Abstract: Four pulse-repetition-frequency coded laser diode arrays emit four beams in quadrature relationship having a central optical axis coinciding with the missile axis. The returned reflected energy from a target impinges upon an optically centered holographic quadrant selector detection system which provides quadrature output signals. These quadrature output signals are passed through respective pulse-repetition-frequency discriminators corresponding to the quadrature prf coded transmitted beams. The outputs from the discriminators are processed through a null comparison circuit to provide output signals for actuating the servo guidance system of the missile to center the optical axis, which is also the missile axis, on the target so that the missile continuously seeks and eventually flies into the target.