Accession Number : ADD013239

Title :   System for Remotely Determining Velocity of Sound in Water.

Descriptive Note : Patent, Filed 22 Dec 80, patented 7 Feb 84,

Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON DC

Personal Author(s) : Guagliardo, John L ; Dufilho, Harold L

Report Date : 07 Feb 1984

Pagination or Media Count : 7

Abstract : This patent discloses a system for remotely sensing the velocity of sound in water using Brillouin scattering. A pulsed laser irradiates the water and the scattered light is collected, collimated and passed through a Fabry-Perot interferometer, then to a photomultiplier. The photomultiplier output is digitized. The interferometer is driven by a ramp generator, and the instantaneous voltage corresponds to the point in the frequency domain to which the digitized output corresponds. For each spectrum, a plurality of laser shots is obtained. A register contains the record of each shot, and when full its contents are transferred to a storage medium. A computer reads the storage medium and develops a three dimensional graphic representation the axes of which are frequency, intensity and depth.

Descriptors :   *PATENTS, *LASER VELOCIMETERS, *LIGHT SCATTERING, *ACOUSTIC VELOCITY, PULSED LASERS, UNDERWATER SOUND, REMOTE DETECTORS, FABRY PEROT INTERFEROMETERS, PHOTOMULTIPLIER TUBES

Subject Categories : Optical Detection and Detectors
      Lasers and Masers

Distribution Statement : APPROVED FOR PUBLIC RELEASE