Robust Spoofing Detection for GNSS Array Instrumentation Based on C/N0 Difference Measurements

In recent years, Global Navigation Satellite System (GNSS) spoofing detection techniques have attracted wide attention. Spoofing attacks have posed a greater security threat than jamming and are more difficult to detect due to their strong concealment. One of the key measurements of GNSS instruments is the carrier-to-noise ratio ( $C/N_{0}$ ), which may be affected by spoofing. However, the variations in $C/N_{0}$ are always uncertainty especially for the array instruments under the attack. This article proposes a method for GNSS array instruments to detect the spoofing after anti-jamming. A theoretically model of the effective $C/N_{0}$ in array receiver is deduced. The $C/N_{0}$ single difference (CSD) between satellites is further proposed as a testing statistic for spoofing detection. Simulation results demonstrate that the proposed method can effectively detect the abnormal $C/N_{0}$ feature of counterfeit signals after anti-jamming by the antenna array. The detection performance of the proposed metrics is verified in the jamming and spoofing scenarios using the real data collected by an antenna array instrument. This method does not require modifications to the hardware configuration of conventional array receivers and can provide an effective defense in the combination of jamming and spoofing attacks.