A method of determining the location of an unknown source (10) transmitting an unknown signal to satellite relays (14 and 16) comprises receiving the signal from the relays at respective receivers (18). The receivers (18) receive reference signals via respective relays from a common source (22). The...http://www.google.de/patents/US6018312?utm_source=gb-gplus-sharePatent US6018312 - Locating the source of an unknown signal
