Surface Acoustic Scattering Based on the Small Slope Approximation Method

Abstract

The purpose of this paper is to study the acoustic scattering characteristics of a one-dimensional random undulating interface based on the PM wind wave spectrum. The small slope approximation method is currently a more commonly used method for calculating sea surface acoustic scattering. This method is very effective in calculating the acoustic scattering of rough surfaces under the condition that the glancing angle of the incident angle is not particularly small and the surface slope is not particularly large. Therefore, this paper uses a small slope approximation method to calculate the scattering intensity of a one-dimensional random undulating interface. Moreover, most of the current researches on sea surface acoustic scattering use Gaussian spectrum, which does not conform to the real sea surface. Scientists have done many studies on real ocean waves and proposed several more mature ocean spectra. Therefore, this paper adopts the PM wind wave spectrum, uses its statistical characteristics and the small slope approximation method to analyze its variation with the scattering angle and incident frequency. The results show that as the scattering angle gets closer to the direction of specular scattering, the intensity of scattering gradually increases, and reaches the maximum in the direction of specular scattering. As the incident frequency increases, the scattering intensity in the forward scattering direction first increases and then stabilizes, and the scattering intensity in the backward scattering direction first increases and then fluctuates around the same value. The research results are of great significance to the development of underwater acoustic technology and sonar technology.