GPS systems across the Baltic Sea region, including Estonia, reported disturbances at the end of last year, monitoring websites show. Russia is to blame, the Consumer Protection and Technical Regulatory Authority (TTJA) said.
Between Christmas and New Year's Eve, tracking website gpsjam.org detected GPS jamming across the Baltic Sea. Countries affected included Finland, Estonia, Latvia, Poland, Sweden, and Russia
Estonia was most severely affected on December 31. Images from gpsjam show there were major disturbances along the eastern border and in the south. Latvia and eastern Finland also saw heavy jamming.
As of Tuesday (January 2), in Estonia, the issues remain in Põlva and Räpina but have cleared across the rest of the country.
Estonian authorities have said little about the incident except that the jamming has had no significant impact. The Air Force and Navy have been working as normal with no interference, the General Staff of the Defense Forces told ERR.
The Ministry of Defense said it does not publically share assessments of such incidents.
The Estonian Air Navigation Services, which controls Estonia's air traffic, told ERR, that since GPS is only one type of navigation system in use, it has not felt any disturbances.
"In aviation, there are always several navigation systems in use at the same time, supporting and complementing each other. This means that even if the GPS signal is disrupted, the information needed for air traffic is available," said spokesperson Lotte-Triin Narusk.
To further reduce future risks, the agency is implementing new ground distance meters. These devices are scattered across Estonia and can determine the locations of aircraft, said Narusk.
TTJA: Disturbances come from Russia
Frequency monitoring is the responsibility of the TTJA in Estonia.
Head of the agency's frequency management service Erko Kulu told ERR it has noticed a slight increase in GPS interference in Estonia since last June.
"However, we can say that there are no significant problems with the operation of the GPS devices and that they can be used as usual," he said.
Kulu added that interference with the GPS signal does not affect business and passenger aviation and poses no threat to them. GPS, Galileo and other global satellite navigation devices used on the ground have not been affected.
Kulu said the disturbances come from Russia.
"The source of the interference is estimated to be in Russia's Leningrad Oblast region, with a small potential spillover into Estonian and neighboring airspace," he said.
Poles warned pilots
On December 25 and 26 major GPS disturbances were reported in the southern part of the Baltic Sea.
Polish media reported that "mysterious and massive" GPS signal disturbances extended from southern Sweden across the Baltic Sea to Poland and Lithuanua. Most of the other countries around the Baltic Sea were not affected.
The Polish Air Service also issued a warning to airlines over Christmas. The Poles could not say anything concrete about the cause, while local experts suggested it may have been the weather.
Gpsjam.org owner John Wiseman said this is the biggest disturbance in the region since the website was founded two years ago.
"At first I thought this massive GPS jamming might be a NATO/Polish exercise, but now I'm leaning toward it being Russia. Not just because the answer to "Who's jamming GPS?" is usually Russia, but yes that's part of it," he wrote on the social media website X.
Both Wiseman and the Finnish airline Finnair have said that these disturbances do not pose a threat to air traffic.
A security specialist from the Helsinki-based European Centre of Excellence for Countering Hybrid Threats told the Finnish broadcaster Yle that the incident is likely to be a Russian hybrid attack.
So much GNSS/GPS interference is unprecedented over this part of the Baltic, at least since I started collecting data 22 months ago. The first hint of it appeared Dec. 13, but the number of flights affected (the yellow bars) in the past 24 hours dwarfs any other day–nearly 40%. pic.twitter.com/4JYtU3t5EJ— John Wiseman (@lemonodor) December 27, 2023
Editor: Helen Wright