Optics: measuring and testing – Velocity or velocity/height measuring – With light detector
Patent
1981-10-14
1984-09-11
Buczinski, S. C.
Optics: measuring and testing
Velocity or velocity/height measuring
With light detector
356 28, G01P 336
Patent
active
044706960
ABSTRACT:
Reflections, having positive and negative Doppler frequency shifts, from a laser beam directed at a moving surface are passed through spatial filters, combined by a beam splitter, and focussed on an observation plane of a photodetector to provide a fringe pattern having an amplitude variation frequency responsive to the velocity of the moving surface. The laser beam may be a single beam directed substantially perpendicularly to the moving surface, or the laser beam may be divided into two beams angled toward the surface, one beam impinging with the direction of motion of the surface and the other beam impinging against the direction of motion. When two impinging beams, split from a common beam, are utilized, different polarizations and beam impingement points on the surface may be used to provide beam isolation between the beam signals. Homodyne detection with single frequency lasers is used. With multi-mode lasers emitting two separate frequencies of radiation, heterodyne detection may be used to provide better resolution at low surface velocities.
REFERENCES:
patent: 3419330 (1968-12-01), Schneider
patent: 3432237 (1969-03-01), Flower et al.
patent: 3604804 (1971-09-01), Penney et al.
patent: 3915572 (1975-10-01), Orloff
patent: 4168906 (1979-09-01), Schwiesow
G. Stavis, TNB, vol. 8, #4, 1965 by GPL Div. of General Precision Inc.
"Laser Doppler Velocimeter" Brochure, Cambridge Physical Science, Survey & General Instr. Co. Ltd., Faircroft Way, Edenbridge, Kent, U.K.
W. J. Yanta et al., Agard Conf. Proc. #193 on Applications of Non-Intrusive Instr. in Fluid Flow Research, France (May 3-5 '76).
A. V. Vasil'ev et al., Sov. J. Quantum Electron, vol. 10, #11, Nov. 1980, p. 1466.
L. E. Drain, Laser Focus, 10-1980, pp. 68-73.
R. A. Flower, IEEE Conf. Record of 1969 4th Annual Meet. of IEEE Industry & General Applications Group, Oct. 10-16, 1969, pp. 307-314.
Buczinski S. C.
Systems Research Laboratories Inc.
LandOfFree
Laser doppler velocimeter does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Laser doppler velocimeter, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Laser doppler velocimeter will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1192320