Pulse integration is utilized on board an optically guided missile or other
ordinance device used as a part of a target designation system for extending the
lock-on range of the missile by approximately 18%, when a double pulse laser is
utilized to illuminate and designate the target. Pulse integration is accomplished
with a recirculating delay unit which superimposes the first pulse on the second
pulse, such that while the pulses add coherently, noise does not add in phase.
The pulse integration technique therefore enhances the signal-to-noise ratio when
the missile is at the outer limits of its operating range. When the missile is
sufficiently close to the target, doublet decoding is actuated to offer countermeasure
resistance. At this point, pulse integration may proceed in lieu of doublet decoding
or may be dispensed with in view of the increased signal-to-noise ratio due to
the close range of the missile to the target.
