ASA 129th Meeting - Washington, DC - 1995 May 30 .. Jun 06

4pUW6. Preliminary study of the semi-empirical geoacoustic (SEGA) model for bottom reverberation.

Sean M. Reilly

Tracor Appl. Sci., Inc., Anal. and Simul. Dept., 35 Thomas Griffin Rd., New London, CT 06320

Standard bottom reverberation models such as Lambert's rule and perturbation theory assume that scattering from the rough water/bottom interface is the dominant mechanism at all sonar frequencies. However, direct path bottomscattering strength measurements by the Critical Sea Test (CST) program in the 100- to 1000-Hz frequency range suggest that volume scattering from within the sediments may be the dominant reverberation mechanism in many applications. The CST program has been actively investigating a number of new bottom reverberation models which include scattering from within the sediments [Mourad et al., APL/UW Tech. Rep. No. 9107 (1991); Holland et al., 3247(A) (1994)]. Using a combination of elements from these prior techniques, the Semi-Empirical Geoacoustic (SEGA) model for bottom reverberation is used to extrapolate geoacoustic survey measurements into general-purpose reverberation predictions. This presentation summarizes the results of a preliminary 3-month study which explored the viability of this new model using direct path bottom reverberation measurements from CST-5. [Work supported by SPAWAR.]