Infering the characteristics of marine sediments from the acoustic response of a known object

Abstract

The acoustic response of an object depends on the surrounding environment. We show here how to take advantage of a known elastic target located near the seabed to infer characteristics of marine sediment. The approach consists of several steps. First, the structural admittance matrix of the elastic object is determined (numerically or experimentally). Then, the Equivalent Source Method (ESM) coupled with a spectral representation of the Green's functions in stratified domains makes it relatively inexpensive in terms of computational time to predict the object acoustic signature in various environments and experimental configurations. The resulting solver takes into account all multiple scattering between target (buried or not), sea floor and sea surface and is not limited to short distances. After presenting the solution to the forward problem we then show several synthetic inversions for sediment characteristics.