Coherent backscattering effect from mid‐frequency reverberation measurements in shallow‐water.

Abstract

The coherent backscattering (or backscattering enhancement) effect is a persistent interference effect which occurs between waves propagating in random media such as randomly distributed scatterers and rough surfaces. Previous experimental and theoretical studies in optics, acoustics, or seismology have demonstrated that the coherent backscattering results in a doubling of the recorded intensity reflected exactly in the backward direction with respect to any other direction. We will present experimental observations of the coherent backscattering effect from mid‐frequency reverberation data (3–4 kHz) collected in shallow water off the west coast of Italy using various sensor array configurations. This demonstrates the presence of coherent effects in shallow water reverberation recordings from rough sea‐beds. Hence, coherent reverberation effects need to be accounted for to obtain accurate predictions of sea clutter levels. Furthermore, accurate rendering of the coherent backscattering effect could be used to simply verify and validate physics‐based undersea clutter models. Practical implementation for the design of active sonar systems will be discussed. [Work supported by ONR, Code 321.]