Accession Number : ADA327666

Title :   Final Technical Report on ONR Contract N00014-96-1-0987 (Catholic Univ. of America).

Descriptive Note : Final technical rept.,

Corporate Author : CATHOLIC UNIV OF AMERICA WASHINGTON DC

Personal Author(s) : Beran, M. J.

PDF Url : ADA327666

Report Date : 15 JUL 1997

Pagination or Media Count : 43

Abstract : The objectives of this AASERT grant effort were (1) to incorporate an absorptive bottom into the study of mode energy transfer and decay induced by volume scattering in a shallow channel and (2) to incorporate a piecewise linear sound speed profile into the study of mode energy transfer and decay induced by volume scattering in a shallow channel. Both objectives have been achieved. The introduction of an absorptive bottom generates an additional diffusion term in the coherence range-evolution differential equation and qualitatively changes the nature of the solution. The piecewise linear sound speed profile produces vertical mode wave equation solutions which are Bessel functions with pure imaginary order and pure imaginary argument. These Bessel functions are closely related to the Airy functions Ai and Bi, which are used in their representation. Final results of this effort will be found in Mr. Barnard's doctoral dissertation, which should appear early in 1998.

Descriptors :   *ACOUSTIC SCATTERING, *ACOUSTIC VELOCITY, *UNDERWATER SOUND SIGNALS, MATHEMATICAL MODELS, LINEAR SYSTEMS, ACOUSTIC WAVES, ENERGY TRANSFER, SHALLOW WATER, ACOUSTIC ABSORPTION, UNDERWATER ACOUSTICS, CHANNELS(WATERWAYS), WAVE EQUATIONS, BESSEL FUNCTIONS.

Subject Categories : Acoustics

Distribution Statement : APPROVED FOR PUBLIC RELEASE