System and method for determining the bearing of a source location from a receiver location

Abstract

The system comprises a first beatable signal source, a second beatable signal source, a phase reference signal source and a receiver. The first beatable signal source and the second beatable signal source are located at the source location; the receiver is located at the receiver location. The phase reference signal source is operable to generate a phase reference signal. The first beatable signal source is operable to transmit a first beatable signal. The second beatable signal source is spatially offset from the first beatable signal source in a reference direction, and is operable to transmit a second beatable signal differing in frequency from the first beatable signal by a frequency difference. The first beatable signal and the second beatable signal collectively have a phase relationship with the phase reference signal. The receiver is structured to receive the first beatable signal and the second beatable signal and is operable to determine a direction angle, relative to the reference direction, of the source location from the receiver location. The receiver performs operations that comprise measuring a phase difference between a beat signal and either the phase reference signal or an additional beat signal, and determining the direction angle from the measured phase difference. The beat signal obtained by a process involving summing the first beatable signal and the second beatable signal. The additional beat signal is obtained by a process involving summing the first beatable signal and the phase reference signal. The bearing can be determined from the direction angle.