Michael White (USA) ERDC-CERL/US Army, Illinois
Karl-Wilhelm Hirsch (Germany) - IFL, Dusseldorf
B Vogelsang (Germany) - IFL, Dusseldorf
Frank van den Berg (Netherlands) - TNO, Delft
Pieter van der Weele (Netherlands) - DGW&T, The Hague
Erik van Arkel (Netherlands) - DGW&T, The Hague
George Wong (Canada) - CSA, Toronto
Peter Teague (Australia) - SAI/AAS/Vipac, Adelaide
Meeting Agenda, Discussion and Outcomes:
Michael White (Convenor of WG40) opened and chaired the meeting (8 June).
The following points provide an overview of the meeting agenda and discussion/outcomes:
Last meeting minutes (Champaign-Illinois, USA, Sept 2004) were discussed and approved.
The submission of first Committee Draft (CD) to the ISO Secretariat needed by August 2005. This will be based on revising draft Technical Specification ISO/TS 13474 (Acoustics — Impulse Sound Propagation for Environmental Noise Assessment, First edition dated 2003-01-15).
Considerable attention was devoted to the content and wording of the Introduction and Scope of the CD, including addressing comments from voting on the initial draft TS (document 1N1316).
Reference to ISO 10843 and ISO 17201 (WG51) as well as ISO 1996 needed in the Introduction. Also clarify the inapplicability of ISO 9613-2. Make clear the need for more details relating to meteorological conditions, ground absorption, turbulence/scattering and topography. Also, need to make clear that this standard has the starting point of source strength (determined in ISO 17201).
A description of the range of available algorithms and worked examples needs to be formulated in an Informative Appendix. Another Informative Appendix will cover the conversion to time-weighted descriptors and levels (using reference to work done in working group WG51).
The range of propagation methods available and their relative merits was discussed, including ray-tracing methods, wave field methods, caustics, runtimes, database simplifications and sound velocity profiles.
Most of the meeting was devoted to discussing two major scope changes for ISO 13474 standard.
Proposal to change scope of draft standard to incorporate appropriate sections (parts 1, 2 & 4) of ISO 17201 (for shooting ranges; WG51), which will make the ISO 13474 standard more consistent and robust. In ISO 17201 part 1, 2, 4, procedures (for small weapons/shooting ranges) are defined to describe the blast source strength, non-acoustical source features and projectile noise, which also apply to blasts from heavy weapons and high explosives. The rest of ISO 17201 is not appropriate for application to larger, higher energy blasts where larger distances are involved and meteorological conditions have a greater impact.
Proposal (by P. Teague and supported by K. Hirsch and rest of committee) to expand the scope of the draft ISO 13474 standard to treat short-term prediction, which can be used as a forecasting tool. This will supplement the long-term average level prediction and will involve the formulation of additional calculation methods. This will make the standard more widely applicable and usable.
A formal Resolution, covering the proposed scope changes (see 8 & 9 above), was formulated and agreed by the committee for submission to the ISO Secretariat (Document N063).
I was able to provide input to the working group on a range of technical issues and on the terminology, definitions, wording and grammar to be used throughout the draft standard.
After the meeting, final edits and changes were made to the proposed Committee Draft by the committee and finalised by Michael White. The first Committee Draft (1CD 13474) was submitted to the ISO Secretariat on 23rd August 2005.
Given the strong link and technical overlap between working groups WG40 and WG51 (Noise from Shooting Ranges), I was an invited observer at the WG51 meeting (6-7 June) in Toronto. I was able to provide input to the WG51 working group on some technical issues and, in particular, was able to provide substantial input on the English wording, terminology, definitions and grammar used in the ISO 17201 standard. Much discussion was directed towards voting comments relating to Part 3 of standard (Guidelines for sound propagation calculations) and to finalise as an FDIS. Part 1 has been printed, Parts 2 and 4 are being finalised as an FDIS and Part 5 to be completed in Feb 2006.
I also attended and participated in the ISO/TC43 Plenary session (9-10 June) in Toronto, as Head of Delegation for Australia being the only Australian representative present (see separate report).
The issues and inputs/outputs of the ISO WG are closely aligned with, and complementary to, those of my Standards Australia EV committees, particularly the EV-010 Community Noise Committee. My involvement in WG40 has provided an important link to the EV committees, Standards Australia and the acoustics community (AAS). I will be seeking input and feedback from others in Australia and looking to consider adoption of the working committee drafts in Australia.
I look forward to contributing greatly to the next crucial meeting of the working group and hope to receive sufficient funding support from SAI to help me attend.
