US Patent 7031727 Method of location using signals of unknown origin

The present invention encompasses a method of location comprising: using a plurality of signal receivers to receive one or more multiple frequency input signals, wherein said multiple frequency input signals are of unknown origin, and said signal receivers are of known physical location, finding a difference in time of the reception of the signals between each of the signal receivers, using the difference in time of reception to locate the origin of the signals, utilizing the signals locate a signal receiver of unknown location.