Predicting Time Reversing Array Performance in Shallow Ocean Waters

Abstract

Long-Term Goals: The long term goals of this project are: i) to predict and understand the characteristics of active and passive time reversing array (TRA) performance in shallow water ocean waters, and ii) to deduce the effectiveness of using a TRA for underwater communication and for surveillance of the acoustic characteristics of known or unknown environments. Objectives: This project seeks to quantitatively predict TRA performance in shallow ocean environments. Here performance includes: retrofocus field amplitude, location, size, and longevity; and the correlation of the retrofocused signal with the original signal. The intent is to predict these quantities as a function of signal frequency and bandwidth, source-array range, array orientation, noise level, source motion, array motion, and array configuration in shallow ocean sound channels containing realistic propagation complexities. Such complexities include dynamic random shallow-water internal-waves, noise, bottom losses, and three-dimensional acoustic scattering. The challenge here is to ascertain generic features and scaling laws in the presence of wide natural variability. Such results form the starting point for the design of practical TRA systems. While past work on this project has concentrated on narrowband signals in dynamic [1,2] and noisy [3] environments having weak azimuthal scattering [4], the current effort emphasizes array orientation [5], broadband signals [6,7], the effects of source and array motion, and three-dimensional environments.

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Document Details

Document Type
Technical Report
Publication Date
Sep 30, 2001
Accession Number
ADA626425

Entities

People

  • David R. Dowling

Organizations

  • University of Michigan

Tags

Communities of Interest

  • Energy and Power Technologies
  • Ground and Sea Platforms
  • Materials and Manufacturing Processes

DTIC Thesaurus Topics

  • Acoustic Communications
  • Acoustic Scattering
  • Autonomous Underwater Vehicles
  • Bandwidth
  • Broadband
  • Communication Systems
  • Communications Techniques
  • Environment
  • Frequency
  • Mechanical Engineering
  • Narrowband
  • Shallow Water
  • Surveillance
  • Three Dimensional
  • Underwater Acoustic Communications
  • Underwater Communications
  • Water

Readers

  • Acoustical Oceanography.