ deactivated) With this option activated, CadnaA will calculate for railways • • • • • only the first-order reflections, irrespective of the order of reflection specified on the „Reflection“ tab, considering a railway correction of 5 dB, no lateral diffraction at obstacles, no attenuation by built-up areas, and no meteorological correction. All other settings made on the „Reflection“ tab, "Conditions for Calculation of Reflection", such as the search radius for reflecting objects, will apply even when the option „Strictly according to Schall 03/Schall-Transrapid“ is activated (see chapter 6.2.8 "Reflection Tab"). CadnaA - Reference Manual Strictly according to Schall 03 222 6 Chapter 6 - Calculation 6.2.11.1 Schall 03 (1990) Calc exactly one reflection order With this option deactivated the maximum order of reflection is specified via the „Reflection“ tab (see chapter 6.2.8 "Reflection Tab"). No Lateral Diffraction When this option is deactivated the lateral diffraction will be considered which is normally not relevant to the receiver level due to the extension of the railway sources (line sources) in normal situations No Housing Attenuation By default, the attenuation by built-up areas is not considered by Schall 03. When this option is deactivated the CadnaA-object „Built-Up Area“ causes a screening effect. 6 Railway Correction (dB) The housing attenuation DG is calculated accord. to VDI 2714 (see chapter 3.5 "Built-Up Areas and Foliage"). This value is not displayed on the calculation protocol in a separate column (see CadnaA-manual „Attributes, Variables, and Keywords“, chapter "Chapter 6 - Protocol Abbreviations"). Any entered railway correction will be considered upon calculation. Thus, to consider no railway correction a value of 0 dB has to be entered. see also section "Strictly according to Schall 03" No Meteorology (Cmet see Industry) No meteorological correction is established by Schall 03. In CadnaA, nevertheless, the meteorological effect can be considered by deactivation of this option. In this case, the settings on the list box „Meteorology“ on the „Industry“ tab are relevant. The value of Cmet will be calculated according to ISO 9613-2. This value is not displayed on the calculation protocol. see also: chapter 6.2.9.1 "ISO 9613", section "Meteorology" CadnaA - Reference Manual 6 223 Chapter 6 - Calculation 6.2.11.1 Schall 03 (1990) With performing calculations according to END (Environmental Noise Directive /121/), this option has to be activated. In this case, the number of trains (or the emission parameter) during the Evening period is considered as well. The values displayed on the „Reference Time“ tab („D/E/N=12/4/8 h“) will be updated based on the defined time intervals (see chapter 6.2.4 and chapter 6.2.5 "Evaluation Parameters Tab"). Use Non-Standard Reference Time D/E/ N relevant for Germany only! Calculation acc. to VBUSch The German method VBUSch is just relevant in conjunction with evaluations for END /121/. First, deactivate the option „Strictly according to Schall 03“ and activate the option „Calculation acc. To VBUSch“. The main modifications are: • • • The setting for lateral diffraction is not possible any longer. No railway bonus specifiable. Cmet is calculated automatically (C0 (D/E/N)=2/1/0 dB). When not considering Cmet and with the same emission D/E/N a level difference between Lden and Ln of 6.395 dB results. Since Cmet is automatically taken into account in CadnaA, the difference is usually smaller than this value. • • fixed reference Time Day/Evening/Night = 12h/4h/8h The penalty for railway lines with wooden sleepers is 2 dB (instead 0 dB according to Schall 03). For maximum speeds vmax>200 km/h an additional aerodynamic noise source is included at a source height of 4,5 m. • CadnaA - Reference Manual 6 224 6 Self-Screening at Buildings 6 Chapter 6 - Calculation 6.2.11.1 Schall 03 (1990) For calculations according to the German railway guideline Schall 03 the selfscreening of buildings with backside receivers can alternatively be considered or not. This option refers to a requirement stated by Schall 03 (section 7.5) that „at buildings with gaps in between ... just the screening by the first row of buildings, being next to the railway line, shall be considered ...“ (translated from German). To do so, a string variable SCREEN_TEST_ID=1 (on the dialog MemoWindow) is defined for the respective building. With the variable being set it will be checked whether the ID of a receiver corresponds with the building‘s ID. With corresponding IDs the respective building is screening, otherwise not. This option enables to respect the detailed specification of Schall 03, just to consider the screening by the first row of buildings, while for backside facades the self-screening effect shall be included. CadnaA - Reference Manual 6 225 Chapter 6 - Calculation 6.2.11.2 Schall 03 (2014) 6.2.11.2 Schall 03 (2014) 6 Dialog Configuration, „Railway“ tab for Schall03 (2014) Options When enabled, at maximum three orders of reflection are calculated regardless of the order selected on the „Reflection“ tab (see chapter 6.2.8). This setting follows strictly the specifications in Schall03 (2014) /26/ („reflections higher than the 3rd order remain unconsidered...“). Calc exactly three Orders of Reflection When deactivated, the maximum reflection order as set on the „Reflection“ tab set is considered. When activated, all the emission of all sub-sources are set to a source height of 0.0 m above railhead (0.6 m above ground). All Emissions at 0.0m above railhead When this option is deactivated the lateral diffraction will be considered which is normally not relevant to the receiver level due to the extension of the railway sources (line sources) in normal situations. No Lateral Diffraction CadnaA - Reference Manual 226 6 Chapter 6 - Calculation 6.2.11.2 Schall 03 (2014) Ground with G=0.00 represents Water in Eq. 16 When activated all ground absorption areas having a ground factor G=0.00 are considered as water surfaces and their damping Agr,w is calculated according to equation 16 in /26/. Use Non-Standard Reference Time D/E/N With this option deactivated the following time interval lengths will be considered: Day (D)=16 hours, Night (N)=8 hours. When this option is activated, however, the time intervals and penalties on the „Reference Time“ tab (see chapter 6.2.4) are taken into account. This option has to be activated for calculations according to END (Environmental Noise Directive /121/) in order to consider the number of trains (or the emission parameter) during the Evening period as well. 6 The values displayed here are updated based on the defined time intervals D/E/N on the „Reference Time“ tab. Railway Correction (dB) Any entered railway correction will be considered upon calculation. Thus, to consider no railway correction a value of 0 dB has to be entered. Determine Raster Factor iteratively According to Schall03 (2014) is has to be checked during segmentation of the railway tracks whether th receiver level/s change by less than 0.1 dB when halving all sections. If the change is larger, the halved section length has to be used. When enabled, this condition is checked iteratively for all receivers (but not for building evaluations and grid points) until the condition is met. Consequently, at least three steps of processing runs are required to check this condition referring to the source‘s segmentation. CadnaA - Reference Manual 6 227 Chapter 6 - Calculation 6.2.11.2 Schall 03 (2014) Additional Information When calculating Abar according to equation (19) in /26/ the term Drefl representing the Calculation of Abar „level correction for reflecting noise barriers at a distance ds <= 5 m with an absorbent base with height habs above the railhead“ (translation from German) is automatically considered by CadnaA. This requires that two barrier objects are used to model this situation: one modeling the absorbent base and - when looking from the source side - a second one modeling the reflecting barrier behind it. In order to distinguish whether a barrier has to be regarded as absorbing or reflecting the following criteria apply: • Absorption Coefficient Alpha < 0.2: „reflecting“ • Absorption Coefficient Alpha > 0.6: „absorbing“ CadnaA - Reference Manual 6 228 6 Chapter 6 - Calculation 6.2.11.2 Schall 03 (2014) 6 CadnaA - Reference Manual 6 229 Chapter 6 - Calculation 6.2.11.3 Nordic Prediction Method (1996) 6.2.11.3 Nordic Prediction Method (1996) 6 Dialog Configuration, tab „Railroad“ for Nordic Prediction Method (1996) With this option deactivate the maximum order of reflection is specified via the „Reflection“ tab (see chapter 6.2.8 "Reflection Tab"). Calc exactly one reflection order Any entered railway correction will be considered upon calculation. Thus, to consider no railway correction a value of 0 dB has to be entered. Railway Correction (dB) The A-weighted maximum levels LAFmax and LmaxF are additional descriptors for railway noise in Nordic Prediction Method /72/. The different corrections are calculated in complete analogy with those of the A-weighted equivalent continuous sound pressure level LA,eq, but a different emission parameter is used (see chapter 2.6.4 "Nordic Prediction Method 1996"). Calc maximum PassBy-Level Besides the emission level, the propagation models for Leq and Lmax calculations differ as well. CadnaA - Reference Manual 230 6 Option LmaxM/LmaxF Chapter 6 - Calculation 6.2.11.3 Nordic Prediction Method (1996) In CadnaA, the two A-weighted maximum sound pressure levels, LmaxM (energy average over train length) or LmaxF (highest level with weighting „Fast“) can be calculated (see chapter 2.6.4). The option „Diesel“ has to be set accordingly for each railway group/ train class on the dialog Library: Train Class (see chapter 2.6.12 "Train Class Libraries", section "Application Nordic Prediction Method"). In order to calculate maximum levels, CadnaA moves a line source for each train class in the train classes list of the railway object. This line source has the sound power level and length as specified in the list. This source is moved according to its speed and specified sampling interval (see below). The maximum level for this line source for each position with the specified sound power level and length is calculated. 6 Sampling Interval (s) In order to determine the highest level, CadnaA shifts the source along the road in steps based on the sampling interval (in seconds). The default value for the sampling interval is 0.1 seconds. Consequently, the resulting distance difference between two source positions is: s v tsampling 1000 3600 where s: distance steps (m) v: speed (km/h), as entered on dialog Railway t: sampling interval (s) Displaying rays (see chapter 5.1) and the calculation protocol (see chapter 6.5) do not make sense with maximum levels as the radiating points are defined by the sampling time. The rays coming from points outside result from the calculation procedure (in case the option „Extrapolate trains to 1/2 length on both sides of rail“ is activated, see below). CadnaA - Reference Manual Chapter 6 - Calculation 6.2.11.3 Nordic Prediction Method (1996) By default, this option is activated. In this case, when calculating the maximum pass-by level, the length of each train class on the track is extrapolated by half of its length beyond the first and the last point of the drawn railway object to cope with segmented railways (e.g. due to different maximum speeds). By deactivating this option, the train length will not be extrapolated beyond the first and the last point of the railway object. Deactivating this option may cause a substantial level decrease for receivers/grid points near the end of the rail source and at curves (see example below). option activated option deactivated For a receiver in the center region of the rail source the levels do not differ. option activated option deactivated For a receiver near the end of the rail source the resulting levels may differ substantially. CadnaA - Reference Manual 6 231 Option „Extrapolate trains to 1/2 length on both sides of rail“ 6 232 6 Chapter 6 - Calculation 6.2.11.3 Nordic Prediction Method (1996) Instead, with the option deactivated, each railway object could be extended manually to overlap with the next railway object making up the railway track. However, this would require a separate railway object for each train class in order to extend the source line properly with respect to the train length of each class. Other Properties: See Industry This hint refers to the following settings on the „Industry“ tab: Use Non-Standard Reference Time D/E/ N With this option activated the time intervals and penalties on „Reference Time“ tab are applied in the calculation. 6 • • • lateral diffraction if distance smaller temperature/relative humidity As the specification of emission of NPM is based on the traffic data within 24 hours, the values have to be corrected when using daily periods D/E/N with END-calculations /121/. The correction for each octave band is: L 'wo , D / E / N L 'wo 10 lg tD / E / N dB 24 where L’w0, D/E/N: octave band emission level in period D/E/N of length tD/E/N (in hours) L’w0: octave band emission level for 24 hours Example For a daily period D of 12 hours the following correction applies: L 'wo , D L 'wo 10 lg 12 dB L 'wo 3 dB 24 The values displayed on the „Reference Time“ tab (D/E/N=12/4/8 h) will be updated based on the defined time periods DEN. Further Information Combined Assessment Road/Railway see chapter 6.2.10.2, section "Further Information" CadnaA - Reference Manual 6 233 Chapter 6 - Calculation 6.2.11.4 CRN 6.2.11.4 CRN 6 Dialog Configuration, tab „Railroad“ for CRN When the option „Use Non-Standard Reference Time“ is activated the time intervals and penalties on the „Reference Time“ tab are taken into account in the calculation. Railway noise - according to the majority of standards/guidelines - is calculated just for two daily periods: day and night. When doing calculations with respect to END (Environmental Noise Directive /121/), however, this option has to be activated to consider the number of trains (or the emission parameter) during the Evening period as well. see also: chapter 6.2.4 "Reference Time Tab" chapter 6.2.5 "Evaluation Parameters Tab" The values displayed on the „Reference Time“ tab (D/E/N=12/4/8 h) will be updated based on the defined time intervals (hours Day/ Evening/Night). CadnaA - Reference Manual Use Non-Standard Reference Time 234 6 Reflection via Correction (1.5 dB), NOT via mirror sources Chapter 6 - Calculation 6.2.11.4 CRN CRN clause 31.2 /82/ specifies that the reflection from buildings or other reflecting objects (e.g. barriers) on the opposite side of the road have to be considered by a correction of 1.5 dB depending on the angle of the reflecting object/s seen from the receiver. The value of 1.5 dB occurs in case the entire length of the road has reflecting buildings (i.e. is the maximum reflection correction). For more details and examples see chapter 6.2.10.6 "CRTN", section "Reflection via Correction (1.5 dB), NOT via mirror sources". 6 Additional Information Facade Effect CRN specifies in clause 31.1 that for calculations of the noise level at a distance of 1 metre in front of a façade a correction of +2.5 dB has to be made. CadnaA does not apply this correction automatically for the time being as this CRN-specification do not match the normal approach when calculating façade reflections. for more details and examples see chapter 6.2.10.6 "CRTN", section "Facade Effect" Screening Effect In CRN, negative path differences cause screening (see chart 6a in /82/). This means that a substantial screening correction may result with small path differences z (0<z<0.4 m) in situations where the ray is not intersecting with an obstacle, but just passing above its top edge („illuminated zone“). CadnaA - Reference Manual Chapter 6 - Calculation 6.2.11.5 SRM II 6.2.11.5 6 235 SRM II The implementation follows the procedures as defined by the EU-Interim Report /2/ and the EC-Recommendation L 212/49 /107/. Both refer to edition 1996 of the „Reken- en Meetvoorschriften Railverkeerslawaai '96“ / 81/ and not to more recent editions. 6 Dialog Configuration, tab „Railroad“ for SRM II All emission sources are placed at 0.5 m above the railhead instead of applying the sub-source heights as defined in the train class. option deactivated (for train classes C9 and C9r only) CadnaA - Reference Manual option activated All Emissions at 0.5 m above railhead 236 6 Chapter 6 - Calculation 6.2.11.5 SRM II Railway Correction (dB) Any entered railway correction will be considered upon calculation. Thus, to consider no railway correction a value of 0 dB has to be entered. Use Non-Standard Reference Time D/E/N = 12/4/8 With the option „Use Non-Standard Reference Time“ deactivated the following time interval lengths will be considered: Day (D)=16 hours, Night (N)=8 hours. When this option is activated the time intervals and penalties on the „Reference Time“ tab (see chapter 6.2.4) are taken into account. This option has to be activated for calculations according to END (Environmental Noise Directive /121/) in order to consider the number of trains (or the emission parameter) during the Evening period as well. 6 The values displayed here are updated based on the defined time intervals DEN on the „Reference Time“ tab. Air Absorption accord. to ISO 9613-1 In SRM II the air attenuation is based on spectral data at a temperature of 10°C and a relative humidity of 80%. In CadnaA, with activating this option the air absorption can, alternatively, be calculated according to ISO 9613-1 / 8/. Meteorological Correction Cmet acc. to ISO 9613-2 SRM II defines a meteorological correction term CM. The equations used to determine CM are identical to the equations used in ISO 9613-2 to determine Cmet. However, instead of the variable C0 an upper limit of 3.5 dB is used. In order to calculate long-term levels this option enables to replace the 3.5 dB by C0 and using the calculation procedure for Cmet as established by ISO 9613-2 /8/. Other Properties: See Industry This hint refers to the settings on the „Industry“ tab: • • • lateral diffraction if distance smaller temperature/relative humidity CadnaA - Reference Manual 6 237 Chapter 6 - Calculation 6.2.11.6 NMPB-Fer 1996 6.2.11.6 NMPB-Fer 1996 6 Dialog Configuration, tab „Railroad“ for NMPB-Fer 1996 With the option „Use Non-Standard Reference Time“ deactivated the following time interval lengths will be considered: Day (D)=16 hours, Night (N)=8 hours. When this option is activated the time intervals and penalties on the „Reference Time“ tab (see chapter 6.2.4) are taken into account. Use Non-Standard Reference Time D/E/ N This option has to be activated for calculations according to END (Environmental Noise Directive /121/) in order to consider the number of trains (or the emission parameter) during the Evening period as well. The values displayed here are updated based on the defined time intervals DEN on the „Reference Time“ tab. The emission model of NMPB-Fer considers two emission heights. Activating this option will put all emission to a common height of 0.8 m above railhead. All Emissions at 0.8m above railhead (no source at 0.05m) Via the button „Meteorology“ the percentage of „favorable conditions“ in wind sectors stepped by 20° can be specified for the time periods D/E/N separately. The percentage refers to the assessment interval, usually an entire year. Meteorology CadnaA - Reference Manual 238 6 Chapter 6 - Calculation 6.2.11.6 NMPB-Fer 1996 Note 1 - „Favorable conditions“ are such which facilitates the propagation of sound (i.e. which are likely to cause a higher sound pressure level at the receiver point than with a moderate situation). This situation makes use of the (spectral) ground attenuation for moderate downwind as specified by ISO 9613-2 /8/. Note 2 - By the condition „homogène“ the contrary is assumed, the propagation situation is now neither downwind, nor moderate. The rays are straight lines, not accounting for any atmospheric influence. This kind of meteorological situation has been applied by all former prediction models used in France. 6 Evening Values = Day Values With this option active the daytime values will be applied for the Evening period as well. List Box Locations The list box offers a variety of predefined locations (within France) combined with respective data for the percentage of favorable conditions. For more details see chapter 6.2.10.3, section "List Box / Locations". No hint is possible here what percentage may apply to an unknown location when just having a general description of the local orography. CadnaA - Reference Manual Chapter 6 - Calculation 6.2.11.7 NMPB-Fer 2008 6.2.11.7 6 239 NMPB-Fer 2008 6 Dialog Configuration, tab „Railroad“ for NMPB-Fer 2008 With the option „Use Non-Standard Reference Time“ deactivated the following time interval lengths will be considered: Day (D)=16 hours, Night (N)=8 hours. When this option is activated the time intervals and penalties on the „Reference Time“ tab (see chapter 6.2.4) are taken into account. Use Non-Standard Reference Time D/E/ N This option has to be activated for calculations according to END (Environmental Noise Directive /121/) in order to consider the number of trains (or the emission parameter) during the Evening period as well. The values displayed here are updated based on the defined time intervals DEN on the „Reference Time“ tab. The emission model of NMPB-Fer 2008 considers multiple emission heights. Activating this option will put all emission to a common height of 0.0 m above railhead. CadnaA - Reference Manual All Emissions at 0.0m above railhead 240 6 Meteorology Chapter 6 - Calculation 6.2.11.7 NMPB-Fer 2008 Via the button „Meteorology“ the percentage of „favorable conditions“ in wind sectors stepped by 20° can be specified for the time periods D/E/N separately. The percentage refers to the assessment interval, usually an entire year. Note 1 - „Favorable conditions“ are such which facilitates the propagation of sound (i.e. which are likely to cause a higher sound pressure level at the receiver point than with a moderate situation). This situation makes use of the (spectral) ground attenuation for moderate downwind as specified by ISO 9613-2 /8/. Note 2 - By the condition „homogène“ the contrary is assumed, the propagation situation is now neither downwind, nor moderate. The rays are straight lines, not accounting for any atmospheric influence. This kind of meteorological situation has been applied by all former prediction models used in France. 6 Evening Values = Day Values With this option active the daytime values will be applied for the Evening period as well. List Box Locations The list box offers a variety of predefined locations (within France) combined with respective data for the percentage of favorable conditions. For more details see chapter 6.2.10.4, section "List Box / Locations". No hint is possible here what percentage may apply to an unknown location when just having a general description of the local orography. CadnaA - Reference Manual 6 241 Chapter 6 - Calculation 6.2.11.7 NMPB-Fer 2008 see chapter 6.2.10.4, section "Calc Atalus" Calc Atalus By the factor Ch the attenuation by „pure diffraction“ is modified for barriers (not for terrain contours). Activating this option may lead to a lower barrier attenuation (for details see /80/). Use Ch in Calculation of Abar see chapter 6.2.10.4, section "Use reference DLL" Use reference DLL Specify the number of screen-body-interactions to be considered in the calculation. Consider that a single interaction means two reflections, one at the screen and the other at the train‘s body. Number of ScreenBody-Interactions CadnaA - Reference Manual 6 242 6 Chapter 6 - Calculation 6.2.11.7 NMPB-Fer 2008 6 CadnaA - Reference Manual Chapter 6 - Calculation 6.2.11.8 CNOSSOS-EU 6.2.11.8 6 243 CNOSSOS-EU 6 With this option deactivated the following time interval lengths will be considered: Day (D)=16 hours, Night (N)=8 hours. When this option is activated the time intervals and penalties on the „Reference Time“ tab (see chapter 6.2.4) are taken into account. Use Non-Standard Reference Time D/E/ N This option has to be activated for calculations according to END (Environmental Noise Directive /121/) in order to consider the number of trains (or the emission parameter) during the Evening period as well. The values displayed here are updated based on the defined time intervals DEN on the „Reference Time“ tab. The emission model according to CNOSSOS-EU considers multiple emission heights. Activating this option will put all emission to a common height of 0.5 m above railhead. CadnaA - Reference Manual All Emissions at 0.5m above railhead 244 6 Meteorology Chapter 6 - Calculation 6.2.11.8 CNOSSOS-EU Via the button „Meteorology“ the percentage of „favorable conditions“ in wind sectors stepped by 20° can be specified for the time periods D/E/N separately. The percentage refers to the assessment interval, usually an entire year. 6 For further details on this dialog, see chapter 6.2.10.4, section "Meteorology". CadnaA - Reference Manual Chapter 6 - Calculation 6.2.11.9 FTA/FRA 6.2.11.9 6 245 FTA/FRA 6 Dialog Configuration, tab „Railroad“ for FTA/FRA All emission sources are placed at 0.3 m above the railhead instead of applying the sub-source heights as defined in the train class. Consequently, also the sub-source height at 0.05 m is not used. Consider that the default height of the object Railway is 0.6 m which requires to be changed to a height of 0.0 m to meet the FTA/FRA specifications. In case this option is deactivated time intervals Day (D)=15 hours, Evening (E)=0 hours, and Night (N)=9 hours will be considered. With this option activated the allocation of hours as specified on the „Reference Time“ tab will be used instead. All Emissions at 0.0 m above railhead The values displayed here are updated based on the defined time intervals DEN on the „Reference Time“ tab. CadnaA - Reference Manual Use non-Standard Reference Time D/E/ N 246 6 Railway Correction Chapter 6 - Calculation 6.2.11.9 FTA/FRA This option enables to address a general correction or penalty for the receiver level: SPLwith corr = SPLw/o corr - (Railway Correction) In order to apply no railway correction a value of 0 dB has to be entered. Calc maximum PassBy-Level The calculation of the maximum pass-by-level is not covered by FTA/FRA calculation procedures. Nevertheless, CadnaA offers to calculate this maximum level by iteration based on the Leq-based emission. The same propagation model as with Leq calculations according to FTA/FRA is used. To this end, each train class with its corresponding length is moved along the object „Railway“ according to its speed and sampling time (see below). The maximum level for this line source for each position with the specified sound power level and length is calculated. Sampling Interval (s) In order to determine the highest level, CadnaA shifts the source along the railway in steps based on the sampling interval (in seconds). The default value for the sampling interval is 1 second. Option „Extrapolate trains to 1/2 length on both sides of rail“ By default, this option is activated. In this case, when calculating the maximum pass-by level, the length of each train class on the track is extrapolated by half of its length beyond the first and the last point of the drawn railway object. 6 By deactivating this option, the train length will not be extrapolated beyond the first and the last point of the railway object. Deactivating this option may cause a substantial level decrease for receivers/grid points near the end of the rail source and at curves (see example below). For illustration of this effect see chapter 6.2.11.3. CadnaA - Reference Manual 6 247 Chapter 6 - Calculation 6.2.11.9 FTA/FRA Additional Information According to the FRA/FTA-reports, the ground factor G for barrier attenuation is calculated from the effective height Heff (see figure 5-3 of the FRA-report /92/ or figure 6-5 of the FTA-report /91/). As this simplified concept does not work properly in complex situations CadnaA does not apply this computation scheme. Barrier Attenuation In contrary, the ground factor G for barrier attenuation is calculated using the mean height concept of ISO 9613-2 /8/ resulting in a smooth value of Aground even with complex terrain structures in conjunction with multiple obstacles in the ray's path (see ISO 9613-2, section 7.3, for details). 6 The barrier insertion loss Ashielding is based on the equations in table 5-1, page 5-14 of the FRA-report /92/. For source types LOCO and CAR the barrier insertion loss is calculated using the equations for "propulsion sub-sources" (type PROP). The ground attenuation Aground for the sub-sources wheel-rail and propulsion is calculated using the equations on page 5-16 of the FRA-report /92/. For source types LOCO and CAR the equations for "propulsion sub-sources" (type PROP) are applied. Aerodynamic sub-sources receive no ground attenuation at all. Ground Attenuation The excess shielding (as of table 5-5, page 5-18, FRA-report /92/) by rows of buildings (in CadnaA called "built-up areas") and by dense tree zones (in CadnaA called "foliage") are not considered - for the time being. Excess Shielding CadnaA - Reference Manual 248 6 Chapter 6 - Calculation 6.2.11.9 FTA/FRA 6 CadnaA - Reference Manual Chapter 6 - Calculation 6.2.12 Aircraft Tab 6.2.12 6 249 Aircraft Tab This tab is only relevant in conjunction with the CadnaA option FLG . See the specific manual on „Aircraft Noise Calculation“. 6 CadnaA - Reference Manual 250 6 Chapter 6 - Calculation 6.2.12 Aircraft Tab 6 CadnaA - Reference Manual 6 251 Chapter 6 - Calculation 6.2.13 Optimizable Source Tab 6.2.13 Optimizable Source Tab This tab is only available when having the option BPL installed. 6 On tab „Opt.Src.“ three different options referring to the propagation conditions applied in conjunction with optimizable sources (see chapter 2.9) can be specified. • With this option, the calculation of propagation of optimizable sources apply the selected industry standard or guideline (see dialog Calculation|Configuration, „Country“ tab, see chapter 6.2.1). like Industry Sources • With this option, the propagation just considers geometrical divergence in a free-field using: Free field (4*pi*r²) SPL = PWL - 11 dB - 20 lg r In this case, there are no other damping effects, like air absorption and diffraction, considered. • With this option, the propagation just considers geometrical divergence in a semi-free-field using: SPL = PWL - 8 dB - 20 lg r CadnaA - Reference Manual Free field (2*pi*r²) 252 6 Chapter 6 - Calculation 6.2.13 Optimizable Source Tab Again, there are no other damping effects considered. option „r is horizontal (2D) distance“: With this option activated the 2D-distance as projected to the xy plane is used to calculate the geometrical divergence. This setting complies with the requirement of DIN 45691 /34/. Mixed parameters in conjunction with option BPL Please note that the optimization of sound power levels per m² using the option BPL can be carried out only for the daytime level Ld and the night-time level Ln (list box „Day/Night“ on the dialog Optimizable Source). In particular, the optimization of mixed evaluation parameters (like Lde or Lden) is excluded - for the time being. Editing Iteration Increment By default, the iteration increment applied with optimizable sources sources is 0.1 dB. 6 In order to optimize for the calculation runtime, particular at a large number of BPL sources, the iteration increment can be set using a local text block (see chapter 12.5, named BPL). Example Name: BPL Text: DELTA_L = 1.0 In this case, an iteration increment of 1.0 dB will be used when optimizing BPL sources. CadnaA - Reference Manual 6 253 Chapter 6 - Calculation 6.3 Adjustment of the Configuration 6.3 Adjustment of the Configuration Starting from the CadnaA release 4.6.153 the previous configuration options • „Special Reference Time for Industry (min)“ on the „Reference Time“ tab) and • „Compatibility Mode for Industry“ on the „Evaluation Parameters“ are no longer available. These changes are caused by the implementation of diurnal patterns for industrial sources (see chapter 2.1.1, section "Addressing Diurnal Patterns" and chapter 12.3). 6 When loading files saved with previous releases of CadnaA an automatic adjustment of the configuration settings occurs in order to ensure that - even after dropping these options - the same calculation results are obtained. Below some examples for typical configuration adjustments are explained: • case 1: file with industrial sources only and the compatibility mode activated Message Remarks The option "Compatibility mode for Industry" is disabled and the evaluation parameters are changed to: 1: Ld --> Lde The evaluation parameter can be changed directly from Ld to Lde. The "Special Reference Time for Industry (min)" with Day: 780.00 min, Evening: 180.00 min, Night: 60.00 min will be transferred to the Allocation Hour - Periods (on "Ref.Time" tab) by: 13 h D, 3 h E, 1 h N The transfer of the special reference time for industry to the allocation HoursPeriods is directly possible. CadnaA - Reference Manual Examples 254 6 Chapter 6 - Calculation 6.3 Adjustment of the Configuration • case 2: file with industrial sources only and the compatibility mode NOT activated Message Remarks no message regarding "Compatibility mode for Industry" displayed as not used (e.g. with eval. parameters 1: Lde, 2: Ln set) The "Special Reference Time for Industry (min)" with Day: 780.00 min, Evening: 180.00 min, Night: 60.00 min will be transferred to the Allocation Hour - Periods (on "Ref.Time" tab) by: 13 h D, 3 h E, 1 h N 6 • - see case 1 case 3: file with industrial and other source types and the compatibility mode activated, while the option „Use Non-Standard Reference Time D/ E/N“ (for railway and/or aircraft noise) is activated Message Remarks The option "Compatibility mode for Industry" is disabled and the evaluation parameters are changed to: 1: Ld --> (indde++strd++ schd++spod++flgd) The new evaluation parameter 1 is represented by the energetic summation of all source types (with Lde for industry (indde, Day/Evening mixed level) and sports tennis source Day (spod). This representation is required as esp. for roads and railways the Ld was calculated as daytime level, while for industrial sources, however, the Lde was calculated. The "Special Reference Time for Industry (min)" with Day: 780.00 min, Evening: 180.00 min, Night: 60.00 min will be transferred to the Allocation Hour - Periods (on "Ref.Time" tab) by: 13 h D, 3 h E, 8 h N A warning message is displayed, as for rail or aircraft noise the option "Use Non-Standard Reference Time D/E/N" was activated. This causes that the entered special reference times for industry can not be modified in a compatible way without altering the settings for railway during nighttime. NOTE - This incompatibility, however, existed in the old file already and, therefore, the problem is not due to the modification of the configuration. WARNING: Special Reference Time is not compatible with "normal" reference time! CadnaA - Reference Manual Chapter 6 - Calculation 6.3 Adjustment of the Configuration • 6 255 case 4: file with industrial and other source types and the compatibility mode activated, while the option „Use Non-Standard Reference Time D/ E/N“ (for railway and/or aircraft noise) is NOT activated Message Remarks The option "Compatibility mode for Industry" is disabled and the evaluation parameters are changed to: 1: Ld --> (indde++strd++schd++spod++flgd) see case 3 The "Special Reference Time for Industry (min)" with Day: 780.00 min, Evening: 180.00 min, Night: 60.00 min No warning is displayed because the option "Use Non-Standard Reference Time D/E/N" was not activated. This means that the allocation of hours is not relevant for source types Railroad and Aircraft. It is used: D: 16 h, N: 8 h. will be transferred to the Allocation Hour - Periods (on "Ref.Time" tab) by: 13 h D, 3 h E, 1h N CadnaA - Reference Manual 6 256 6 Chapter 6 - Calculation 6.3 Adjustment of the Configuration 6 CadnaA - Reference Manual 6 257 Chapter 6 - Calculation 6.4 Selecting Data for the Calculation 6.4 Selecting Data for the Calculation For a partial calculation, deactivate existing objects. Various tools, which may be combined, are available for this purpose which are described below. Objects can be included or excluded from the calculation by • • • activating/deactivating individual objects via the ID-code on the object’s edit dialog (see manual "Introduction to CadnaA") or by using groups (see chapter 14.3) or by using variants (see chapter 14.2). Exclude Objects for the calculation 6 Deactivated objects are displayed by default with dashed lines. This can be changed on dialog Options|Appearance (see chapter 9.5). By the object „Calculation Area“ an area can be defined being used for the grid calculation (see chapter 5.3). Several calculation areas can be defined in a project file. If no calculation area has been defined the entire limits are used when calculating the grid (see chapter 9.1). Calculation Area With the option „Exclude Area“ on dialog Calculation Area it is possible to exclude a calculation area laying inside the existing calculation area. Inside this area the grid is not calculated. Exclude Area All calculation areas are listed on menu Tables|Other Objects|Calculation Area. The sequence of the data sets determines the sequence of calculation. Table Calculation Area For these calculation areas, CadnaA will take into account all objects, even outside the calculation area, unless they are deactivated. CadnaA - Reference Manual 258 6 Calculation Time Chapter 6 - Calculation 6.4 Selecting Data for the Calculation The total area of all calculation areas in a project file determines the time required for the calculation. It is therefore advisable, for the first test, to specify a large spacing between the receiver points via menu Grid| Properties, in order to watch the progress of the calculation once it has been started and, if required, to abort the calculation and restart it with a different spacing between the receiver points. 6 The level distribution was calculated for this calculation area with all objects within the limits. Calculate Grid The calculation for a calculation area is started via the menu Grid|Calculate Grid (see chapter 5.3.3). If several calculation areas exist, these are calculated one after the other. see also Check Consistency Chapter 5.1.1. CadnaA - Reference Manual 6 259 Chapter 6 - Calculation 6.5 Calculation Protocol 6.5 Calculation Protocol The calculation protocol (Calculation|Protocol dialog) for receiver points is generated during runtime and requires, therefore, to recalculate the levels at receivers after activating this option (via the symbol on the toolbar). 6 The calculation protocol shows the relevant sound power levels (Lw resp. L‘w), the attenuations, and the receiver levels (Lr) for each ray path for the time periods Day, Evening and/or Night. Note that there no protocol exists for mixed receiver levels (e.g Lde or Lden). These mixed levels are calculated from the levels Ld, Le and Ln afterwards (including the entered penalties, if any). Dialog Options With the option „Write Protocol“ activated all intermediate results calculated at receivers (see chapter 5.1) are written to a protocol file upon recalculation. CadnaA - Reference Manual Option „Write Protocol“ 260 6 Protocol File Chapter 6 - Calculation 6.5 Calculation Protocol By default, the filename <cadnaafilename>.cnaprot is used. First, save the CadnaA file to a directory in order to specify the path to write the protocol file to. Use the „Select“ button you may specify an alternative filename and file path. Button „Print“ By clicking the „Print“ button in the Print|Protocol dialog is opened enabling to specify the printer settings and the page layout (check for the analogous options in the Print Report dialog, see chapter 13.2.1). On the „Print Range“ all receiver points are listed and can be selected individually by activating the option „Selected Paragraphs“. Furthermore, the configuration settings can be printed as well. 6 • Use the „Preview“ button to display the selected paragraphs on the CadnaA Print Preview dialog (see chapter 13.2.3). • Clicking the „Print“ button will start to print via the selected printer immediately. Regarding the protocol abbreviations used in the protocol see the manual „Attributes, Variables, and Keywords“, chapter . Button „Export“ Clicking the „Export“ button enables to export the protocol file in ASCII text format. To this end, after the calculation at receivers, specify a filename and select a directory. By clicking „Save“ the protocol file is exported using the currently set table columns. The exported file can be opened with a text editor and be edit, if necessary. CadnaA - Reference Manual 6 261 Chapter 6 - Calculation 6.5 Calculation Protocol Options see below, option „Tables“ Button „Tables“ The selected time range determines whether the protocol is shown for all days periods D/E/N or just for a specific period. Period By default, the option „(all)“ is selected. In this case, the protocol file lists separate rows for each time period D/E/N, provided the emission differs within each of the periods. When the emission is equal within all periods D/ E/N, however, just a single protocol row using the identifier „DEN“ is displayed. 6 Examples: see next page By activating this option the protocol will just list those partial levels which are larger or equal to the entered value. Otherwise, these protocol lines will be suppressed. This option is deactivated by default. Option „Minimum Value for Lr“ Example: By specifying a minimum value of 0.0 dB no negative partial level will be displayed. With this option activated, not the entire calculation for each frequency band will be logged. Instead, the levels are calculated applying the A-weighting to frequency-dependent attenuation terms. When having multiple instances of CadnaA running with all instances writing to same the protocol file assignment problems may occur (e.g. <cadnaafilename>.cnaprot). Make sure that the displayed protocol file is the protocol of the last calculation. see also: chapter 6.5.1 Compact Protocol CadnaA - Reference Manual Compress Spectra 262 6 Chapter 6 - Calculation 6.5 Calculation Protocol Examples: 6 EXAMPLE 1: point source with the same emission time in periods D and E, but different emission in period N. In case option „(all)“ is selected, the protocol will show separate rows for each time period. For railway, separate rows for time periods are always displayed. NOTE: Option „minimum value for Lr: 0.0 dB“ ON EXAMPLE 2: point source with the same emission in all time periods D/E/ N. In case option „(all)“ is selected, the protocol will list lines marked by „DEN“ which apply to each of the time periods D/E/N. NOTE: Option "minimum value for Lr: 0.0 dB" A By selecting the period „Day“ instead of „(all)“ the protocol in example 1 would just list the rows marked by „D“ for both types of sources, in example 2, however, would still show „DEN“ for the point source, but rows marked „D“ for the railway source. CadnaA - Reference Manual 6 263 Chapter 6 - Calculation 6.5 Calculation Protocol For industrial sources, the protocol shows the column K0. The displayed value depends on the configuration setting for option „Ground Absorption“ on the „Industry“ tab (see chapter 6.2.9): • Column K0 for industrial sources (directivity index) For ground absorption models considering the increase in sound power level of the source due to ground reflections near the source within the ground absorption Aground, the column K0 just shows the value „K0 without ground“ as entered on the respective source dialog. An example is the spectral ground absorption model of ISO 9613-2 /8/ (in this example K0 = K0 without ground = 3 dB): 6 This also applies to propagation models which do not consider ground reflections near the source at all or in a different way. • For ground absorption models considering the increase in sound power level of the source due to ground reflections near the source separately (so, besides the pure ground absorption Aground), the column K0 shows the sum of the value „K0 without ground“ as entered on the respective source dialog and the calculated directivity index (e.g. K0 in VDI 2714, Domega in ISO 9613-2). An example is the non-spectral ground absorption model of ISO 9613-2 /8/ (K0 = K0 without ground + Domega, in this example 3 dB + 2.9 dB = 5.9 dB): CadnaA - Reference Manual 264 6 Option „Tables“ Chapter 6 - Calculation 6.5 Calculation Protocol Clicking this button opens a dialog enabling to edit the columns displayed on the protocol tables. 6 The protocol has a predefined column structure for each calculation standard or guideline. The calculation standards displayed depend on the current hardlock configuration. The dialog range „Standard“ is divided into four columns for standards depending on source types industry, road, railway and aircraft noise. Click on a designation in order to display the corresponding predefined table format in the dialog range „Preview“. The column headings in the preview are adjusted accordingly (see Chapter 6 - Protocol Abbreviations in the manual „Attributes, Variables, and Keywords“). CadnaA - Reference Manual 6 265 Chapter 6 - Calculation 6.5 Calculation Protocol On this dialog, the content and the format of the respective protocol table for a specific standard can be edited. By default CadnaA applies a predefined format. User-defined protocol table formats can be saved and opened. Editing the Protocol Table The basis of the format definition are the protocol table attributes (see below). 6 For further features of this dialog, see chapter 11.1.2 "Editing Object Tables". Select „User-defined Table“ and double-click into a table row to edit the column or select the command Edit from the context menu. This opens the dialog Table Column enabling to enter headlines and to define the column content. For further features of this dialog see chapter 11.1.2 "Editing Object Tables", section "Dialog Table Column". CadnaA - Reference Manual Dialog Table Column 266 6 Attributes for Protocol Tables 6 Chapter 6 - Calculation 6.5 Calculation Protocol The following protocol table attributes are available: Attribute Description NUM number of the ray HSRC Handle Source (internal object No.) HRCV Handle Receiver (internal object No.) NORM number of the standard (internal) PART_SRC number of the partial source (internal) X x-coordinate Y y-coordinate Z z-coordinate GROUND ground height REFLORD order of reflection DEN designation of time period DEN, D, E, N FTYP frequency type (S = spectrum, C = compressed spectrum (single value), A = A-weighted level) FREQ frequency (third-octave or octave) LW sound power level (linear) LW_A A-weighted sound power level LR partial level, receiver (linear) LR_A A-weighted partial level, receiver C_LENAREA correction length/area C_OPTIME correction for operating time C_K0 directivity index (sum of value entered for „K0 w/o ground“ and of K0/D resulting from propagation calculation - if any) C_DIR correction directivity C_DIV correction divergence CadnaA - Reference Manual Chapter 6 - Calculation 6.5 Calculation Protocol C_AIR correction air absorption C_GROUND correction ground attenuation C_BAR correction barrier attenuation C_BEB correction attenuation due to built-up areas C_BEW correction attenuation due to foliage C_PHI correction aspect angle C_MET correction meteorology C_DREFL correction for multiple reflections C_STEIG correction gradient correction C_RL correction reflection loss C_CONST constant (internal) C_C1 correction C1 (link depends on standard, see table below) C_C2 correction C2 (link depends on standard, see table below) C_C3 correction C3 (link depends on standard, see table below) C_C4 correction C4 (link depends on standard, see table below) C_C5 correction C5 (link depends on standard, see table below) C_C6 correction C6 (link depends on standard, see table below) below attributes for geometry: G_DIST 3D distance (m) G_HM average height (m) G_SCR_Z path difference z (m) G_SCR_DSS 3D distance source - first diffracting edge (m) G_SCR_DSR 3D distance last diffracting edge - receiver (m) G_SCR_E distance first - last diffracting edge (m) CadnaA - Reference Manual 6 267 6 268 6 Chapter 6 - Calculation 6.5 Calculation Protocol G_SCR_DPAR distance source - rcvr, measured parallel to diffr. edge (Schall03-2013, m) G_LENBEB propagation path length through built-up area (m) G_LENBEW propagation path length through foliage (m) below attributes for aircraft noise: 6 F_ACFT aircraft group F_CORR_NR number of corridor F_SIGMA arc length (m) F_SEG_S segment length, start (m) F_SEG_E segment length, end (m) F_D arc length (m) F_Z additional level (dB) / power setting F_V speed (m/s) F_H height at fly-over point (m) F_TIME_A time aircraft (s) F_TIME_R time receiver (includes propagation time, s) F_RHO perpendicular distance (m) F_CORRW corridor width (m) CadnaA - Reference Manual 6 269 Chapter 6 - Calculation 6.5 Calculation Protocol corrections C1..C6 depending on standard: Standard C_C1 C_C2 C_C3 C_C4 C_C5 C_C6 Concawe K5 - - - - - AsolF AdifF - - - - K - - - - - DLka DLts - - - - Agr/bar/ reflN Agr/bar/ reflF - - - - Cball - - - - - A - - - - - AzB 08 SEL Lmax - - - - ECAC Doc.29 3rd Ed. INM CNOSSOS-EU SEL Adur Arev Aimp - - NMPB-Ind-08 NMPB-Routes-96 NMPB-Routes-08 NMPB-Fer NMPB-Fer-08 CNOSSOS-EU RLS-90 STL 86 CRTN Nordic Pred. Method SonRoad CRN AzB 75 ECAC Doc.29 DIN 45684 ÖAL 24 CadnaA - Reference Manual 6 270 6 Open protocol file using a SQL editor Chapter 6 - Calculation 6.5 Calculation Protocol The CadnaA protocol file (file extension cnaprot) is saved using the SQLite database format which can be opened using a SQLite editor (e.g. DB Browser for SQLite), see: https://github.com/sqlitebrowser/sqlitebrowser/releases Requirements & Support 6 Basic SQL knowledge is required in order to use the database browser properly. Please consider that the CadnaA maintenance contract does not cover the development or the debugging of SQL database queries. If you need further assistance, please contact DataKustik to obtain a quote for this service. CadnaA - Reference Manual Chapter 6 - Calculation 6.5.1 Compact Protocol 6.5.1 6 271 Compact Protocol The compact protocol is available just for industry sources calculated according to ISO 9613. Use the Compact Protocol to produce a single value for the effective screening coefficient and the proportion of reflected sound, referred to the overall source, line by line for each source, even extended sources such as area or line sources. When calculating, e.g., an area source with screening, the values with and without a screen are calculated automatically, and the effective screening coefficient is indicated as the difference Abar,eff. Procedure: • For the compact protocol, generate a protocol via the menu command Calculation|Protocol (see chapter 6.5). • Restart the calculation for receivers. The protocol file is written. • Then compress it using File|Export, Export format „Compact protocol“ and specify a filename. • Enter file name, CadnaA automatically adds the extension TXT. • Click OK to confirm. Now, CadnaA creates an ASCII file containing TAB-separated data with the following column headings: Name ID Freq LxT CadnaA - Reference Manual LxN LrT LrN Refl Abar,eff 6 272 6 Chapter 6 - Calculation 6.5.1 Compact Protocol 6 CadnaA - Reference Manual 6 273 Chapter 6 - Calculation 6.6 Multithreading 6.6 Multithreading CadnaA makes offers multi-threading and, thus, makes full use of the multi- processor CPUs. Since all new desktop- and laptop-PCs use multi-core CPUs, this will cut down calculation times significantly. CadnaA is prepared to use up to 64 parallel processors (requires Option 64). In CadnaA 32-Bit just up to 32 processors are available! By default, the option „All available“ is selected on dialog Calculation|Multithreading. Alternatively, CPU usage can be extended to all processors or to a selection of processors. Make your selections and close the dialog with OK. CadnaA will save the settings and reload them after a restart. CadnaA - Reference Manual Used Processors 6 274 6 Multi-Threaded Processes in CadnaA Chapter 6 - Calculation 6.6 Multithreading CadnaA makes use of multi-threading for the following calculation tasks: • receiver points, as long as the calculation protocol is not activated (menu Calculation|Protocol), • building evaluations or facade points, respectively, and • horizontal and vertical grids. 6 CadnaA - Reference Manual Chapter 6 - Calculation 6.7 Multiple Source Effect 6.7 6 275 Multiple Source Effect The dialog Multiple Source Effect (Calculation menu) enables to evaluate different scenarios with respect to traffic noise impact by calculating the „effect related substitute level“ according to the VDI guideline 3722-2 /44/. Applying the assessment requires facade levels calculated using building evaluations (see chapter 5.4) for road, railway and aircraft noise in separate variants (see chapter 14.2) for the evaluation parameters Lden and Lnight and the number of inhabitants per building (see chapter 3.1.1). The following results are generated: • the „effect related substitute level“ at facade points and in the building evaluation symbols, • the parameters Annoyed Persons (AP), Highly annoyed Persons (HAP), Sleep disturbed (SD) and Highly sleep disturbed persons (HSD) are written into string variables stored on the Memo-Window of each building. Industrial noise is neither included, nor assessed by the VDI guideline 3722-2 /44/. CadnaA - Reference Manual Application to Facade Points and Building Evaluations 6 276 6 Application to the Grid and to Receivers Chapter 6 - Calculation 6.7 Multiple Source Effect Basically, the evaluation according to VDI guideline 3722-2 in CadnaA does not refer to the grid or receiver points, since the number of persons AP/ HAP/SD/HSD is to be determined primarily. In CadnaA, however, the „effect related substitute level“ can be calculated on the grid and at receivers as well. To this end, select the formula expression „f(x)“ from the „Evaluation Parameters“ tab (see chapter 6.2.5) and via the double arrow (>>) from the parameter group „VDI 3722“ the evaluation parameters Lden (DEN) and Ln (Night). 6 Now, the „Evaluation Parameters“ tab may look like this: CadnaA - Reference Manual 6 277 Chapter 6 - Calculation 6.7 Multiple Source Effect Dialog Options The following options are available: • VDI 3722: Calculation of the parameters Annoyed Persons (AP), Highly annoyed Persons (HAP), Sleep disturbed (SD) and Highly sleep disturbed persons (HSD) considering the noise impact of several sources types road, rail and/or aircraft noise, based on the VDI guideline 3722-2:2013. • VDI 3722 (A7, A8, A15, A16): With this option, the method according to the afore-mentioned edition of VDI 3722-2 is strictly applied using the inverse functions (A7), (A8), (A15) and (A16) mentioned there. As a mathematical error in these functions in VDI 3722-2 occurred an alternative method (i.e. the option „VDI 3722“) was implemented applying a numerically correct inversion of the original functions (A1), (A4) and (A9) and (A12). With regard to a possible revision of the guideline it is recommended, therefore, to use the option „VDI 3722“ instead. • Calculation Method 6 HAP: The noise evaluation method according to Miedema /88/ generates three indicators: Highly Annoyed Persons (HAP), highly sleep disturbed persons (HSD) and the statistical value of expectation of noise-induced myocardial infarction (NMI). Select for the noise types „Road“, „Railway“ and „Aircraft“ one of the available variants to be used for the assessment. This requires that for up to three noise types separate variants have to be enabled and calculated. By selecting „(none)“ the respective noise type is not included into the HAP calculation. Select in line „Save total in“ the target variant (that is, another „empty“ variant) to be used to display the „effect related substitution level“ at the facade points and on the building evaluation symbols. The calculation of the substitution levels for Lden is based on the fraction HA and for Ln the fraction HSD. Note that no levels <42 dB(A) can be mapped for the substitution level Lden. CadnaA - Reference Manual Assignment of Variants 278 6 Chapter 6 - Calculation 6.7 Multiple Source Effect By selecting this variant and the evaluation parameters according to VDI 3722 (see section "Application to the Grid and to Receivers"), the „effect related substitution levels“ are displayed both on the grid, at receivers and at facade points/building evaluation symbols. Assignment of Evaluation Parameters The noise evaluation method according to Miedema and the procedure in VDI 3722-2 refers to the levels Lden and Lnight. Assign using these list boxes which of the currently available evaluation parameters is linked to the two levels Lden and Lnight. In case Lden and Ln have been chosen as the first and the second evaluation parameter, no change is required. Option "Detailed Results" If this option is activated, the evaluation occurs for the different noise types individually as assigned by the variant and for total noise (e.g. HAProad, HAPrail, HAPair, HAPtot etc.). Option "Protocol File" With this option activated, the results of the HAP calculation are written into the specified text file. If necessary enter a file name and select the directory via the file selector symbol. Button OK Clicking this button starts the evaluation and writes the results into the Memo-Window of the buildings (and exported, with the option above selected). Button „Export“ Via this button, the calculation results at the facade points are exported to a Shape file (ArcView *.shp). The geometry corresponds with the 3D-Shapeexport of facade points (see chapter 13.3.2), but here the results for the various noise types are written to the following string variables (see dialog Memo-Window of the auxiliary polygons): 6 • • • NAME, BLDG_ID: name and ID of the facade point (or BuildEval) RES_RECV_N: number of residents at the facade point (assuming RES_RECV_N = EINW/(number of facade points) evaluation parameters LP1 and LP2 for noise types R=road, RW=railway, A=aircraft (in dB) CadnaA - Reference Manual 6 279 Chapter 6 - Calculation 6.7 Multiple Source Effect In the first step, the source type specific building noise maps are calculated. Procedure In order to evaluate the grid and receivers as well, select the two VDI specific evaluation parameters on the „Evaluation Parameters“ tab (see above). • Select the Lden as evaluation parameter 1 and Ln as evaluation parameter 2 via menu Calculation|Configuration. • Assign roads, railways and air routes each to a single variant (e.g. using the short variant names ROAD, RAIL and AIR). • Define at least one further variant where the results of the multiple source effect calculation according to VDI 3722-2 are written to. • Enter a building evaluation symbol at some location and enter on the dialog part „Options“ the following values: Height of Storey (m): 1000 (accord. to VDI 3722 just facade points at a single height are used) Height Rcvr EG above Ground (m): 4 • Close the dialog by OK. • Generate the building evaluation symbol for all buildings to be considered (via dialog Modify Objects, action „Generate Building Evaluation“). CadnaA - Reference Manual 6 280 6 Chapter 6 - Calculation 6.7 Multiple Source Effect • Now, delete the initial building evaluation symbol used to specify the height settings. • Calculate the facade levels for all or the variants to be considered (via menu Calculation|Calc). • If necessary, start the grid calculation for all or selectable variants via the menu Grid|Calculate grid. In the second step is the parameters describing the multiple source effect are calculated. 6 Examples\06_Configuration\VDI 3722-2 • Open the dialog Multiple Source Effect on the Calculation menu. • Select the calculation method and address the variants to the source types. • Specify the variant the „effect related substitute level“ shall be written to. • Address the evaluation parameters and start the calculation with OK. On the Memo-Window of the buildings the calculated values are displayed. These can be evaluated statistically using CadnaA specific procedures or in tables or can be presented as a map by spatial averaging using ObjectScan (see chapter 15.1). Dialog Memo-Window of a building with text variables showing resulting values according to VDI 3722-2 CadnaA - Reference Manual Chapter 6 - Calculation 6.7.1 Monetary Evaluation of Noise according to BUWAL 6.7.1 6 281 Monetary Evaluation of Noise according to BUWAL see chapter 15.5 6 CadnaA - Reference Manual 282 6 Chapter 6 - Calculation 6.7.2 QSI - Statistical Analysis 6.7.2 QSI - Statistical Analysis The "Requirements and Testing Conditions for statistical qualification of level differences" stated in DIN 45687 /33/, annex F (available in German only) are implemented in CadnaA. To statistically evaluate the level differences from two calculation runs with different configuration settings the 0.1-quantile and the 0.9-quantile are calculated and displayed (10%- resp. 90 %-value of the distribution of the level differences). 6 The command QSI-Statistical Analysis is available via the menu Tables |Miscellaneous. The evaluation may be applied to grid points, to facade points or to points on lines of equal sound level (Iso-Lines). Dialog QSI - Statistical Analysis CadnaA - Reference Manual 6 283 Chapter 6 - Calculation 6.7.2 QSI - Statistical Analysis The statistical evaluation in CadnaA considers all active receiver points (minimum number of receivers = 20). The additional requirement according to annex F of DIN 45687 regarding a minimum horizontal distance of userdefined receivers of 2 m from sources and obstacles has to be ensured by the user himself. When receivers are generated by CadnaA the minimum horizontal distance will be respected automatically. Specify which of the variants in the project file should be considered as reference configuration and as project configuration. Normally, the setting „(default“)“ applies for the reference configuration which is defined globally (see below, Reference Configuration). With the default reference configuration selected, the additional variant „REF“ (corresponding with variant V16) will be listed on the list boxes „Reference Configuration“ and „Project Configuration“ after calculation. Assignment of Variants As far as the reference configuration is concerned the default values (setting „Default“) can be applied or be altered by the user (setting „User defined“). In the latter case the default reference configuration values will be listed in the box upon click onto the button „Copy Default“. The parameters listed in the table below are available for the time being.. Reference Configuration parameter (unit / value range) variable/default value maximum error (dB): search radius (m): grid interpolation on/off (1/0): raster factor (-): projection of line sources on/off (1/0): projection of area sources /off (1/0): order of reflection (1-20): max. distance source-receiver (m): ibid, interpolate from (m): reflector-search radius source (m): reflector-search radius receiver (m): MAXERROR=0.0 SEARCHRAD=3000 RASTER_INT=0 RASTERFACT=0.5 PROJ_LQ=1 PROJ_FQ=1 REFLORDER=1 REFL_DMAX=3000 REFL_DMAXI=3000 REFL_RAD_S=3000 REFL_RAD_R=3000 The reference configuration settings can be changed by entering different values for the parameters as required. CadnaA - Reference Manual 6 284 6 Chapter 6 - Calculation 6.7.2 QSI - Statistical Analysis Evaluation Parameter Select the evaluation parameter used for the statistical evaluation. With setting „(current)“ the active performance parameter is used. Test Points DIN 45687, annex F, requires a minimum number of 20 receivers for the evaluation. use existing Receivers In order to use the existing receivers shall, their ID must be changed to the text string „QSI“ in order to be considered upon calculation. generate new Receivers By activating the option „generate new Receivers“ three options are available: 6 Calculation of Test Points • Grid Points: By clicking the „Calculate“ button the specified number of receivers will be generated at arbitrary locations. With a calculation area defined the receiver points will be distributed inside that area, otherwise within the entire limits. • Facade Points: By clicking „Calculate“ the specified number of facade points (as QSI-receivers) will be generated at arbitrary locations (at a distance off the facades specified on dialog Building Noise Map). The generation of facade receivers requires to generate building evaluation symbols for a reasonable number of buildings in the project (or for all buildings). Facade receivers will just be generated for buildings having a building evaluation symbol addressed. • Points on Iso-Lines: With this option the approach is different. First, select on dialog Configuration of Calculation the project configuration as required and recalculate the grid (via Grid menu). Now, select on dialog QSI-Statistical Analysis the option „Points on Iso-Lines“ and change - if required - the reference configuration. By clicking „Calculate“ the specified number of receiver will be generated at arbitrary locations on the iso-line with the specified level. This option requires that a valid grid exists. The appearance of the grid is not relevant. This option enables to control whether the reference and/or the project configuration should be considered upon recalculation. In case of evaluation options „Grid Points“ and „Facade Points“ the settings of the project configuration can be altered directly via the file-selector symbol. CadnaA - Reference Manual 6 285 Chapter 6 - Calculation 6.7.2 QSI - Statistical Analysis This box displays the results of the statistical evaluation, as there are: resulting parameters abbreviation 0,1-quantile 0,9-quantile standard deviation of level differences mean value of level differences minimum level difference maximum level difference q0.1 q0.9 sigma mean min max Results The lower table displays the coordinates of the receiver points, the levels for the reference and then project configuration, and the level differences. Individual Results Upon click on the button „--> Word“ both configuration settings, the results for the statistical parameters, and the individual results will be exported to MS-Word. The template file QSI_TMPL.RTF supplied with CadnaA (see installation directory) can be edited by the user. Word-Export In section „Configuration“ only those parameters are displayed where the reference and the project configuration differ from each other. At the end of a QSI-analysis, this enables to check whether the intended settings for both configurations have been set correctly. CadnaA - Reference Manual 6 286 6 Example 6 Chapter 6 - Calculation 6.7.2 QSI - Statistical Analysis The influence of the projection of line sources on the receiver level shall be statistically be evaluated for a project with roads and buildings. The receiver points for QSI-analysis will be generated by CadnaA. In the reference configuration, the projection of line and area sources shall be turned off and the maximum error shall be set to 1 dB. Open the QSI-dialog an assign the variant „(default)“ for the reference and V01 for the project configuration. To check for the default-reference settings switch to „User defined“ and click the button „Copy default“ to display all relevant parameters. The project configuration shall comply with this reference configuration, besides the projection for line sources deactivated. To check and alter the project configuration, click on the file-selector symbol in the dialog section „Calculation of Test Points“. Ensure that the projection of line and area sources on tab „Partition“ is deactivated and enter on tab „General“ a maximum error of 1 dB. Run the calculation with options „Test Points, generate new Receivers, 20 Grid Points“. The result is displayed below. CadnaA - Reference Manual Chapter 6 - Calculation 6.7.2 QSI - Statistical Analysis 6 287 6 QSI-result after calculation The exported MS-Word-file indicates that the project configuration differs from the reference configuration just by the setting of projection of line sources (template file QSI_TMPL.RTF edited). CadnaA - Reference Manual 288 6 Chapter 6 - Calculation 6.7.2 QSI - Statistical Analysis 6 CadnaA - Reference Manual Chapter 6 - Calculation 6.8 QSI - Statistical Analysis 6.8 6 289 QSI - Statistical Analysis The "Requirements and Testing Conditions for statistical qualification of level differences" stated in DIN 45687 /33/, annex F (available in German only) are implemented in CadnaA. To statistically evaluate the level differences from two calculation runs with different configuration settings the 0.1-quantile and the 0.9-quantile are calculated and displayed (10%- resp. 90%-value of the distribution of the level differences). The command QSI-Statistical Analysis is available via the menu Tables |Miscellaneous. The evaluation may be applied to grid points, to facade points or to points on lines of equal sound level (Iso-Lines). Dialog QSI - Statistical Analysis CadnaA - Reference Manual 6 290 6 Chapter 6 - Calculation 6.8 QSI - Statistical Analysis The statistical evaluation in CadnaA considers all active receiver points (minimum number of receivers = 20). The additional requirement according to annex F of DIN 45687 regarding a minimum horizontal distance of userdefined receivers of 2 m from sources and obstacles has to be ensured by the user himself. When receivers are generated by CadnaA the minimum horizontal distance will be respected automatically. Assignment of Variants Specify which of the variants in the project file should be considered as reference configuration and as project configuration. Normally, the setting „(default“)“ applies for the reference configuration which is defined globally (see below, Reference Configuration). With the default reference configuration selected, the additional variant „REF“ (corresponding with variant V16) will be listed on the list boxes „Reference Configuration“ and „Project Configuration“ after calculation. Reference Configuration As far as the reference configuration is concerned the default values (setting „Default“) can be applied or be altered by the user (setting „User defined“). In the latter case the default reference configuration values will be listed in the box upon click onto the button „Copy Default“. The parameters listed in the table below are available for the time being.. 6 parameter (unit / value range) variable/default value maximum error (dB): search radius (m): grid interpolation on/off (1/0): raster factor (-): projection of line sources on/off (1/0): projection of area sources /off (1/0): order of reflection (1-20): max. distance source-receiver (m): ibid, interpolate from (m): reflector-search radius source (m): reflector-search radius receiver (m): MAXERROR=0.0 SEARCHRAD=3000 RASTER_INT=0 RASTERFACT=0.5 PROJ_LQ=1 PROJ_FQ=1 REFLORDER=1 REFL_DMAX=3000 REFL_DMAXI=3000 REFL_RAD_S=3000 REFL_RAD_R=3000 The reference configuration settings can be changed by entering different values for the parameters as required. CadnaA - Reference Manual 6 291 Chapter 6 - Calculation 6.8 QSI - Statistical Analysis Select the evaluation parameter used for the statistical evaluation. With setting „(current)“ the active performance parameter is used. Evaluation Parameter DIN 45687, annex F, requires a minimum number of 20 receivers for the evaluation. Test Points In order to use the existing receivers shall, their ID must be changed to the text string „QSI“ in order to be considered upon calculation. use existing Receivers By activating the option „generate new Receivers“ three options are available: generate new Receivers • Grid Points: By clicking the „Calculate“ button the specified number of receivers will be generated at arbitrary locations. With a calculation area defined the receiver points will be distributed inside that area, otherwise within the entire limits. • Facade Points: By clicking „Calculate“ the specified number of facade points (as QSI-receivers) will be generated at arbitrary locations (at a distance off the facades specified on dialog Building Noise Map). The generation of facade receivers requires to generate building evaluation symbols for a reasonable number of buildings in the project (or for all buildings). Facade receivers will just be generated for buildings having a building evaluation symbol addressed. • Points on Iso-Lines: With this option the approach is different. First, select on dialog Configuration of Calculation the project configuration as required and recalculate the grid (via Grid menu). Now, select on dialog QSI-Statistical Analysis the option „Points on Iso-Lines“ and change - if required - the reference configuration. By clicking „Calculate“ the specified number of receiver will be generated at arbitrary locations on the iso-line with the specified level. This option requires that a valid grid exists. The appearance of the grid is not relevant. This option enables to control whether the reference and/or the project configuration should be considered upon recalculation. In case of evaluation options „Grid Points“ and „Facade Points“ the settings of the project configuration can be altered directly via the file-selector symbol. CadnaA - Reference Manual 6 Calculation of Test Points 292 6 Results 6 Chapter 6 - Calculation 6.8 QSI - Statistical Analysis This box displays the results of the statistical evaluation, as there are: resulting parameters abbreviation 0,1-quantile 0,9-quantile standard deviation of level differences mean value of level differences minimum level difference maximum level difference q0.1 q0.9 sigma mean min max Individual Results The lower table displays the coordinates of the receiver points, the levels for the reference and then project configuration, and the level differences. Word-Export Upon click on the button „--> Word“ both configuration settings, the results for the statistical parameters, and the individual results will be exported to MS-Word. The template file QSI_TMPL.RTF supplied with CadnaA (see installation directory) can be edited by the user. In section „Configuration“ only those parameters are displayed where the reference and the project configuration differ from each other. At the end of a QSI-analysis, this enables to check whether the intended settings for both configurations have been set correctly. CadnaA - Reference Manual 6 293 Chapter 6 - Calculation 6.8 QSI - Statistical Analysis The influence of the projection of line sources on the receiver level shall be statistically be evaluated for a project with roads and buildings. The receiver points for QSI-analysis will be generated by CadnaA. In the reference configuration, the projection of line and area sources shall be turned off and the maximum error shall be set to 1 dB. Open the QSI-dialog an assign the variant „(default)“ for the reference and V01 for the project configuration. To check for the default-reference settings switch to „User defined“ and click the button „Copy default“ to display all relevant parameters. The project configuration shall comply with this reference configuration, besides the projection for line sources deactivated. To check and alter the project configuration, click on the file-selector symbol in the dialog section „Calculation of Test Points“. Ensure that the projection of line and area sources on tab „Partition“ is deactivated and enter on tab „General“ a maximum error of 1 dB. Run the calculation with options „Test Points, generate new Receivers, 20 Grid Points“. The result is displayed below. CadnaA - Reference Manual Example 6 294 6 Chapter 6 - Calculation 6.8 QSI - Statistical Analysis 6 QSI-result after calculation The exported MS-Word-file indicates that the project configuration differs from the reference configuration just by the setting of projection of line sources (template file QSI_TMPL.RTF edited). CadnaA - Reference Manual Chapter 6 - Calculation 6.8 QSI - Statistical Analysis 6 295 6 CadnaA - Reference Manual 296 6 Chapter 6 - Calculation 6.8 QSI - Statistical Analysis 6 CadnaA - Reference Manual 6 297 Chapter 6 - Calculation 6.9 Batch Operation 6.9 Batch Operation It is possible with CadnaA to automatically calculate in succession a grid or individual receiver points. This is especially interesting for long-term calculations if you, e.g., want to calculate different variants during the weekend or over-night. The required steps to set-up the batch processing are explained in the following. Change Command starting CadnaA • Activate the CadnaA link on the WINDOWS desktop by clicking it with the right mouse button. • Select the context menu command Properties. • Insert into the box „Target“, after the string „cna32.exe“ a single blank and the following string: /batch=1 Subsequently, the dialog looks like shown on the following page. CadnaA - Reference Manual 6 298 6 Chapter 6 - Calculation 6.9 Batch Operation 6 Input box „Target“ extended by „ /batch=1“ CNABATCH IN and OUT • Create a directory CNABATCH on your C-drive. In CNABATCH, create two sub-directories called IN and OUT. Naming the sub-directories IN and OUT is mandatory! CNABATCH is the default directory for the batch feature. If you use this name, no modification of the Cadnaa.ini file is required. (If you wish to use a different name, see below.) The paths then are: C:\CNABATCH\IN C:\CNABATCH\OUT CadnaA - Reference Manual Chapter 6 - Calculation 6.9 Batch Operation • Copy all those *.CNA files to be processed into the IN directory. It goes without saying that in each project file the calculation configuration and the immission point grid must be defined accordingly. If you do not stick to the default directory name CNABATCH on drive C, an entry must be made in the file CADNAA.INI residing in the Windows directory (e.g., ...\WINDOWS (for Windows 3.11/95) or ...\WINNT (for Windows NT) etc.). • 6 299 Entry in CADNAA.INI if necessary Open this file using an editor and insert the path where your two directories IN and OUT are, in the series of commands following the header [Main]. If, for example, the directory is WEEKEND instead of CNABATCH, and WEEKEND itself contains in a directory CADNAA_W, you will have to insert the following line: 6 BatchDir=C:\CADNAA_W\WEEKEND • Then save the file and close it. When CadnaA is launched with the parameter /batch=1 on the expanded command line, it will check the IN directory for files every 30 seconds. If any files are found, these will be opened and calculated one by one. The results will be saved under the same name in the OUT directory, and the files already calculated are deleted from the IN directory. Once CadnaA has processed all files, close the program as usual. CadnaA - Reference Manual Launching the automatic calculation 300 6 Chapter 6 - Calculation 6.9 Batch Operation CadnaA should not be run using the batch mode for normal project work, but just for batch calculations because in the batch mode the software attempts to open any files in the IN-directory. In order to save the trouble of having to delete and re-enter the batch parameters on the command line over and over again, you may wish to create an additional CadnaA shortcut on the WINDOWS desktop (e.g. by copying) where the batch parameter is set permanently. For clarity, the new shortcut might be named, e.g. CadnaA-Batch. Use this shortcut to launch the program for a batch calculation. 6 This enables a highly time-efficient and professional work with CadnaA, particularly if several PCs are available in a network. In this context also pay attention to the comprehensive facility of PCSP (Program Controlled Segmented Processing) - (see chapter 6.10). Processing Order There need to be distinguished: • Order of processing with several CadnaA files in the batch directory IN: The processing occurs according to the date of the CadnaA file, with the oldest calculated first, etc. • Order of processing of the tiles within a CadnaA file: The individual tiles are processed according to their order in the table „Section“ (from top down). The order when last saving the CadnaA file is relevant. The assigned PART number in the ID of the tiles (PART: xxx) is not relevant for the processing order. CadnaA - Reference Manual 6 301 Chapter 6 - Calculation 6.9 Batch Operation By the BATCH command it is possible to execute calculations automatically for grids (noise map) or individual receiver points for several files or to continue a stopped calculation at the point where it has been stopped. The selection of the desired mode is controlled by parameters in text blocks (see chapter 12.5). If you do not create a text block a grid is calculated automatically. To define parameters for calculations in the Batch mode create a local text block named CNABATCH (pay attention to the capital letters). Enter one or more of the following commands to execute the corresponding calculation: Parameter equals calculation of CALC_IMM 0 no receiver points (default) CALC_IMM 1 receiver points (active variant only) CALC_IMM 2 receiver points (all variants) CALC_ RASTER 0 no grid CALC_ RASTER 1 grid (active variant only, default) CALC_ RASTER 2 grid (all variants) UPDATE_RASTER 1 continues an interrupted calculation from break position (equals selecting the command Grid|Calc Grid while holding down the SHIFT key) CALC_MESSAGE CALC_POLL Computer1 1 calculation of air pollution with option APL CALC_IMM corresponds as well to the individual inserted receivers as to the building evaluation. CadnaA - Reference Manual Options BATCH Command 6 302 6 Chapter 6 - Calculation 6.9 Batch Operation 6 Local text block CNABATCH Several Computers and the Batch Command Access to the same folder/directory through several computers is unambiguously regulated in the Batch mode. If a file is opened, the extension of this file is renamed from CNA in CNC - another opening of this file is therefore impossible. After finishing the calculation the extension is again renamed in CNA and saved in the corresponding OUT directory. Message after finishing the calculation A message can be displayed by CadnaA when a calculation has terminated. This requires that a message software (e.g. WinPopUp) is installed to your computer and that a local text block CALC_MESSAGE has been defined in the CadnaA file. In this text block, the PC‘s path or the PC‘s name which should receive the message must be defined. Partial Levels at Receivers using Batch-mode Partial levels at receivers are generated when using normal batch mode (i.e. without tiled the project area). Set CALC_IMM=1 (for the active variant) in the local text block CNABATCH. Calculating this file with batch calculation will return partial levels at receivers. CadnaA - Reference Manual 6 303 Chapter 6 - Calculation 6.10 PCSP - Program Controlled Segmented Processing 6.10 PCSP - Program Controlled Segmented Processing CadnaA is able to process more than 16 million objects per object type without any problems, even models of cities. Therefore, the limiting file size is normally given by the PCs RAM. Using PCSP even this limit is irrelevant. Program controlled segmentation with user-defined partitioning allows you to load automatically the segments one after another for calculation. Thus the RAM is able to work without hard disk access. 6 If several CadnaA computers are at your disposal for calculation, e.g. within a network, they can simultaneously process the same project file. PCSP with its PCSP-Part-Viewer by CadnaA automatically organizes and manages the required processes. In order to specify a directory for the batch-calculation select form the menu Calculation|PCSP the command Choose Batch-Directory. On the subsequent dialog you may either select an existing directory or generate a new one. Upon confirmation by OK CadnaA creates the sub-directories IN and OUT within the selected directory. Choose BatchDirectory 1. Generate in your file to be calculated sections used the subdivide the area into equal sized tiles. This procedure is called "tiling" (see chapter 9.10). Activating PCSP 2. Give the