Seabed Characterization by Inversion of Acoustic Data from a Towed Array

The goal of geoacoustic inversion is to estimate environmental parameters from measured acoustic fields from e.g. a towed array. Though the inversion results have some uncertainty, inversion is an efficient technique to estimate environment parameters. Based on the a posteriori probability density of environmental parameters obtained from inversion, we perform statistical estimation of transmission loss (TL) and generate a 90% credibility level envelope or uncertainty band for the TL. This uncertainty band accounts for the inherent variability of the environment not usually contained in sonar performance prediction model inputs, and presents a useful probabilistic description of the environment s variability. Towed arrays are advantageous to fixed systems as they are easy to deploy and the moving ship enables estimation of spatially variable seabed properties. The approach is demonstrated with data obtained from the MAPEX2000 experiment conducted by NATO Undersea Research Centre (NURC) in the Mediterranean Sea in November 2000. Index Terms geoacoustic inversion, seabed characterization, towed array, transmission loss estimation.