Grumman Aerospace Corporation

Suey Jue, Deceased

Kenneth G Leib

Benjamin J Pernick

Prior art optical image correlators are extremely cumbersome and do not use spatial light modulators. To determine whether an of-interest target is within a scene, the present invention optical correlator uses a laser diode, a spatial light modulator, a holographic lens array, a matched filter array and an inverse transform lens. In particular, the laser diode generates a coherent laser beam, which is expanded and collimated. Information of the of-interest target is encoded thereon by the spatial light modulator. The encoded laser beam is then directed to the holographic lens array, which replicates from the single laser beam a plurality of similar beams. These beams are focused onto a matched filter array having multiple matched filters, the number of which corresponds to the number of incoming beams. If there is a close match between an incoming beam and a corresponding matched filter, a high intensity light is emitted from that particular matched filter toward the inverse transform lens, from when the high intensity beam is focused onto a correlation plane, where the existence of of-interest targets is ascertained.

Optical target recognition system

Prior art optical correlator systems can perform only translation or rotation. Moreover, images obtained from these prior art systems are blurred due to movements of the target. In the present optical correlator system, to compare symbols on a particular frame of a film with predefined symbols stored in a memory, a novel driving mechanism which can both translate and rotate the film is used. The driving mechanism includes a translation device which has a plurality of gears and rollers mounted in a platform within a housing which may be filled with a fluid having an index of refraction corresponding to that of the film. Motors are coupled to the housing for translating and rotating the driving mechanism so that selected symbols on the film may be compared both linearly and rotatively with predefined symbols. The driving mechanism may further be used as an image motion compensator for eliminating blurring caused by target movements.

Growing community of inventors

late of Hicksille, NY, United States of America

Suey Jue, Deceased