Steering mechanism for a thermal imaging system and rangefinder therefor

Abstract

A steering mechanism is described for use in conjunction with a thermal imaging system. The steering mechanism comprises a pair of prisms which are positioned serially in front of the scanning mechanism of the thermal imaging system. The prisms are individually rotated by a motor means. A position encoder is connected to each of the prisms to provide feedback position information to a search computer which controls the rotation of the prisms. The refraction of the thermal image produced by the rotating prisms enables the scanning mechanism of the thermal imaging system to search in any searching pattern within a variable field of regard in the field of search of the steering mechanism. The steering mechanism may also function to boresight a laser on the same target viewed by the thermal imaging system. In one embodiment, the laser comprises a pulsed-type laser whose pulsed laser beam is transmitted through the prisms onto an acquired target. The reflection of the pulsed laser beam is then reflected from the acquired target and detected by the thermal imaging system. The lapse of time between transmission and detection of the pulsed laser beam enables the computer to compute the range of the target. The laser may alternatively comprise a low power continuous output laser which may function as a laser designator for beam rider devices.

Dependencies are inferred from the claim text.