Results 261 to 270 of about 277,211 (280)

Optical Correlation Techniques

1974
Abstract : The design of a radiometric experiment is described which provides a laboratory model for implementation of the optical correlation technique. The radiometer has provision for alternately viewing the source directly and through a gas absorption cell.
Andrew Tomlinson, Arthur Engelman
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Real-time optical scanning correlator

Applied Optics, 1984
A real-time large-capacity rapid-scanning optical correlator utilizing a rotating grating concept is described. We have shown that the proposed optical scanning correlator (OSC) is capable of processing large-capacity optical memories with rapid spectrum scanning.
F T, Yu, X, Lu
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Unconventional optical correlators

SPIE Proceedings, 1990
Optical inforriation processing has received much attention since the sixties. The parallel nature of optical systens, their inherently large spacebandwidth product and real-time processing capacity has led to the development of meny syst&me and techniques for opt ical inforntion processing and optical computing.
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Optical correlation [PDF]

, 1974
A survey is given of the most common types of coherent optical correlators, which are classified as spatial plane correlators, frequency plane correlators and special reference correlators. Only the spatial plane correlators are dealt with rather thoroughly.
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Quadratic correlation filters for optical correlators

SPIE Proceedings, 2003
Linear correlation filters have been implemented in optical correlators and successfully used for a variety of applications. The output of an optical correlator is usually sensed using a square law device (such as a CCD array) which forces the output to be the squared magnitude of the desired correlation.
Abhijit Mahalanobis, Robert R. Muise, Bhagavatula V. K. Vijaya Kumar   +2 more
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Light utilization in optical correlators

Applied Optics, 1982
An analysis is made of the overall light efficiency in a coherent optical correlator. The results are applied to a matched filter and an inverse filter. Kogelnik's coupled wave theory is applied to analyze the diffraction efficiency of a filter recorded on a high-efficiency phase medium such as dichromated gelatin.
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Minimum noise and correlation energy optical correlation filter

Applied Optics, 1992
A new distortion-invariant optical correlation filter to produce easily detectable correlation peaks in the presence of noise and clutter and to provide better intraclass recognition is presented. The basic ideas of the minimum variance synthetic discriminant function correlation filter (which minimizes noise variance in the output correlation peak ...
G, Ravichandran, D, Casasent
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Optical Correlation Using Diffuse Objectsf

Applied Optics, 1973
A technique is discussed whereby one can optically obtain either the autocorrelation or cross-correlation for real, diffuse object arrays using a single lensless Fresnel hologram. The use of diffuse objects yields, with some loss of resolution, an increase in the effective dynamic range of the process. Theoretical analysis of the process indicates that
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Novel Hybrid Optical Correlator: Theory and Optical Simulation

Applied Optics, 1975
The inverse transform of the product of two Fourier transform holograms is analyzed and shown to contain the correlation of the two images from which the holograms were formed. The theory, analysis, and initial experimental demonstration of the feasibility of a novel correlation scheme using this multiplied Fourier transform hologram system are ...
D, Casasent, R L, Herold
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Optical Correlation of Fresnel Images

Applied Optics, 1968
A real-time optical correlator is described that uses an ultrasonic light modulator (ULM) in conjunction with an amplitude mask or replica of the signal to achieve linear, phase-coherent detection, without need for high quality optics. When the mask is placed in a Fresnel image plane of the ULM, optimum correlation and collinear heterodyning are ...
G, Meltz, W T, Maloney
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