Target azimuth estimation by means of optical detector arrays

Estimation of a target azimuth by means of arrays of optical detectors is investigated. A maximum likelihood algorithm of estimation is developed, and simpler suboptimum algorithms are described. The performance of the maximum likelihood estimator is analysed. It is shown that for a small detector beamwidth the array accuracy becomes an oscillating function of the target azimuth. The minimum accuracyà depends on the detector beamwidth and onN, the number of detectors in the array. The largerN, the largerÃ; with a givenN, the optimum beamwidth which provides maximum accuracy can be found. The optimum beamwidth implies 100% overlapping of the detector beams, i.e., the semiangle of detector sensitivity should equal the angular separation of the detectors.