Seabed Geoacoustic Structure at the Meso-Scale

Abstract

The long term science goals of the project are to understand the nature of the seabed at the geoacoustic meso-scale O(100-10:!) m and determine how these structures impact acoustic propagation, diffuse reverberation, and clutter. Several discoveries were made in the course of the project, notably that a) there is a persistent scale, O(0.1) m that controls reverberation in a number of shallow water environments, and b) clutter can be generated by non-discrete, i.e., smoothly and slowly-varying sediment structures (in addition to traditional discrete features, e.g., wrecks). In addition, there were a number of significant advances including: development of measurement techniques/processing to measure meso-scale geoacoustic variability over tens of km with resolution of 0.1 m/7 m in the vertical/lateral dimension; and developing tools to separate frequency-dependent effects so that unbiased estimates of intrinsic attenuation can be made. Even on the mid to outer shelf, substantial lateral variability at the 10 m lateral scale is observed. The underlying processes that lead to that strong variability are not understood at this time.

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Document Details

Document Type
Technical Report
Publication Date
Sep 30, 2014
Accession Number
ADA615977

Entities

People

  • W. Charles (Wilbur) Holland, Jr.

Organizations

  • Pennsylvania State University

Tags

Communities of Interest

  • Autonomy

DTIC Thesaurus Topics

  • Acoustic Measurement
  • Acoustic Phenomena
  • Acoustic Propagation
  • Acoustic Scattering
  • Acoustic Waves
  • Acoustics
  • Attenuation
  • Autonomous Underwater Vehicles
  • Frequency
  • Measurement
  • Reflection
  • Reverberation
  • Scattering
  • Seabed
  • Sediments
  • Shallow Water
  • Water

Readers

  • Acoustical Oceanography.
  • Systems Analysis and Design