Recursive Ray Acoustics for Three-Dimensional Sound-Speed Profiles

Abstract

A comparison of simple recursive ray acoustics algorithm versus a ray acoustics algorithm based on solving a system of first-order ordinary differential equations was conducted. The recursive ray acoustics (RRA) algorithm was found to be accurate and relatively fast. The RRA algorithm is capable of handling sound speed as a function of all three spatial coordinates, and this capability was demonstrated. Two separate methods of representing a sound-speed profile (SSP) based on data points were examined: Akima cubic spline and spatial Fourier series (SFS). The SFS representation encountered difficulties in accurately modeling SSPs. Various techniques were applied to improve the SFS sound speed representation. While accurate sound-speed fits were eventually achieved, difficulties remained in the SFS modeling of first and second-order derivatives of the sound-speed data. The RRA algorithm was tested using the SFS sound-speed representation and found to be significantly inaccurate. A demonstration was conducted of the ability of the SFS sound-speed representation to incorporate randomness in the SSP.

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Document Details

Document Type
Technical Report
Publication Date
Sep 01, 1991
Accession Number
ADA245613

Entities

People

  • F. W. Polnicky

Organizations

  • Naval Postgraduate School

Tags

Communities of Interest

  • Air Platforms
  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Acoustics
  • Algorithms
  • Angle Of Arrival
  • Computational Science
  • Computer Simulations
  • Computers
  • Differential Equations
  • Equations
  • Fourier Series
  • Plastic Explosives
  • Reflection
  • Seabed
  • Simulations
  • Sine Waves
  • Three Dimensional
  • Travel Time
  • Waves

Readers

  • Aerospace Engineering
  • Finite Element Method (FEM) for solving Partial Differential Equations (PDEs)
  • Wave Propagation and Nonlinear Chaotic Dynamics.