GNSS Spoofing Detection Based on Ionospheric Model Deviation Monitoring

Spoofing attacks on global navigation satellite system (GNSS) are posing significant safety risks to receivers. However, the widely used dual‐frequency (DF) receivers offer a new antispoofing inspiration against DF spoofing attacks. DF receivers can estimate ionospheric total electron content (TEC) using both the DF TEC measurement model and the empirical model. Because of the different accuracy of these two models, the deviation of TEC (DTEC) consistency between DF measurements and empirical model estimations in authentic scenarios is not zero but is predictable through ionospheric annual periodicity. However, DF spoofers typically struggle to accurately counterfeit the authentic TEC value, which can disrupt the consistency between DTEC measurements and predictions. Based on this gap, we propose a spoofing detection and recognition method named TEC model deviation monitoring (TEC‐MDM) method by checking DTEC consistency between measurements and predictions. In spoofing scenarios, on one hand, simulator‐based spoofers typically use empirical models to simulate ionospheric states, which is not accurate enough to maintain DTEC consistency. On the other hand, even if spoofers can simulate ionospheric states accurately, receivers may have prior authentic position information or use both authentic and spoofing signals for positioning because the spoofing signals are typically power‐limited for covertness and hard to suppress authentic signals, which causes position estimations to deviate from false positions preset by the spoofer and disrupt the DTEC consistency due to ionospheric spatial variation. Simulation experiments are conducted to theoretically and numerically analyse the influencing factors of the proposed TEC‐MDM method. Field experiments verify that the TEC‐MDM method can effectively detect DF spoofing signals in full‐channel spoofing scenarios (FSS) and recognise spoofing signals in partial‐channel spoofing scenarios (PSS). Furthermore, if the receiver has prior authentic position information, spoofing recognition can also be achieved in FSS.