Velocity Consistency Checking Based GNSS Spoofing Detection Method for Vehicles

Autonomous driving, unmanned aerial vehicles (UAVs), and various other vehicular navigation schemes heavily depend on the accurate position, velocity, and timing (PVT) information offered by global navigation satellite systems (GNSSs). Meanwhile, GNSS security is challenged by spoofing attacks that aim to deceive users by inducing false PVT solutions. Therefore, detecting these attacks on time is vital for vehicular navigation security. Spoofing attacks involve transmitting counterfeit signals from spoofers instead of authentic satellites, making it difficult to coordinate spatial information accurately. To this end, the Doppler shift, revealing spatial features between transmitters and receivers, is regarded as an effective metric for spoofing detection. Especially for vehicles, due to their motion relative to the spoofer, Doppler bias is appended to the raw measurement, providing an observable spoofing signature. Conventional approaches tend to directly monitor the Doppler bias but require complex requirements like static initialization, random motion, and multiple receivers. Moreover, the commonly utilized single-antenna assumption renders them ineffective against multi-antenna spoofing attacks. This paper proposes a new approach that indirectly exploits the Doppler bias by examining its adverse impact on velocity consistency. The introduced direct velocity determination (DVD) method calculates velocity directly from the Doppler measurements, which is then utilized for consistency-checking alongside the velocity obtained from the conventional pseudorange-aided approach. We thoroughly investigate the impact of Doppler bias on velocities and analyze their consistency across different scenarios. Field tests validate the effectiveness of the proposed method, surpassing previous Doppler-based methods and the widely used receiver autonomous integrity monitoring (RAIM) method.