EP0152186A2
Expired / Lapsed
EP
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Optical correlator
Assignee: STC PLC
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Filing: 1985-01-17
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Granted: —
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Expires: 2005-01-17
Abstract
Abstract A joint transform correlator in which a servo-feedback system (18) is included which employs the correlation signal output to electronically modify the representation of the 'archetype' in the reference scene portrayed in one of the spatial light modulators (12) of the correlator to make it a closer match to any 'quarry' discovered in the investigation scene portrayed in the other spatial light modulator (11).
Inventors
- 👤 Neil Collings
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 13:18
CPC Classifications
G; G06; G06E; G06E3/00; G06E3/001; G06E3/005
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
143 words
A joint transform correlator having first and second spatial light modulators for forming adjacent first and second coherent light phase or contrast images in the input or object plane of the correlator, a dynamic hologram recorder spaced from the object plane, and an intervening first lens or lens system located such that the dynamic hologram recorder lies in the Fourier transform plane of the coherent light images, a coherent light source for illuminating the dynamic hologram recorder, a two-dimensional image receiving photoelectronic transducer, and an intervening second lens or lens system located such that the transducer lies in the Fourier transform plane of the dynamic hologram recorder, characterised in that the second of the spatial light modulators is adapted to be electronically controlled using a servo-feedback system to change its image to maximise the sharpness of the correlation image formed on the transducer.
Claim 2
Dependent Claim
143 words
A joint transform correlator having first and second spatial light modulators for forming adjacent first and second coherent light phase or contrast images in the input or object plane of the correlator, a dynamic hologram recorder spaced from the object plane, and an intervening first lens or lens system located such that the dynamic hologram recorder lies in the Fourier transform plane of the coherent light images, a coherent light source for illuminating the dynamic hologram recorder, a two-dimensional image receiving photoelectronic transducer, and an intervening second lens or lens system located such that the transducer lies in the Fourier transform plane of the dynamic hologram recorder, characterised in that the second of the spatial light modulators is adapted to be electronically controlled using a servo-feedback system to change its image to maximise the sharpness of the correlation image formed on the transducer.
Claim 3
Dependent Claim
31 words
An optical correlator as claimed in claim 1, wherein a holographic correction element is included in the optical path to compensate for extraneous wavefront distortion introduced by the spatial light modulators.
Claim 4
Dependent Claim
29 words
An optical correlator as claimed in claim 1 or 2, wherein the servo-feedback system includes electronic processing means responsive not only to correlation peak amplitude but also to shape.
References Cited (Backward Citations)
No citation records indexed.
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