Design and capabilities
GPS spoofing deceives a satellite-navigation receiver by broadcasting counterfeit signals structured to resemble genuine GPS or GNSS transmissions, or by rebroadcasting real signals captured elsewhere or at an earlier time, so the receiver computes a false position, velocity, or time. It differs from jamming, which simply blocks reception: a spoofed receiver still reports a plausible-looking fix, just an incorrect one, which makes the deception harder to catch in real time. More sophisticated "circular spoofing" generates a smoothly moving false position rather than a static jump, specifically to defeat basic plausibility checks built into some navigation software.
Operational history
Finland's Coast Guard in the Gulf of Finland has documented persistent GNSS interference since 2024, including deliberate spoofing of tanker positions concentrated around vessels calling at Russian ports near St. Petersburg. Commander Pekka Niittylä told Reuters in October 2024 that spoofing had been detected roughly ten times by different tankers, alongside cases of automatic identification system devices being switched off so a vessel's displayed location no longer matched its actual position. Maritime intelligence firm Windward reported in 2025 that GPS jamming was diverting the AIS-reported positions of tankers calling at the Russian ports of Ust-Luga and Primorsk into a ring-shaped pattern of false coordinates off the Finnish coast, with a second cluster of false positions appearing near Kaliningrad; Windward recorded roughly 460 vessels affected in the Baltic Sea over one thirty-day monitoring period.
AirVeto context
Spoofing is one half of the navigation-warfare toolkit affecting the stretch of the Baltic Sea that AirVeto covers, alongside the loss-of-signal jamming covered in the neighbouring glossary entry. Finnish authorities assess the pattern as intended primarily to mask tanker movements at Russia's own Baltic oil ports from Ukrainian strikes, rather than as a direct attempt to disrupt neighbouring states' shipping, though the effect on navigation safety in surrounding waters is the same either way. Persistent AIS spoofing is now a routine, near-daily feature of monitoring in the Gulf of Finland and southern Baltic; readers tracking drift incidents alongside electronic interference should treat a vessel's displayed position with caution in this stretch of water.