Simulation of low-frequency sound propagation in shallow sea with two-dimensional random inhomogeneities

Abstract

A local-mode approach to study low-frequency sound propagation in shallow sea with random inhomogeneities of the sound speed and lossy penetrable bottom has been developed. Two-dimensional inhomogeneities of different scales of fluctuations along the sound propagation track have been considered while the regular part of sound speed presented in the form of several layers including a sea thermocline at the middle depth. Statistical simulation within the framework of adiabatic approximation has been carried out and curves of both average intensity transmission loss and index of acoustic field intensity scintillations are presented. It is shown that dependent on scales of random inhomogeneities and distance of sound propagation in shallow sea environment there will be stochastic waveguide of one or another focal force. With this, there is a change in transmission loss, and acoustical signal fluctuations achieve the great values at ten or more kilometers.