Wideband signal processing for emitter location

The location of a fixed transmitter may be determined by processing the signals collected by two moving receivers. This process involves the simultaneous determination of the difference in propagation delay from the transmitter to the receivers and the rate of change of delay difference induced by the motion of the receivers. This paper describes a system approach to the real time computation of a cross ambiguity function (CAF) for wideband signals, such as frequency hopping radios, that is designed around a wideband optical processor. The optical processor subsystem generates a wideband CAF (delay, delay rate of change coordinates), as opposed to a narrowband CAF (delay, frequency shift coordinates), includes a narrowband interference suppression capability and high dynamic range. A system functional description is presented along with location performance estimates. The optical processor subsystem concept, a compact implementation approach and estimated performance are also discussed.