A Study of the Operator Expansion Method and its Application to Scattering from Randomly Rough Dirichlet Surfaces

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.

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Document Details

Document Type
Technical Report
Publication Date
Jun 01, 1994
Accession Number
ADA281132

Entities

People

  • Peter J. Kaczkowski

Organizations

  • University of Washington

Tags

Communities of Interest

  • Air Platforms
  • Biomedical
  • Energy and Power Technologies
  • Ground and Sea Platforms

DTIC Thesaurus Topics

  • Acoustic Frequencies
  • Acoustic Scattering
  • Acoustic Waves
  • Acoustics
  • Backscattering
  • Computational Science
  • Diffraction
  • Electromagnetic Scattering
  • Geometry
  • Grazing Angles
  • Monte Carlo Method
  • Physics Laboratories
  • Radar
  • Random Variables
  • Three Dimensional
  • Two Dimensional
  • Wave Propagation

Readers

  • Acoustical Oceanography.
  • Aerospace Engineering.
  • Calculus or Mathematical Analysis