Modeling the Effect of Internal Waves on Long-Range Propagation

Abstract

This project aims to understand the fluctuations in low frequency (100 Hz, for example) acoustical propagation in the ocean over long distances (50 km to thousands of km.), as well as other effects of internal waves and other small-scale variability in the speed of sound. OBJECTIVES The objective is to model results of recent low-frequency, deep-water acoustic-propagation experiments, constraining the model environment from the measurements of those environments. Phenomena such as intensity fluctuations and deep arrivals are of more concern than travel time fluctuations, as the physics of travel time fluctuations is much better understood. APPROACH This project has concentrated mostly on the analysis of environmental data to separate the physical processes leading to sound speed fluctuations, and then to use semi-empirical models of these processes for acoustic propagation calculations. Small-scale internal waves and "spice" are the processes of concern for predictions of fluctuations of intensity and spatial correlations and of the deep arrivals. CTD (conductivity, temperature, depth as measured by pressure) profiles are used to extract the small-scale internal waves and "spice". PE (parabolic equation) calculations have been used up until now to simulate the acoustics, but mode equation techniques are superior for some purposes.

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Document Details

Document Type
Technical Report
Publication Date
Sep 30, 2010
Accession Number
ADA542086

Entities

People

  • Frank S. Henyey

Organizations

  • University of Washington

Tags

Communities of Interest

  • Materials and Manufacturing Processes

DTIC Thesaurus Topics

  • Acoustic Propagation
  • Acoustics
  • Deep Water
  • Environment
  • Equations
  • Frequency
  • Gaussian Processes
  • Intensity
  • Internal Waves
  • Measurement
  • Philippine Sea
  • Physics
  • Physics Laboratories
  • Spectra
  • Travel Time
  • Waves

Fields of Study

  • Physics

Readers

  • Acoustical Oceanography.