Non-Adjustable Pointer-Tracker Gimbal Used For Directed Infrared Countermeasures Systems

摘要

In a directed infrared countermeasure system, to assure parallelism between the line-of-sight to a target and the output beam, the input and output mirrors are fixedly attached to a uni-construction arm mounted to a rotatable azimuth platter to which internal mirrors are also fixedly attached. A system is provided for zeroing out alignment errors by developing an aim-point map for the gimbal that records initial alignment errors induced by manufacturing tolerances and uses the aim-point map error values to correct the output mirror orientation. The system also corrects for alignment errors induced by thermal gradients.

主权项

1. A system for adjusting the aim-point of a two axis gimbal that employs a uni-construction elevation arm carrying input and output mirrors fixedly attached thereto, the elevation arm mounted on an azimuth platter that carries internal mirrors, comprising:
a two axis gimbal including an azimuth platter and a uni-construction elevation arm; input and output mirrors fixedly attached to said uni-construction elevation arm; internal mirrors fixedly attached to said azimuth platter; a retro-return prism mounted to said azimuth platter; a laser having an output beam; optical path determining elements for directing said laser beam through said gimbal to said internal mirrors, to said output mirror, to said retro-return prism, through said retro-return prism to said input mirror and from said input mirror to said internal mirrors and down to a focal plane array; said elevation arm carrying said input and output mirrors driven to a position such that said output mirror directs said laser beam to said retro-return prism and such that beam from said prism is reflected by said input mirror to said internal mirror and then to said focal plane array; means using said optical path detecting elements for establishing an original calibrated boresight laser beam image on said focal plane array; a unit for firing said laser through said optical path determining elements when said uni-construction arm is in the same position as used for establishing said original calibrated boresight laser beam image and for ascertaining the offset on said focal plane array of the laser beam image on said focal plane array from said originally calibrated boresight laser beam image to establish a boresight offset; an aim-point map; and, means for coupling said boresight offset to said aim-point map for driving the elevation and azimuth stages of said gimbal to an aim-point taking into account said boresight offset such that said gimbal is realigned using said boresight offset.