AIS-Based Maritime GNSS RFI Monitoring With Multi-Vessel Coherence and Communication-Integrity Artifact Mitigation
Global Navigation Satellite System (GNSS) radio-frequency interference (RFI), including spoofing and jamming, threatens maritime positioning, navigation, and timing. Automatic Identification System (AIS) reports provide GNSS-derived vessel positions, offering an opportunistic wide-area monitoring source; however, raw AIS streams contain communication-integrity artifacts, such as duplicated ship identifiers and stale-data retransmissions, that can mimic trajectory distortion or reporting outages, and isolated single-vessel anomalies cannot be unambiguously attributed to GNSS interference. This paper proposes an AIS-based framework that mitigates communication-integrity artifacts, generates kinematic-consistency and transmission-continuity anomaly cues, and groups retained cues into multi-vessel events using spatiotemporal Density-Based Spatial Clustering of Applications with Noise (ST-DBSCAN). Applied to approximately 966 million AIS messages from Korean coastal waters, the framework retained 48 spoofing-consistent distortion events and 98 jamming-consistent reporting-outage events. These results suggest that AIS can serve as a complementary source for maritime GNSS RFI monitoring.