Applications of Fresnel-Kirchhoff Diffraction Theory in the Analysis of Human-Motion Doppler Sonar Grams

Abstract

Observed human-gait features in Doppler sonar grams are explained by using the Boulic-Thalmann (BT) model to predict joint angle time histories and the temporal displacements of the body center of mass. Body segments are represented as ellipsoids. Temporally dependent velocities at the proximal and distal end of key body segments are determined from BT. Doppler sonar grams are computed by mapping velocity-time dependent spectral acoustic-cross sections for the body segments onto time-velocity space, mimicking the Short Time Fourier Transform used in the Doppler sonar processing. Comparisons to measured data indicate that dominant returns come from trunk, thigh and lower leg.

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Document Details

Document Type
Technical Report
Publication Date
Nov 01, 2010
Accession Number
ADA535180

Entities

People

  • James J. Sabatier
  • Marshall Bradley

Organizations

  • United States Army Research Laboratory

Tags

Communities of Interest

  • Air Platforms
  • C4I

DTIC Thesaurus Topics

  • Acoustic Scattering
  • Amplitude
  • Bodies
  • Body Regions
  • Cartesian Coordinates
  • Coordinate Systems
  • Diffraction
  • Doppler Radar
  • Doppler Sonar
  • Ellipsoids
  • Frequency
  • Geometry
  • National Security
  • Radar
  • Scattering
  • Scattering Cross Sections
  • Sonar

Readers

  • Acoustical Oceanography.
  • Approximation Theory.
  • Electromagnetic Wave Scattering and Antenna Radiation Engineering

Technology Areas

  • Space