VISAR (Velocity Interferometer System for Any Reflector): Displacement-mode data reduction
A Velocity Interferometer System for Any Reflector (VISAR) is a laboratory tool that measures high velocities by continuously measuring the Doppler shift of laser light reflected from a moving surface. It produces lower output frequencies than a displacement interferometer in which Doppler-shifted laser light from a moving target is mixed with unshifted laser light. To obtain lower frequencies, a VISAR employs a wide-angle Michelson interferometer with a time delay in one leg. Undelayed and delayed light rays are thus mixed to detect the relatively small difference between two Doppler shifts produced by accelerating motion at two slightly different velocities. In most VISAR data reduction programs, the velocity is assumed to be proportional to the interferometer fringe count at any instant. This yields velocity details that are inaccurate over the interferometer delay time. In the examples of this paper, the signal time resolution was shorter than the interferometer delay. The subject of this paper is a data reduction method that uses the displacement information in suitable VISAR signals to recover velocity features that occur during the interferometer delay. 9 refs., 8 figs.
- Research Organization:
- Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
- Sponsoring Organization:
- DOE/DP
- DOE Contract Number:
- W-7405-ENG-36
- OSTI ID:
- 6712986
- Report Number(s):
- LA-UR-90-2321; CONF-900756-15; ON: DE90015027
- Resource Relation:
- Conference: SPIE's international symposium on optical and optoelectronic applied science and engineering exhibit, San Diego, CA (USA), 8-13 Jul 1990
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
42 ENGINEERING
LASER RADIATION
DOPPLER EFFECT
TARGETS
VELOCITY
MEASURING METHODS
ACCELERATION
INTERFEROMETERS
INTERPOLATION
LASERS
PHOTODETECTORS
RECORDING SYSTEMS
REFLECTIVITY
SENSITIVITY
STREAK CAMERAS
SURFACE PROPERTIES
WAVELENGTHS
CAMERAS
ELECTROMAGNETIC RADIATION
MEASURING INSTRUMENTS
NUMERICAL SOLUTION
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
RADIATION DETECTORS
RADIATIONS
440800* - Miscellaneous Instrumentation- (1990-)
440600 - Optical Instrumentation- (1990-)
426002 - Engineering- Lasers & Masers- (1990-)