Patent ID: 8179310

Claim:
A method for sensing a potential threat to an object from an entity that passes through a direct sight line between navigation satellite transmitters which form a satellite transmitter group, and a plurality of receiving stations, said entity causing irregularities to be added to expected signals transmitted from said navigation satellite transmitters, the method comprising: receiving signals from said navigation satellite transmitters at each receiving station, each receiving station being remotely located from each other and located in a different receiving platform; detecting, at each receiving station, irregularities relating to the received signals on a basis of a difference between an expected received signal and the received signal; transmitting, in response to a detection of irregularities, by each receiving station that detected an irregularity, said received signals at each receiving station to at least one evaluation center, each of said at least one evaluation centers being regionally located; evaluating, collectively, the signals received from each receiving station that transmitted the received signals; and sensing a potential threat based upon said evaluating.