Abstract: A guidance system for automatically boresighting a small field-of-view, lresolution image, sensed by an infrared missile imaging sensor, to a large field-of-view, high-resolution image, sensed by an imaging sensor located within an airplane. The image sensed by each sensor is applied to a digital correlator which makes a bit-by-bit digital correlation of the images. The image sensed by the large field-of-view aircraft sensor is monitored on a CRT. Cross-hairs are placed at the centerpoint of the area in the monitored aircraft sensor image which has the highest correlation with the missile sensor image. Thus the boresight of the missile sensor is ostensibly located in the monitored, aircraft, sensor image.This system may be used to slave automatically one sensor boresight to another. Where a plurality of missiles are carried by one plane, the boresight of each missile may be located in the large field-of-view aircraft monitor.