Prediction of the scattering properties of surfaces by laser scanning of height profile

Measurement of scattering data for existing room surfaces is difficult. This results in problems in using and validating computer models of room acoustics. This paper discusses the use of an optical laser scanning technique to obtain the geometrical data for the room surfaces. It is shown how the surface geometrical data can be described by spatial spectra, and how these relate to the scattering properties. Results for the angular scattering properties obtained by the geometrical technique described are compared to measurement results for some cases, and, except for large angles of incidence, the agreement is shown to be good. In concert halls and churches most room surfaces will be acoustically hard, which allows the technique to be used to good advantage.