Accession Number : ADA222329

Title :   Inversion of Data for Near-Grazing Propagation Over Rough Surfaces,

Corporate Author : ILLINOIS UNIV AT CHICAGO CIRCLE DEPT OF MATHEMATICS

Personal Author(s) : Lucas, R. J. ; Twersky, V.

Report Date : NOV 1986

Pagination or Media Count : 14

Abstract : Results for the coherent response to a point source irradiating an embossed plane (J. Acoust. Soc. Am. 76, 1847 (1984)) are applied to interpret and invert data obtained by Medwin et al. (J. Acoust. Soc. Am. 76, 1774 (1984)). As emphasized earlier (J. Acoust. Soc. Am. Suppl. 1 74, S122 (1983)), key features arise from interference of elementary components of the corresponding Sommerfeld-type wave system based on the complex error function complement Q. Simplified analytical approximations are presented to emphasize the essential physics, and to facilitate initial estimates of unknown parameters. Refined estimates using Q integral theory are incorporated in graphical results to display primary data trends of the magnitudes and phases as well as the dependence of the incremental dispersion on both range and frequency. Keywords: Reprints. (KR)

Descriptors :   *ACOUSTIC DATA, *INVERSION, APPROXIMATION(MATHEMATICS), COHERENCE, DISPERSING, DISPLAY SYSTEMS, ESTIMATES, GRAPHICS, INTERFERENCE, PATTERNS, PHYSICS, REPRINTS, RESPONSE, SIMPLIFICATION, SOURCES, SURFACE ROUGHNESS.

Subject Categories : Acoustics

Distribution Statement : APPROVED FOR PUBLIC RELEASE