Polish study suggests ships are conducting GPS jamming operations in the Baltic

A study by Polish researchers claims that moving vessels on the Baltic Sea are responsible for an escalation in GPS disruptions in the region.

The study observed GPS interruption at a ground level with a sensor installed at Gdynia Maritime University in the north of Poland, some 120 km from the Russian exclave of Kaliningrad. 

The sensor monitored activity over a period of six months starting from June last year but could only cover the Gulf of Gdańsk, not the main east-west sea lanes of the central Baltic, where the vast majority of the region’s traffic occurs. 

The sensor picked up 84 hours of GPS interference, including 29 hours in October alone. 

Some disruptions lasted up to seven hours at a time, which is sometimes enough to affect navigation in confined waterways. 

“Given the system’s radio horizon, which primarily covers a portion of the Baltic Sea, and assuming that the interference source was not located within Poland’s borders, the most plausible explanation is that the jamming originated from a vessel in international waters,” the researchers concluded.

There have been reports earlier of special equipment found on shadow fleet ships, including the Eagle S (pictured), a tanker accused of severing a cable in December last year. 

“To mitigate these risks, there is an urgent need for a dedicated GNSS interference monitoring network along the Baltic Sea coast. Such a network would provide real-time, localized data to accurately assess threats, detect interference sources, and enhance infrastructure resilience against GNSS disruptions,” the authors of the new study compiled by GPSPATRON and Gdynia Maritime University, warning that failure to do so could potentially lead to “severe operational and security consequences”.