Final Report on Contract N00014-83-C-0303

Abstract

Tasks on this contract focused on understanding the coherence losses incurred by bottom-retained signals due to three mechanisms: sub-bottom roughness, random inhomogeneities in the sediment column, and partial reflections from near-surface layering in the sediment. Work in the first area is continuing and two as-yet-unpublished references are included here to document the status of that effort. The coupled-mode, master-equation model for spatial coherence developed by Dozier has been applied to analyze coherence data acquired in BEARING STAKE and in shallow water. The effects of near-surface layering in sediments produces a loss in frequency coherence i.e., a time spread of the signal) and anomalous bottom-loss behavior. Keywords: Ocean acoustics, propagation, scattering theory, seafloor geology.

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Document Details

Document Type
Technical Report
Publication Date
Apr 01, 1985
Accession Number
ADA155559

Entities

People

  • C. W. Spofford

Organizations

  • Leidos

Tags

Communities of Interest

  • Advanced Electronics
  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Bottom Bounce
  • Bottom Loss
  • Data Processing
  • Diffraction
  • Frequency
  • Geometry
  • Grazing Angles
  • Losses
  • Measurement
  • Power Spectra
  • Reflection
  • Reflectors
  • Refraction
  • Scattering
  • Seabed
  • Sediments
  • Statistics

Readers

  • Acoustical Oceanography.