Accession Number : AD0775518

Title :   Experiment and Numerical Evaluation of Acoustic Scattering at a Rough Surface.

Descriptive Note : Research rept.,

Corporate Author : WISCONSIN UNIV MADISON GEOPHYSICAL AND POLAR RESEARCH CENTER

Personal Author(s) : Sandness,Gerald A.

Report Date : 02 OCT 1973

Pagination or Media Count : 119

Abstract : The Helmholtz integral is often used as the basis for theories on scattering of acoustic signals from rough surfaces, but several approximations must be made to obtain analytical solutions. Many of the mathematical difficulties in analytical computations can be avoided by numerically evaluating the Helmholtz integral. A numerical technique is described which uses measured values of the acoustic pressure of the incident beam, including the side lobes, thereby removing the uncertainty which normally results from approximating the form of the incident beam. A comparison of numerical, analytical, and experimental results is made for the case of a vertically incident beam and a moderately rough surface. The numerical computations are shown to yield values of the scattered pressure which agree well with experimental data for both rough and smooth surfaces. (Modified author abstract)

Descriptors :   *Acoustic scattering, *Electromagnetic scattering, *Surface roughness, Approximation(Mathematics), Numerical integration, Computer programs

Subject Categories : Acoustic Detection and Detectors
      Acoustics
      Radiofrequency Wave Propagation

Distribution Statement : APPROVED FOR PUBLIC RELEASE