Inferring the characteristics of marine sediments from the acoustic response of a known, partially buried object

We investigate the feasibility of using a known elastic target located near the seabed for the purpose of inferring characteristics of marine sediment. In the problem considered the object position and its burial depth are not known with precision. First, the admittance matrix of the elastic object is determined (numerically or experimentally) over a wide frequency range in the structural acoustic regime. Then, the equivalent source method (ESM) coupled with a spectral representation of the Green's functions in stratified domains is used 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 several synthetic inversions for sediment characteristics are shown. They are based upon a resonance-based misfit function we describe. The Bayesian procedure also infers object burial and source-object range, broadening its range of application. (C) 2022 Acoustical Society of America.

Automated summary

The feasibility of using a known elastic target near the seabed to infer characteristics of marine sediment is investigated in this study. The approach involves determining the admittance matrix of the elastic object numerically or experimentally and predicting the object's acoustic signature using the equivalent source method coupled with a spectral representation of the Green's functions. Synthetic inversions are performed to infer burial depth and source-object range.