GPS signals can be jammed using a simple low-power transmitter, so the Pentagon and Britain’s Ministry of Defence have developed a method of pinpointing the rogue broadcaster’s location using spy satellites – wherever they may be at the time.
Part of the system relies on existing triangulation techniques. Two US spy satellites detect the rogue signal and relay it to a monitoring station in Britain. The signals arrive at slightly different times and that difference is a measure of the transmitter’s relative distance from each satellite, and hence its position on the ground. But the MoD’s patent (US 2002/0070889) describes how…
