Measuring the characteristics of backscattering of sound on a rough surface in the near-field zone of a phased array

Abstract

The paper presents the results of an experiment on measuring the characteristics of backscattering of sound waves by a rough surface. Measurements were conducted in the near zone of a vertical array, which made it possible with a high degree of accuracy to control the propagation conditions and the angles of incidence of an acoustic wave onto the surface. Tonal signals were emitted in a constant mode at frequencies of 0.5–3.5 kHz. The Doppler spectrum of the scattered signal was analyzed in detail, the spectral component corresponding to Bragg scattering was isolated, and the width of this component was determined. The possibilities of calculating the scattered field using two forms of the sea state spectrum are studied and compared: the two-dimensional spatiotemporal sea state spectrum, which was measured optically, and the conventional one-dimensional time spectrum, measured with a single surveying mark.