Broadband Acoustic Backscatter and High-Resolution Morphology of Fish: Measurement and Modeling

Abstract

Remote detection and classification of marine organisms require accurate acoustic scattering models that adequately incorporate organism morphology. Broadband acoustic backscattering measurements, advanced high-resolution imaging of fish morphology using CT scans and phase contrast x-rays (in addition to traditional x-rays), and associated scattering modeling using the images have been conducted involving alewife (Alosa Pseudoharengus), a swimbladder-bearing fish. A greater-than-octave bandwidth (40-95 kHz), shaped, linearly swept, frequency modulated signal was used to insonify live, individual, adult alewife that were tethered while being rotated in 1- degree increments of orientation angle over all angles in two planes of rotation (lateral and dorsal/ventral). These data, in addition to providing the orientation dependence of the scattering over a continuous band of frequencies, were also used (after pulse compression) to identify the dominant scattering features of the fish (including the skull and swimbladder).

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Document Details

Document Type
Technical Report
Publication Date
Jan 01, 2002
Accession Number
ADA409817

Entities

People

  • D. B. Reeder
  • J. Michael Jech
  • Timothy K. Stanton

Organizations

  • Woods Hole Oceanographic Institution

Tags

Communities of Interest

  • Air Platforms
  • Ground and Sea Platforms

DTIC Thesaurus Topics

  • Acoustic Measurement
  • Acoustic Scattering
  • Acoustic Waves
  • Acoustics
  • Aquatic Organisms
  • Backscattering
  • Coordinate Systems
  • Fish
  • Fisheries
  • Frequency Bands
  • Health Services
  • High Resolution
  • Measurement
  • Three Dimensional
  • Transducers
  • Two Dimensional
  • X-Ray Computed Tomography

Fields of Study

  • Physics

Readers

  • Acoustical Oceanography.
  • Aquatic Ecology
  • Control Systems Engineering.