ASA 130th Meeting - St. Louis, MO - 1995 Nov 27 .. Dec 01

4aUW11. Shallow-water torpedo reverberation data modeling with the comprehensive acoustic system simulation.

Ruth E. Keenan

Sci. Applications Intl. Corp., P.O. Box 658, Mashpee, MA 02649

Henry Weinberg

Naval Undersea Warfare Ctr. Detachment, New London, CT 06320-5594

The comprehensive acoustic system simulation (CASS) was used to track a 30-dB variability in the reverberation time series from 38 torpedo pings within a 4-km[sup 2] area of the shallow-water U.S. Navy SOCAL range. This data set was extremely well modeled with a fairly simple bottom description. A thorough survey of the bottom characteristics in this area showed that the region transitioned from a current-swept rough-rock bottom to a mud-filled depression. The Gaussian ray bundles (GRAB) model, a component of CASS, simulated the acoustic propagation in this range-dependent environment. With the exception of the forward bottom loss for rock, the component scattering models proposed by the Applied Physics Laboratory, University of Washington [APL-UW TR 9407, AEAS 9501, October 1994] were used in the simulation. Twenty-nine interleaving torpedo pings traversed the rough-rock conditions. The model predictions were internally consistent with the data and the environment when a 6-dB value was assumed for the rough-rock forward bottom loss. [Work supported by the Naval Sea Systems Command (PMS-402 and PMS-406) and the Office of Naval Research (ONR-321).]