PASSIVE RANGE FINDING APPARATUS UTILIZING TELEVISION SENSORS

The range to an object is obtained by conveying light rays from the object through an afocal telescope to spatially displaced objective lenses that view the scene from two displaced points of view. The scene images from the objective lenses are focussed on two television sensors, respectively. The video frame from the TV sensors are digitized and stored in respective frame grabbers. A timing and logic circuit controls the television sensors and frame grabbers to alternately provide frames from the two television sensors to a monitor. The timing and logic circuit time shifts the output of one of the frame grabbers with respect to the output of the other frame grabber. A correlator responsive to the frame grabber outputs provides the correlation therebetween. The time shift required to bring the video images of the object into coincidence, at the correlation peak, provides a measure of the range to the object.