Accession Number : ADA304186

Title :   Fluctuations of the Acoustic Field Bragg Backscattered from Rough Surfaces.

Descriptive Note : Interim technical rept.,

Corporate Author : MCDANIEL (SUZANNE T) BREMERTON WA

Personal Author(s) : McDaniel, Suzanne T.

PDF Url : ADA304186

Report Date : 30 JAN 1996

Pagination or Media Count : 41

Abstract : A rigorous theory of backscattering from slightly rough statistically nonstationary surfaces is developed. The development procedes through the application of two ensemble averages: the first to all realizations of the surface having fixed nonstationary features, and the second over all nonstationary surface characteristics. The resulting theory is applied to acoustic seafloor reverberation, where it is found that nonstationarity must be assumed to obtain agreement with observed reverberation fluctuations. The analysis is further extended to the time domain where it is demonstrated that for Bragg scatter, no reduction in the predicted fluctuations occurs for frequency diverse waveforms, thus providing a method of differentiating Bragg scatter from other nonresonant scattering processes.

Descriptors :   *BACKSCATTERING, *ACOUSTIC SCATTERING, *OCEAN BOTTOM, *BRAGG SCATTERING, WAVEFORMS, SURFACE ROUGHNESS, REVERBERATION, UNDERWATER ACOUSTICS, TIME DOMAIN, FREQUENCY DOMAIN, ACOUSTIC FIELDS.

Subject Categories : Acoustics

Distribution Statement : APPROVED FOR PUBLIC RELEASE