Munition actuation signals are generated by an acoustic target ranging system that predicts the time and distance of closest approach of a moving target to a munition. The predictive capability of the system is based on the rate of change of the sound level emanating from the target compared to its absolute magnitude. The system generates munition standby, arm and fire signals by differencing the received acoustic amplitude function signal and its first derivative and subsequently comparing the difference signal with various reference level signals. The reference level signals are a function of munition effective range and target conditions. Mechanization of the system is realized by simple circuitry consisting of an acoustic signal detector and processor, a differentiating operational amplifier, a programmable gain amplifier, a reference level signal source, an adder and a comparator circuit.
Thomas E. Owen; Sidney A. Suhler; Wendell R. Peters