New study shows: GNSS-disturbances in the southern Baltic Sea are significantly more complex and stronger than previously assumed
A new investigation builds on our earlier report on GNSS-interferences in the Baltic Sea region (with GPSPatron and the Gdynia Maritime University) — but this time with a crucial difference: instead of a fixed sensor on land, the interference detector GP-Probe TGE2 was installed directly aboard a research vessel. The ship operated between 23 June and 14 October 2025 throughout the southern Baltic Sea region and regularly approached the maritime border region to Kaliningrad.
By using this mobile measurement platform, the actual GNSS environment encountered by vessels could be captured — including effects that are not visible from land.
Key findings
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Shift to combined spoofing and jamming attacks
While the earlier coastal study exclusively showed multi-constellation jamming, the new shipborne campaign reveals a different picture:-
GPS-L1 spoofing with artificial satellite signals.
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Simultaneous jamming of GLONASS, Galileo and BeiDou.
This forces receivers to use only the fake GPS signals — a technically efficient, yet highly effective interference with navigation.
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Highest disturbance intensity measured so far
At the end of June to July the strongest disturbances occurred:-
GNSS availability dropped to 83.5 %.
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Over 4 days of spoofing were registered.
The most extreme incident: almost 30 hours of continuous spoofing from 1 to 3 July — a serious risk for shipping.
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Multiple jamming transmitters working synchronously
The data clearly shows: the interferences originate from four different, coordinated sources — including a GPS-spoofer, two chirp-jammers and a broadband analog jammer.
Different spectra and bandwidths point to spatially separate installations, yet centrally controlled activation. -
Significant change in technology
Compared to the earlier study:-
fewer but more powerful chirp-jammers.
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a combination of older high-power RF technology with newer spoofing capability.
The interference landscape is thus becoming technically more heterogeneous and unpredictable.
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Disturbances increase significantly at sea
Measurements show a clear spatial trend:-
In the port of Gdańsk: weak.
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On the open sea: up to 15 dB stronger.
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Strongest values were observed when heading toward Kaliningrad.
This means that navigation zones at sea are particularly affected by the disturbances.
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Request the full report
The complete report with spectrograms, signal analyses and technical details is available for download. To download: simply fill out the email form.
If you have any questions or need further information on this topic, we are happy to assist via email.
