Low-frequency reverberation signal in shallow water in presence of internal waves

Abstract

The reverberation of low-frequency (100–400 Hz) sound in shallow water is considered. It is supposed that reverberation signals are formed by summarizing from circle area (radius about 50 km) as result of sound field backscattering on bottom surface. The developed model of reverberation takes into account mode coupling caused by background internal waves in shallow water and depending on direction of backscattered signal. Influence of internal waves on space-time structure of reverberation signal is considered for two cases: single-modal and multi-modal. The computer simulation shows that internal waves lead to significant temporal fluctuations of reverberation signal in both cases. The results of computer simulation are compared with data of experimental research in the Barents Sea. [Work supported by RFBR, Grants 02-02-16509 and 03-05-64568.]