Backscattering of acoustic waves by randomly rough surfaces of elastic solids immersed in water

Abstract

In this paper we study the angular variations of the mean total intensity of ultrasonic waves backscattered by randomly rough surfaces of elastic solids immersed in water. The potential method constitutes the starting point of the theoretical approach. The calculations have been done for a normal distribution of heights and a Gaussian autocorrelation function. The roughness of the samples varies from 8 to 110 μm. The experiments have been done at discrete frequencies up to 10 MHz such that the roughness parameter g( = k21h2γ2) has values ranging from 10−2 to 90. A comparison of the experimental curves and theoretical calculations shows good agreement for incident angles of 40° or less. Another significant feature of this experiment is the increase of the backscattered intensity at the Rayleigh angle for k1 h<1.