On spatial structure of the wave field in a vertical section of a deep water acoustic waveguide

Institute of Applied Physics RAS - Nizhny Novgorod, Russia

Received: 17 April 2018
Accepted: 6 September 2018

Abstract

The spatial structure of the wave field excited by a tonal point source in an underwater acoustic waveguide with random sound speed fluctuations is analyzed. This is done using an approach in which the field is approximated by a sum of components formed by contributions of narrow beams of rays. These components fluctuate less than the total field and, therefore, they are called stable. Each ot them can be isolated from the total field recorded by a long vertical antenna, using the coherent state expansion developed in quantum mechanics. An approximate analytical expression is obtained for the correlation matrix of the superposition of several stable components. The applicability of this equation is confirmed by the results of Monte Carlo simulation. The simulation has confirmed the theoretical prediction that nearly the same stable components can correspond to the sound speed fluctuations with completely different correlation functions.