The Ocean-Refraction Bathymetric-Scattering (ORBS) Model

Abstract

The ocean-refraction bathymetric-scattering (ORBS) model is an underwater acoustic model, implemented on the VAX 11/785 and Cray X-MP/24 computers, that uses two-dimensional spatial frequency spectra of ocean bathymetry to estimate the effect, in the ensemble-average sense, of bottom scattering on the coherence of an acoustic signal. The model is designed for a situation (either long-range or short-range) where one bottom interaction dominates the propagation. The principal output of ORBS is a simulation of the beam response of an acoustic array. The calculation works by propagating an 'angular power distribution' (the Fourier transform of the mutual coherence function) along its characteristic curves in the medium. The bottom-interaction calculation is a three-dimensional computation of scattering from a rough bottom described by a two-dimensional power spectral density of bottom heights about a mean slope of arbitrary the computed scattered power accurate to a fraction of 1 dB (when compared with the results from computing the Kirchhoff integral directly).

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Document Details

Document Type
Technical Report
Publication Date
Jul 29, 1988
Accession Number
ADA199534

Entities

People

  • D. H. Berman
  • E. B. Wright
  • J. S. Perkins
  • R. N. Baer

Organizations

  • United States Naval Research Laboratory

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Acoustic Fields
  • Acoustics
  • Arrays
  • Boltzmann Equation
  • Computations
  • Coordinate Systems
  • Differential Cross Sections
  • Frequency
  • Geometry
  • Power Distribution
  • Refraction
  • Roughness
  • Scattering
  • Scattering Cross Sections
  • Simulations
  • Three Dimensional
  • Two Dimensional

Fields of Study

  • Physics

Readers

  • Approximation Theory.
  • Coastal Oceanography
  • Wave Propagation and Nonlinear Chaotic Dynamics.