Accession Number : AD0742465

Title :   An Expansion Technique for Rendering the WKBJ Method Uniformly Valid.

Descriptive Note : Technical rept.,

Corporate Author : SACLANT ASW RESEARCH CENTRE LA SPEZIA (ITALY)

Personal Author(s) : Lauvstad,Vetle R.

Report Date : 15 DEC 1971

Pagination or Media Count : 40

Abstract : A method is proposed for obtaining a uniformly valid approximation to the solution of the wave equation in a stratified medium. The method differs from those previously used in that it is not based on ordinary asymptotic expansions but employs a multiple scale approach together with matched asymptotic expansions. The method represents an advance over conventional methods in permitting its range of validity to include transition points. It also, in principle, lends itslef particularly well to iteration. For illustration the procedure has been applied to the barrier transmission problem and the problem of trapped wave modes in a SOFAR channel. (Author)

Descriptors :   (*UNDERWATER SOUND, WAVE FUNCTIONS), SOUND TRANSMISSION, ANALYTIC GEOMETRY, WAVE FUNCTIONS, ASYMPTOTIC SERIES, COMPLEX VARIABLES, PARTIAL DIFFERENTIAL EQUATIONS, NUMERICAL ANALYSIS, APPROXIMATION(MATHEMATICS)

Subject Categories : Physical and Dynamic Oceanography
      Acoustic Detection and Detectors
      Acoustics

Distribution Statement : APPROVED FOR PUBLIC RELEASE