Abstract: A technique for is presented for locating at least one object illuminated by a laser designator. A detector and an optical unit are provided. The one optical unit is configured for receiving a beam of laser light scattered by the at least one object being illuminated by the laser designator, for creating two secondary beams, and for focusing the two secondary beams to respective foci along an optical axis of the at least one optical unit. The detector is located between the two foci, divided into an even number of portions, and is configured for measuring an intensity of impinging light at each portion. The optical unit is configured for causing the received laser light to impinge the detector, such that an upright image and an inverted image of the scattered laser light beam having substantially equal sizes and substantially equal energies are projected on the detector.

Abstract: A technique is presented for tracking a target illuminated by a laser designator. A light beam scattered from the target in response to illumination by the designator is received and projected on a detector as an unfocused spot. The detector is divided into a plurality of sectors, each sector being adjacent to two sectors and all sectors meeting at a common point. Each sector outputs a signal indicative of a respective energy of the portion of the light beam illuminating the sector of the detector. A sum of the signals is determined. A plurality of ratios is determined, each ratio corresponding to a respective sector and being calculated by dividing a signal from the respective sector by the sum of the signals. The orientation of the system with respect to the target is determined based on the three ratios, via a look-up table and/or via one or more algorithms.

Abstract: Apparatus for controlling the direction of a beam of optical radiation from, say, a laser, includes two prisms of small apex angle independently rotatable about a common axis. A control circuit is responsive to the actual angular positions of the prisms and to inputs indicating the desired beam position to cause the prisms to be moved to the appropriate positions.