Backscatter Analysis from a Smooth Sand Surface: Diffusion Approximation.

Abstract : The development of a model of backscatter from a smooth underwater sediment surface is described. The model includes two components: the propagation of acoustic energy through the water/sediment interface which is governed by wave theory, and randomization of acoustic energy within the interior of the sediment which is approximated by the diffusion equation. With respect to the wave theory, Biot's poroelastic wave propagation theory is used. The model gives predictions of acoustic backscattering strength as a function of grazing angle, grain size, and energy decay rates that can be matched to experimental data.