Range gated retroreflective missile guidance system

Abstract

An optical tracking link in an automatic command to line-of-sight missile idance system improves the system efficiency and employs a reuseable light source. In tracking a missile during trajectory toward a target, short pulses of collimated light are transmitted from the launch site toward the missle. These light pulses are received by a missile optical receiver for guidance of the missile and are simultaneously reflected by a retrodirective prism on the missile. The reflected energy follows a path parallel to the incident wave and is thus directed back to the launch site. A missile tracker at the launch site responds to the reflective energy, measuring any deviation of the missile from a line-of-sight axis maintained between the launch site and a target. Guidance commands are transmitted toward the missile for maintaining the missile on the line-of-sight trajectory and containing correctional signals in response to any missile deviation. During intervals between return reflections, the missile tracker can be gated off. This greatly reduces background and jamming source reflections and signals, received by the tracker providing effective counter measures hardening of the system.