Geoacoustic inversion on the continental shelf - layered elastic seabeds

Abstract

The prediction of passive low-frequency sonar conditions in shallow water requires knowledge of the composition and geoacoustic parameters of the seabed. Seabed geoacoustic parameters can be estimated by inversion of acoustic data. The use of low-frequency broadband transmission loss data recorded on a single hydrophone in the water column has been studied in this context. A set of range-independent layered elastic seabed environments including some thin-layer cases have been studied by use of synthetic data. It is found that good estimates of key geoacoustic parameters or combinations of such can be obtained by use of this kind of data. Transmission loss data acquired at two Continental Shelf sites are then used for geoacoustic inversion. Improved-match seabed models with parameter estimates in reasonable agreement with data from other geophysical methods are obtained. The results presented support the development of an improved acoustic modelling and prediction capability for the Continental Shelf.