Perturbation theory applied to sound scattering from a rough sea-floor

Abstract

Perturbation theory is applied to acoustic scattering from a rough sedimental sea-floor. Realistic

boundary conditions are used, i.e. continuity of pressure and the normal component of particle

velocity. The scattering strength as a function of grazing and azimuthal angle of incident and scattered energy is derived, depending on acoustic frequency, the two-dimensional roughness spectrum of the sea-floor and the ratios of sound velocity and density of the sediment to water. For the special case of backscattering, theoretical scattering coefficients are compared with measured data from the literature. Under reasonable assumptions on the sea-floor parameters, good agreement between theory and measurement can be achieved.