Definition and measurement of random-incidence scattering coefficients

This paper describes the definition and two methods for measuring scattering coefficients of rough surfaces. In both cases, impulse responses are determined for various orientations of a sample surface. After phase-locked superposition of a sufficient number of impulse responses, the coherent reflected sound energy is obtained. It is identical with the zero-order lobe of the reflection pattern — the specularly reflected part. Considering the totally reflected sound energy, the scattering coefficients can be calculated. The results of the reverberation chamber measurements are scattering coefficients for random sound incidence. Both methods are discussed and experimental results, obtained by scale model measurements, are shown.