Reconstructing the seafloor properties from acoustic reflection data

Abstract

The determination of the structure of the seafloor using measurements of the acoustic reflected power is an important inverse hydroacoustic problem with many applications in ocean geophysics. A realistic description of the seafloor includes many sedimentary layers over a harder substrate. Assuming that a rough estimation of the thicknesses of the various layers is available (by suitable subbottom profiling) the important thing is to recover the properties of the various layers, that is, the density, the sound velocity, and the attenuation coefficient. A simple scheme for the reconstruction of the seabottom is presented based on the assumption that reliable reflection coefficient measurements from a broadband acoustic source are available. The scheme is based on a systematic variation of the geoacoustic parameters of a background bottom model, so as the calculated reflection coefficient converges to the measured data. It is shown that data from various frequencies are necessary in order to obtain satisfactory results. [Work supported by EEC/MAST program.]