Patent ID: 6366734
Filing Date: 2002-04-02
Classification: G01C

Abstract:
In aerial reconnaissance photography, a method of compensating for forward motion of a reconnaissance aircraft while generating a frame of imagery of a scene of interest by a camera installed in said aircraft, said camera comprising (a) an Cassegrain optical system having a primary mirror, a secondary mirror fixedly mounted relative to said primary mirror, and a flat azimuth mirror positioned in the optical path between said primary mirror and said secondary mirror, and (b) at least one framing image recording medium, said Cassegrain optical system and framing image recording medium incorporated into a camera housing mounted to the vehicle, said camera housing defining an axis; comprising the steps of:(1) orienting said camera housing such that said camera housing is substantially parallel to the roll axis of said aircraft; (2) rotating said primary mirror and secondary mirror at a rate about an axis orthogonal to said roll axis in the direction of flight of said aircraft, while maintaining said image recording medium in a fixed condition relative to said camera housing; and (3) while rotating said primary mirror and secondary mirror as recited in step (2), rotating said azimuth mirror in the direction of flight at a rate one half the rate of said rotation of said primary mirror and said secondary mirror in step (2).