ASA 128th Meeting - Austin, Texas - 1994 Nov 28 .. Dec 02

2aUW9. Consistent geoacoustic models in the frequency range 50--5000 Hz.

Charles W. Holland

Peter Neumann

Greg Muncill

Planning Systems, Inc., 7923 Jones Branch Dr., McLean, VA 22102

The process of creating a geoacoustic model begins with the process of defining the dominant mechanisms that control bottom interaction for the frequency range and application of interest. For example, a geoacoustic model that treats the seafloor reflection process might be much simpler than a geoacoustic model which treats bottom interaction (i.e., general bi-static scattering including reflection and backscattering as special cases). The following step is to determine values for the parameters that describe those physical mechanisms of importance. This is typically approached by a combination of direct measurements (e.g., core data), empirical modeling {e.g., Hamilton relations [E. L. Hamilton, J. Acoust. Soc. Am. 68, 1313--1340 (1980)]}, or by inversion the acoustic data. The result can be tested by comparing the geoacoustic model predictions (used as primary inputs to an acoustic model) against measured acoustic data. Geoacoustic model predictions and comparisons with acoustic data and are given for a variety of marine environments. A geoacoustic model that is successfully employed for both seafloor reflection and scattering is demonstrated. [Work supported by the ONR/AEAS Program.]