Galileo Signal Authenticity Verification Using Signal Quality Monitoring Methods

Civilian GNSS signals are highly vulnerable to structural interference due to publicly known signal structure and lack of encryption. This type of interference includes counterfeit GNSS like signals that are designed to deceive target GNSS receivers without being detected. A synchronized structural interference signal can mislead the tracking process of a receiver which may lead to the generation of a fake position solution. This paper focuses on analyzing the effect of this category of interference on correlator outputs of a Galileo receiver. Several signal quality monitoring (SQM) metrics are then designed to detect an abnormally shaped or asymmetric Galileo correlation peaks that are distorted due to the interaction between authentic and counterfeit signals. The statistical properties of the proposed metrics are then analyzed and proper interference detection thresholds are calculated based on these properties. Results show the effectiveness of these metrics in various scenarios of overlapped structural interference added to authentic Galileo signals.