
Accession Number : AD0693115
Title : CORRELATION OF ACOUSTIC SIGNALS SCATTERED AT A ROUGH SURFACE.
Descriptive Note : Research rept.,
Corporate Author : WISCONSIN UNIV MADISON GEOPHYSICAL AND POLAR RESEARCH CENTER
Personal Author(s) : Clay,C. S.
Report Date : JUL 1969
Pagination or Media Count : 52
Abstract : The cross correlation and covariance of the acoustic signals reflected from a statisticallyrough surface is given. The transition from small roughness to large roughness if given for a randomly corrugated surface. The sound reflected and scattered at each subarea were separated into coherent and incoherent components. It was necessary to add the coherent components from the subareas coherently. The incoherent components were added incoherently. Numerical examples are given to show the magnitude of the signals scattered from the subareas. The covariance of signals observed at a pair of receivers are given as a function of the separation. The conditions of applicability of the theory to a geophysical problem have shown that: (1) The upper limit on the size of subareas is given by the lambda/8 criteria for the plane wave approximation. (2) The lower limit is given by the requirement that the dimensions of the subarea be many correlation distances of the rough surface. (3) Far field conditions require that the source and receiver be many acoustic wave lengths from the surface. (Author)
Descriptors : (*OCEAN BOTTOM TOPOGRAPHY, *UNDERWATER SOUND), UNDERWATER SOUND SIGNALS, SURFACE ROUGHNESS, SCATTERING, CORRELATION TECHNIQUES, REFLECTION
Subject Categories : Physical and Dynamic Oceanography
Acoustics
Distribution Statement : APPROVED FOR PUBLIC RELEASE