Random matrix theory for an adiabatically-varying oceanic acoustic waveguide

Abstract

Problem of sound propagation in the ocean is considered. A novel approach of K. Hegewisch and S. Tomsovic for statistical modelling of acoustic wavefields in the random ocean is examined. The approach is based on construction of a wavefield propagator by means of random matrix theory. It is shown that this approach can be generalized onto acoustic waveguides with adiabatic longitudinal variations. Efficient generalization is obtained by means of stepwise approximation of the propagator. Accuracy of the generalized approach is confirmed numerically for a model of an underwater sound channel crossing a cold synoptic eddy. It is found that the eddy leads to substantial suppression of sound scattering.

Random Matrix Theory for Sound Propagation in a Shallow-Water Acoustic Waveguide with Sea Bottom Roughness

“…The key idea of the approach based on random matrix theory is to represent matrix elements A mn as random Gaussian variables whose variance is determined by variance of the integral (26). This approach is well developed in the case of deep-water acoustic waveguides with volume inhomogeneities, when the propagator is nearly unitary [18,19,27,31].…”

“…The case of nonlinear internal waves was considered in [28][29][30]. In [31], this approach was generalized onto the case of waveguides with adiabatic longitudinal variations. The propagator taking into account temporal variability of the medium was considered in [5].…”