1. A system for tracking a target comprising: a directional sensing means for sensing an image of at least a portion of the target, said sensing means having outputs which are video signals in accordance to the image sensed, a video processor having inputs connected to outputs of said sensing means, said processor including means for clamping to ground the video signal at a predetermined position of a contrast area on the image, circuit means connected to outputs of said processor so as to generate at its outputs, tracking gates about said contrast area, tracking means connected to the outputs of said circuit means and said processor so as to track a center position of said contrast area and provide orthogonal error signals of the position of said contrast area, and servoing means connected to said orthogonal error signals and to said directional sensing means for positioning the sensing means so that the image sensed will include said contrast area.