Signal Quality Monitoring Spoofing Identification Methods for GNSS Vector Tracking Structure

Spoofing interference is an emerging threat to Global Navigation Satellite System (GNSS) receivers. Recent studies have shown that for GNSS receivers with vector tracking structure, both the overlap of correlation peaks and the inconsistency of received signals caused by spoofing interference can affect the coherent integration results. Therefore, signal quality monitoring (SQM) technology has a broader application range for spoofing detection in the vector tracking structure. However, since the inconsistency of received signals can influence all signal channels, the commonly used SQM methods cannot be used for spoofing identification. This article proposes the corresponding SQM spoofing identification methods for two spoofing scenarios with and without overlapping correlation peaks. Specifically, for a signal channel in the first spoofing scenario, the influence degree of the inconsistency of received signals on the coherent integration results of the early (E), prompt (P), and late (E) correlators is the same. By contrast, the overlap of correlation peaks does not satisfy this relationship. According to this difference, the corresponding method can identify the overlap of correlation peaks in the signal channel. For the second spoofing scenario, the corresponding method uses the pseudo-code phase differences estimated from the coherent integration results to distinguish the spoofing signals from the authentic signals. Furthermore, a series of simulations are conducted to prove the feasibility of the proposed two spoofing identification methods.