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Accession Number:
ADA281132
Title:
A Study of the Operator Expansion Method and its Application to Scattering from Randomly Rough Dirichlet Surfaces
Descriptive Note:
Technical rept.
Corporate Author:
WASHINGTON UNIV SEATTLE APPLIED PHYSICS LAB
Report Date:
1994-06-01
Pagination or Media Count:
188.0
Abstract:
The Operator Expansion OE method, a new approximation introduced by Milder for computing wave scattering from rough surfaces, is applied to acoustic scattering from one-dimensional randomly rough pressure release Dirichlet surfaces. The accuracy of the OE series solution is evaluated through comparison with exact numerical results obtained by solution of an integral equation. Studies of scattering from moderately rough surfaces with a Gaussian spectrum indicate that the first order OE solution is accurate when either small perturbation theory or the Kirchhoff approximation is accurate. The first order OE solution is also accurate in some cases when neither classical method is valid. In this moderate roughness regime, the OE series converges rapidly over all scattering angles for a broad range of incident angles, and numerical studies indicate that rapid convergence is always associated with an accurate solution. As roughness is increased, the OE series solution converges less rapidly overall but remains accurate for a wide range of scattering regimes, including some cases just rough enough to support backscattering enhancement.
Distribution Statement:
APPROVED FOR PUBLIC RELEASE
