The Norwegian fishing town that’s trying to help solve GPS jamming

In March 2023, two airline groups issued warnings to pilots about GPS jamming over the South China Sea, the Philippine Sea and eastern Indian Ocean. Similarly, Russia has been blamed in recent years for interference near Poland, Scandinavia and the Baltic States. And with wars in Ukraine and the Middle East, jamming navigation satellites around those borders has become an inconvenient and potentially dangerous part of everyday life.

But in September, government and industry officials arrived in the small fishing town of Bleik, Norway for an event known as Jammertest 2024, thought to be the world’s largest open jamming exercise. There, officials tested their products and systems against accidental and intentional attacks that aim to block or wreak havoc on position, navigation and timing signals.

Because of the area’s unique geography, surrounded by mountains on three sides and just one road in and out, the Norwegian government can isolate the test area from the mainland. Residents are warned weeks ahead of time to expect unstable GPS results and possibly incorrect GPS positions and time.

“During the last few years, after we started experiencing Russian interference or jamming on our border up in the north in Norway, the issue has been taken more seriously than in a lot of other countries.” said Nicolai Gerrard, a senior engineer at the Norwegian Communications Authority who helps organize the event and focuses specifically on interference for such systems. “You went from a situation where this existed, and also, probably more than people realized, to something that was there all the time.”

At Jammertest, cars, drones, planes, helicopters and ships faced interference. While some of this testing can be done in laboratories, it is no substitute for such exercises.

The U.S. Space Force flies more than 24 Global Positioning Satellites for position, navigation and timing in medium Earth orbit. Government officials have described the service as an essential part of information infrastructure from cell phones to ATMs and a key part of banking systems and power grids for its precise time synchronization. Several other nations fly their own global navigation satellite systems with more than 100 of those satellites on orbit.

But because of their immense and universal value, the GPS signals themselves become attractive targets.

“Jamming and spoofing efforts can put at risk public safety, causing collateral damage and impacting civilian and commercial activities in the vicinity of conflict zones,” experts from the Center for Strategic and International Studies wrote in April 2024 as part of their annual space threat assessment. “The activities violate international spectrum rules, as the UN International Telecommunications Union specifically prohibits any transmission of false or misleading signals.”

Military officials have complained for years about low power jammers that are inexpensive and available online. Participants at Jammertest wanted to see how their tools could work against both low-end, sometimes derisively known as “Ebay jammers” and high-end attacks.

This year, attendees also faced what organizers expect to be part of the next frontier of such sabotage. That included spoofing from both moving and stationary devices and exposing systems to interference over longer periods of time. They also dealt with meaconing, which is the interception and rebroadcast of navigation signals at a higher power to create confusion and give inaccurate bearings. And they experimented with boot loops in which one misplaced parameter can cause a device to restart over and over until it is eventually out of commission.

The wide range of interference is not going away. It’s also why solutions are needed.

Among the possible answers: Gerrard said more teams this year tested with Controlled Reception Pattern Antennas, or CRPA antennas, that create a filter that eliminates signals from a particular direction, likely where the interference is coming from, while allowing in legitimate signals from other directions.