Detection and Mitigation of GPS Spoofing Based on Antenna Array Processing

In this article authors present an application of spatial processing methods for GPS spoofing detection and mitigation. In the first part of this article, a spoofing detection method, based on phase delay measurements, is proposed. Accuracy and precision of phase delay estimation is assessed for various qualities of received signal. Spoofing detection thresholds are determined. Efficiency of this method is evaluated in terms of probability of false alarm and probability of detection when 4 to 8 GPS signals are received. It is shown that the probability of spoofing detection is greater than 99 percent if carrier-to-noise ratio is at least 46 dBHz. The second part of the article presents a GPS spoofing mitigation method which uses spatial filtering (null-steering) for excision of undesired signals. Performance of this method is analyzed in various conditions. Attenuation of undesired signals is estimated to be at least 60 dB when their signal-tonoise ratio is high. Furthermore, statistical analysis of the spatial filtering influence on the availability of true signals is provided. Eventually, a concept of practical anti-spoofing system implementation is proposed.