Improved Laser Velocimetry Detection of Underwater Sound
Patent Application, filed 20 Aug 2001
DEPARTMENT OF THE NAVY WASHINGTON DC
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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 Ppoc, 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.
- Acoustic Detection and Detectors
- Fluid Mechanics