Detection of GPS spoofing through signal multipath signature analysis
Hao Li, Xianbin Wang · 2016
Spoofing that emulates authentic signals to coerce target receivers into false navigation solutions is a severe threat to many applications based on Global Positioning System (GPS). In order to forge a reasonable navigation solution, a spoofer generally has to mimic signals of several GPS satellites simultaneously. In view of the fact that GPS signals originated from a single transmitter would essentially experience an identical wireless channel to a receiver, a GPS spoofing detection scheme is proposed based on comparing the multipath signature of received signals. More specifically, the delay and gain ratio between multiple paths of a wireless channel that cannot be masked by spoofing signals are exploited. The delays between the strongest and other correlation peaks associated with each satellite are first evaluated. A correlation peak with the same delay for different satellites and closest to the strongest peak is then selected and its ratio to the strongest peak is calculated. With an identical wireless channel, the ratios corresponding to different satellites would be highly correlated. In contrast, ratios of authentic satellite signals that experience independent channels would be independent of each other. GPS spoofing can therefore be detected. The proposed design has been validated by simulations.