Perturbation theory for scattering of sound from a point source by a moving rough surface in the presence of refraction

Abstract

A general perturbation theory is presented which is valid for small surface waveheights and for acoustic wavelengths of the order of the ocean-surface correlation length. Formal solutions for the perturbed field are given and are specialized, to the second order of approximation, for the case of a random ocean surface. The scattering reduces the intensity of the carrier (source) signal and creates signal sidebands that are not in general symmetric in amplitude about the carrier. A pair of system functions for the signal sidebands is defined. Subject Classification: 30.40, 30.30, 30.25; 20.15.