Spatio-Temporal Characterization of Bio-Acoustic Scatterers in Complex Media

Abstract

Characterization of biologically-induced ocean reverberation features is key to effectively parametrize acoustic models and thus ultimately improve the detection performance of long-range SONAR systems. In particular, scattering from fish schools can significantly contribute to volume reverberation in the open ocean measured by mid-frequencies tactical SONAR (1kHz-10kHz), especially if the resonance frequencies of the fish air-filled swim bladder is excited. Furthermore, multiple scattering effects from the incident acoustic wave and the collective arrangement of fish lead to complicated frequency response functions. The bio-acoustics properties of the fish body and geometry can also contribute to the scattering response and can be incorporated into an accurate scattering model. The objective of this research is to characterize the relevant spatial and temporal scales of bio-acoustic scatterers generating ocean reverberation to effectively parametrize acoustic models and improve the detection performance of long-range SONAR systems. To do so, we will first develop an efficient modeling technique predict the scattered fields from large fish schools (which can cause especially high false-alarm rate for mid-frequency SONAR systems.), which readily account for the fish acoustic properties, school s spatial configuration and multiple scattering effects.

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Document Details

Document Type
Technical Report
Publication Date
Sep 30, 2012
Accession Number
ADA575088

Entities

People

  • Karim G. Sabra

Organizations

  • Georgia Tech

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Acoustic Properties
  • Acoustic Waves
  • Acoustics
  • Band Gaps
  • Detection
  • Dispersion Relations
  • Eigenvalues
  • Elastic Waves
  • Energy Bands
  • Engineering
  • Frequency
  • Mechanical Engineering
  • Physical Properties
  • Resonant Frequency
  • Scattering
  • Three Dimensional
  • Waves

Readers

  • Acoustical Oceanography.