SIMULATION OF FIRST AND SECOND ORDER SCATTERING BY ROUGH SURFACES WITH A SOUND RAY FORMALISM
✍ Scribed by J.J. EMBRECHTS
- Publisher
- Elsevier Science
- Year
- 2000
- Tongue
- English
- Weight
- 249 KB
- Volume
- 229
- Category
- Article
- ISSN
- 0022-460X
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✦ Synopsis
The sound ray technique is developed to simulate rough surfaces scattering processes which are consistent with the Kirchho! approximation (KA) theory. It is "rst proved that both approaches (KA and sound rays) lead to the same theoretical expression of the "rst-order scattered intensity. An algorithm based on the random generation of surfaces' slopes is proposed, together with some results computed for Gaussian rough surfaces. This algorithm could be used in room acoustics more as a physical substitute for the cosine Lambert law of di!usion. The method is then extended to the analysis of second-order scattering e!ects, which are not taken into account by KA. This new approach does not require the generation of several pro"les of rough surface. However, some assumptions must be made in order to derive a useful mathematical expression of the second-order scattered intensity. The "rst results obtained are fairly consistent with the present knowledge of multiple scattering e!ects (e.g., enhanced backscattering for very rough surfaces), but further work is needed to test the assumptions and to improve the method.