A unified model for reverberation and submerged target scattering in shallow water

Abstract

A unified model for reverberation and submerged object scattering in a stratified medium is developed from a full-field theory for scattering in a waveguide. The advantage of the unified approach is that it enables consistent predictions to be made of the target-echo-to-reverberation ratio as a function of range and depth. A full-field waveguide scattering theory is especially necessary for shallow-water applications since simpler but approximate methods based on free-space scattering, such as the sonar equation, can be in error by many orders of magnitude depending on target shape, size relative to the wavelength, and environment. The model is applied to determine whether submerged targets can be detected above seafloor reverberation for a variety of water column and sediment types, sonar and target locations, and target shapes and sizes. The model is also applied to determine conditions necessary for discrete geomorphological features of the seafloor and sub-seafloor to be detected above diffuse seafloor reverberation.