Accession Number : ADA324236

Title :   Scattering from Elastic Sea Beds: First-Order Theory.

Descriptive Note : Final rept. 24 Oct 94-30 Nov 96,

Corporate Author : WASHINGTON UNIV SEATTLE APPLIED PHYSICS LAB

Personal Author(s) : Jackson, Darell R. ; Ivakin, Anatoliy N.

PDF Url : ADA324236

Report Date : 16 AUG 1996

Pagination or Media Count : 29

Abstract : A perturbation model for high frequency sound scattering from an irregular elastic sea bed is considered. The sea bed is assumed homogeneous on the average and two kinds of irregularities are assumed to cause scattering: (1) roughness of the water-sea bed interface and volume inhomogeneities of the sediment mass density and (2) the speeds of compressional and shear waves. The first order small perturbation approximation is used to obtain expressions for the scattering amplitude and bistatic scattering strength. The angular dependence of the scattering strength is calculated for sedimentary rock and the influence of shear elasticity is examined by comparison with the case of a fluid bottom. Shear effects are shown to be strong and complicated.

Descriptors :   *PERTURBATION THEORY, *ACOUSTIC SCATTERING, *OCEAN BOTTOM, HIGH FREQUENCY, ACOUSTIC WAVES, SURFACE ROUGHNESS, BACKSCATTERING, PERTURBATIONS, ACOUSTIC ABSORPTION, UNDERWATER ACOUSTICS, SEDIMENTS, SECONDARY WAVES, BORN APPROXIMATIONS, SEDIMENTARY ROCK, COMPRESSION WAVES.

Subject Categories : Acoustics
      Operations Research

Distribution Statement : APPROVED FOR PUBLIC RELEASE