Accession Number : ADD013733

Title :   Method for Measuring Particle Velocity Using Differential Photodiode Arrays.

Descriptive Note : Patent, Filed 3 May 82, patented 16 Feb 88,

Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON DC

Personal Author(s) : McCullough, James R ; Agrawal, Yogi C

Report Date : 16 Feb 1988

Pagination or Media Count : 4

Abstract : This patent discloses a method for measuring the velocity of a scattering in a moving fluid by examining the spatial structure of the optical field on the detector of a Laser Doppler Velocimeter (LDV). The optical field, after scattering from the laser beam, is a traveling wave of a shape dependent on the detector optics alone. A pair of differential linear arrays are used to find the direction of velocity of the traveling wave and hence that of the scatterer. Furthermore, this method eliminates the Doppler pedestal which requires high pass filter in most of the conventional methods.

Descriptors :   *DETECTORS, *LASER VELOCIMETERS, *PHOTODIODES, *PATENTS, ANTENNA PEDESTALS, ARRAYS, DOPPLER SYSTEMS, FLUIDS, HIGH PASS FILTERS, LASER BEAMS, LINEAR ARRAYS, MEASUREMENT, MOTION, OPTICAL PROPERTIES, OPTICS, PARTICLES, SCATTERING, SPATIAL DISTRIBUTION, TRAVELING WAVES, VELOCITY

Subject Categories : Target Direction, Range and Position Finding
      Test Facilities, Equipment and Methods

Distribution Statement : APPROVED FOR PUBLIC RELEASE