Computer simulation of acoustic wave scattering from rough surfaces

Abstract

Describes the computer simulation of acoustic wave scattering from rough surfaces. A moving average is performed on a set of uncorrelated random numbers giving a set of random correlated numbers representing the height of a rough surface at intervals along the surface. The distribution of the initial data, together with the correlation of the moving average weights, determines the statistics of the generated surfaces. Surfaces are rough in one direction only, i.e. 'furrowed', with random heights and spacings of the furrows. The scattering of acoustic waves from these surfaces is studied using Kirchhoff theory. This gives an expression for the total wave field at any surface point in terms of the local surface height and gradient. The Helmholtz scattering integral is then evaluated over the surface by summing the contributions from each surface point. This gives the amplitude or intensity of the far-field scattered wave.