Bottom Sediment Effects in a Numerical Parabolic Equation Ensemble Average Propagation

Abstract

A method of numerical computing average pressure for an ensemble has been developed using a normal mode analysis of the parabolic equation(1). It has been used to compute the transmission loss and phase for the average solutions in the continuous wave case where the vertical variation is smoothly varying. In this paper an alternative choice of basis functions allows one to consider sound velocity profiles with discontinuities while preserving numerical convergence. These discontinuities arise when the sound velocity profile makes a rapid jump between layers of differing speeds. Such a difference occurs between the water column and higher velocity fluid bottoms which model sediment layers. Calculations using energy loss due to sediment penetration allow better estimates of attenuation.... Acoustic scattering, shallow water, waveguide propagation.

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Document Details

Document Type
Technical Report
Publication Date
Jan 01, 1993
Accession Number
ADA267672

Entities

People

  • Roger M. Oba

Organizations

  • United States Naval Research Laboratory

Tags

DTIC Thesaurus Topics

  • Abstracts
  • Acoustic Scattering
  • Acoustics
  • Algorithms
  • Applied Mathematics
  • Attenuation
  • Continuous Waves
  • Convergence
  • Differential Equations
  • Eigenvalues
  • Eigenvectors
  • Equations
  • Frequency
  • Military Research
  • Scattering
  • Shallow Water
  • Wave Propagation

Readers

  • Finite Element Method (FEM) for solving Partial Differential Equations (PDEs)
  • Oceanography.
  • Plasma Physics / Magnetohydrodynamics