Fiber optic guidance system for laser guided missiles

Abstract

The invention provides a system and a method for determining the direction to a radiating source, for use by a vehicle guidance system, in which optical fibers are used to both collect and transmit optical signals in which the vehicle is preferably intended to home in on its target. The optical fibers disclosed herein require no separate collection optics, but instead directly collect incident radiation arriving at one end of the optical fiber for transmission to a photodiode detector coupled to the distal end. Preferably the radiation is laser radiation radiating from a target in relation to which the vehicle is guided, and preferably the vehicle is a guided missile. Elimination of collection optics reduces the complexity and cost of the apparatus and provides an unexpected increase in and selectability of the accuracy of directional determination by the system. The system includes an array of apertures disposed in selected, non-uniform locations on the vehicle. Each aperture contains a set of fibers, including start and stop fibers. The fibers receive incoming radiation, transmit the radiation as optical signals to start and stop detectors. The detectors measure a signal strength and a property related to the length of the start and stop fibers through which the optical signals have been transmitted, and provide output indicative of the signal strength and the property to a microprocessor. The microprocessor is programmed to calculate the direction to the radiation source relative to the vehicle, and to provide this information to a vehicle guidance and control system.