Accession Number : AD0783056

Title :   Acoustic Ray Wave Synthesis.

Descriptive Note : Research rept., Jul 73-Jan 74,

Corporate Author : NAVAL UNDERSEA CENTER SAN DIEGO CALIF

Personal Author(s) : Grace,O. D.

Report Date : JUN 1974

Pagination or Media Count : 29

Abstract : An acoustic ray-wave synthesis is developed by combining the wave theory methods of Kirchoff with the ray theory methods of Sommerfeld and Runge. The result is a generalization of the Kirchoff integral formulation of the wave equation in which the kernels are ray theory expressions and in which an additional term appears. The ray theory kernels represent the gross properties of the fields, while the extra term represents scattering by the medium and is the additional field required for an exact solution. This extra term is approximately evaluated for the case of back-scattering by weak random sound speed variations. This evaluation shows that while the source of the scattering lies with the first and second derivatives of the index of refraction, it is the second derivative that is the dominant source of scattering. Further, a back-scattering cross section is derived that agrees with a previously derived results. (Author)

Descriptors :   *Underwater sound, *Signal processing, *Ray tracing, Wave equations, Integral equations, Numerical integration, Acoustic velocity, Acoustic scattering

Subject Categories : Acoustic Detection and Detectors
      Acoustics

Distribution Statement : APPROVED FOR PUBLIC RELEASE