GNSS Spoofing Detection Method Based on the Pseudorange Difference Between Epochs for Single-Antenna Receivers

Spoofing attacks against the Global Navigation Satellite System (GNSS) are difficult to perceive and highly destructive, and they therefore constitute a serious security threat to GNSS services. Although numerous countermeasures have been reported, those exploiting the direction of the incoming signal generally rely on antenna arrays, on several cooperating receivers, or on a single antenna kept in motion, all of which raise the hardware cost and the implementation complexity. Motivated by this limitation, this article develops a spoofing detection scheme for single-antenna receivers that operates on the pseudorange difference between epochs. The key idea is that this epoch-wise difference can be predicted with high fidelity from ephemeris data and successive positioning solutions, so that under authentic conditions the measured and the predicted differences agree in a statistical sense. Once spoofing is present, the geometric and kinematic mismatch between the true satellite and the spoofer, together with the pull-off manoeuvre of the counterfeit signal, destroys that agreement and thereby exposes the attack. Because no assumption is imposed on the number of transmitting sources, the scheme is in principle able to reveal spoofing radiated from several directions at once. Monte Carlo trials are carried out to quantify how the individual design parameters govern detection capability, and the scheme is then verified on a public dataset as well as on a dataset collected by the authors. The outcome confirms that spoofing arriving from different directions is reliably identified with one antenna only, which relaxes the antenna requirement imposed by direction-based methods for multi-agent spoofing; detection is further shown to be more favourable when the receiver is moving or when the spoofer pulls off at a high rate. The detector is most responsive while the counterfeit observables are being pulled away from the authentic ones, and the margin it retains once the attack has settled into a steady state depends on how faithfully the attacker tracks the motion of the target, so that an absolute or geometry-based integrity monitor is the natural complement wherever that margin becomes narrow.