US Patent 11619700 Retrospective interferometry direction finding

Using captured and stored wideband historical radio frequency data bearing information to the source of a signal of interest achieved using as few as two receivers and a plurality of commutating antennas. Wideband IQ data streams are received at two or more receivers and stored for later analysis. A first receiver is coupled to a reference antenna and a second receiver is commutatively coupled to a plurality of commutating antennas. Later, streams of wideband IQ data are retrieved for a select period of time and synchronized. From these streams a signal of interest identified and synchronously sampled over an acquisition interval by each receiver. Phase differences of the signal at each of the plurality commutating antennas is measured enabling a determination of the bearing to the common signal of interest.