Improved Laser Velocimetry Detection of Underwater Sound

Abstract

The present invention relates to acoustic wave systems and more particularly to means for detecting of acoustic waves by means of electromagnetic radiation. The detection and measurement of sound using lasers is well known. Essentially, a light beam is caused to pass through a medium, which may be air or water, and detect and process reflections from particles in the medium. These particles will tend to have approximately the same velocity as the particle velocity associated with an acoustic plane wave propagating through the medium. The particle velocity for the plane wave is P/(poc), where P is the pressure amplitude, Po is the density and c is the speed of the sound in the medium. The elapsed time and the Doppler shift of the reflected beam indicate the locations and velocity of the scattering particle.

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Document Details

Document Type
Technical Report
Publication Date
Aug 20, 2001
Accession Number
ADD019981

Entities

People

  • Anthony A. Ruffa

Organizations

  • United States Department of the Navy

Tags

Communities of Interest

  • Air Platforms
  • Energy and Power Technologies
  • Sensors

DTIC Thesaurus Topics

  • Acoustic Impedance
  • Acoustic Propagation
  • Acoustic Waves
  • Detection
  • Detectors
  • Doppler Effect
  • Electromagnetic Radiation
  • Frequency
  • Frequency Bands
  • Laser Beams
  • Light Pulses
  • Measurement
  • Optical Detectors
  • Particles
  • Resonant Frequency
  • Scattering
  • Sound Waves

Fields of Study

  • Physics

Readers

  • Combustion Dynamics and Shock Wave Physics.
  • Electromagnetic Wave Scattering and Antenna Radiation Engineering
  • Optical Physics and Photonics.

Technology Areas

  • Directed Energy