LONG TERM GOALS

The ability to predict transmission loss of sound propagating in shallow water is constrained by the knowledge of the geoacoustic properties of the bottom. The long term objectives of this research project are related to the investigation of experimental methods and inversion techniques for estimating parameters of geoacoustic models of the ocean bottom and the associated uncertainties in the model parameter values. The specific goals are to evaluate the performance of geoacoustic inversion techniques that have been developed for use in range-dependent shallow water environments, and synthesize the results obtained for characterizing the seabed from the SW06 and other recent experiments. The wider context of this research is to achieve improved sonar system performance through greater understanding of the physics of the interaction of sound with the ocean bottom. OBJECTIVES The experiments carried out in the ONR SW06 Experiment during August-September 2006 on the New Jersey continental shelf provided high quality data over a broad frequency band from 50 Hz to 20 kHz that can be used for evaluating and comparing the performance of several different techniques. These include matched field inversion, reflection coefficient and bottom loss inversion, phase and group velocity dispersion and wavenumber extraction inversions. This report presents comparisons o