A monopulse type receiver utilizing pilot carrier techniques for providing precise angular error information. Four detector cells are arranged in a quadrant configuration for detecting pulses of laser energy, with the output from each cell being delivered to a respective video channel. Each video channel comprises amplification circuitry including an inner loop automatic gain control (AGC) which operates both on noise and the pilot carrier signal to ensure uniformity of response for each video channel. The video channel outputs are fed into respective sample and hold circuits which provide voltage amplitude outputs both to an outer AGC loop and to a pair of command signal normalizer circuits. The outer AGC loop raises or lowers the gain of each of the video channels as required by controlling the amount of pilot carrier signals interjected into the front of the system. The outputs of the normalizer circuits represent ratios of the energy difference in the four channels divided by the sum of the energies of the channels to provide the desired angular information to a gyro head or the like. Pulse presence determination circuits are also provided in order to reject pulses wider than would be expected.
MONOPULSE GAIN BALANCED AMPLIFICATION SYSTEM USING PILOT CARRIER TECHNIQUES