OPTICAL IMPLEMENTATION OF A NOVEL ACCURATE-LOCATION RADAR AND SONAR SIGNAL PROCESSOR

An optical implementation is considered for a novel system, recently invented by the author, for accurately locating objects, relatively close to an array, from distributed backscatter. Processing is partitioned into handling scatterers in annuli rather than in pie-shaped regions as in conventional systems that use beamforming followed by matched filtering. The advantages of the new design are discussed. Precomputing a matrix containing geometric and transmission pulse information leaves only matrix-vector computations to be performed in real time. An optical processor is proposed because a large number of these computations must be performed in real time and because optics is well suited to matrix-vector computation. Experimental results are shown for 100 by 100 matrix-vector multiplication with a new device, a spatial light rebroadcaster (SLR). A method of constructing an optical sonar is proposed using the new concept and an optical matrix-vector multiplier. Much faster devices would be required for the method to be practical for a radar processor because of the much higher sampling rates.