Accession Number : ADA307870

Title :   Progress Report ONR Number: NOO014-94-1-O201, 1 January 1995 - 30 June 1995,

Corporate Author : CATHOLIC UNIV OF AMERICA WASHINGTON DC DEPT OF ELECTRICAL ENGINEERING

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

PDF Url : ADA307870

Report Date : 30 JUN 1995

Pagination or Media Count : 6

Abstract : In this period the paper 'Combined volume and surface scattering in a channel using a model formulation' by M.J. Beran and S. Frankenthal was presented at the May 1995 ASA meeting. The paper has been submitted for publication to the J. Acoust. Soc. Amer. A second paper entitled 'Data analysis to determine vertical and horizontal correlation lengths of the random index-of-refraction fluctuations in a channel' by T. Barnard and M.J. Beran was also presented at the May ASA meeting. In preparation for calculations in channels with linear sound-speed profiles, programs have been written to calculate the necessary eigenvalues and eigenfunctions. We are also in the process of generalizing the equations governing the transverse scattering in channels. As a first step we have derived the spectral coherence equations for wide angle scattering in an unbounded medium to see the effect of the wide angle scattering. Finally, we considered the equations governing the two-frequency coherence function needed to calculate the propagation of time-dependent signals.

Descriptors :   *ACOUSTIC SCATTERING, *UNDERWATER ACOUSTICS, *ACOUSTIC VELOCITY, MATHEMATICAL MODELS, TIME DEPENDENCE, ACOUSTIC WAVES, NUMERICAL ANALYSIS, REFRACTIVE INDEX, EIGENVECTORS, EIGENVALUES, BACKSCATTERING, SHALLOW WATER, CORRELATION, WAVE PROPAGATION, APPROXIMATION(MATHEMATICS), SPECTRUM ANALYSIS, SEA WATER, ACOUSTIC DATA, CHANNELS(WATERWAYS), ACOUSTIC FIELDS, ACOUSTIC IMPEDANCE, ACOUSTIC REFRACTION.

Subject Categories : Acoustics

Distribution Statement : APPROVED FOR PUBLIC RELEASE