Fluctuations of high-frequency sound field in shallow water in the presence of internal waves

Abstract

The structure of space-time fluctuations of a high-frequency (several kHz) sound field in a shallow water waveguide is considered. The sound field fluctuations due to internal and surface waves show different temporal variability. The perturbation theory within the framework of ray description is applied in order to derive some analytical estimation of fluctuations of arrival time and vertical angle distribution of high frequency broadband acoustics signals. The parabolic equation is used for numerical modeling of space-time fluctuations and vertical sound field intensity distribution. The experimental measurements of ocean dynamics from recent acoustic experiments are used as input data in numerical simulation of sound field fluctuations. [Work was supported by ONR and CRDF].