Abstract: A laser beam is projected from either an underwater body or an overhead support platform, with the laser energy being detected by the other piece of apparatus using a photo detector. Either the projecting or the receiving optics is servo driven to maximize the light energy received by the photo detector. The relative position of the underwater body with respect to the support platform, typically a tracking aircraft, is determined by measuring the position of a driven element laser or photo detector, in either one or two planes, i.e., two or three dimensions, to provide a measure of the trailing distance and when desirable, the lateral offset distance.

Abstract: Apparatus which automatically detects targets of interest in line scanned amplitude modulated data systems such as side scan radar or sonar. The apparatus examines a received signal for target highlights followed by a target shadow of a certain length, depending upon range. The apparatus indicates the presence of a target of interest when the highlight-shadow information is contained in multiple sequential signals over a predetermined range window.