A Study of Underwater Sound Ray Tracing Methodology

Abstract

An operational study has been made of algorithms employed in short base line underwater position location systems. Some important sources of systematic error have been uncovered. The issues studied include isospeed vs. isogradient ray tracing, effect of the depth velocity profile and water layer thickness, approximate vs. exact array tilt corrections, and ray tracing initialization methodology. It is shown that the practice of constant speed extrapolation of depth-velocity information can cause considerable mischief. The best remedy is to measure speed all the way to the bottom. It is further shown that the systematic errors are periodic functions of the azimuth direction of the sound ray from the receiver array. The amplitudes of these functions are greater for the more severely tilted arrays. An alternative algorithm is proposed that reduces these errors by at least an order of magnitude. (JHD)

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Document Details

Document Type
Technical Report
Publication Date
Sep 01, 1990
Accession Number
ADA229666

Entities

People

  • Robert R. Read

Organizations

  • Naval Postgraduate School

Tags

Communities of Interest

  • Air Platforms
  • Sensors
  • Weapons Technologies

DTIC Thesaurus Topics

  • Algorithms
  • Computations
  • Computer Programming
  • Computer Programs
  • Coordinate Systems
  • Engineering
  • Euler Angles
  • Notation
  • Orientation (Direction)
  • Periodic Functions
  • Plastic Explosives
  • Position (Location)
  • Ray Tracing
  • Three Dimensional
  • Two Dimensional
  • Undersea Warfare
  • Underwater Sound

Fields of Study

  • Physics

Readers

  • Adaptive Control and Estimation with Uncertainty in Dynamic Systems.
  • Systems Analysis and Design
  • Wave Propagation and Nonlinear Chaotic Dynamics.