Coherent acoustic field computations using first-order multiple scattering and the generic sonar model

Abstract

The generic sonar model (GSM) is modified to include, as an option, the computation of the coherent acoustic field in an ocean environment with internal waves. This modification to GSM permits estimation of coherent signal processing performance. GSM computes the acoustic pressure in a horizontally stratified ocean in the absence of environmental inhomogeneities using WKBJ solutions to the Helmholtz equation. Using the first-order multiple scattering approximation and the Garrett and Munk internal wave model, the coherent acoustic field is included in GSM for frequencies from 100 to 10 000 Hz. Results are presented using the modified GSM with internal waves. Comparisons are made with earlier results, which used the parabolic equation method [B. J. Bates and S. M. Bates, J. Acoust. Soc. Am. 82, 2042–2050 (1987)], and GSM without internal waves.