October 2025: A strong, repetitive radio signal has been interfering with GNSS signals across Europe as far back as 2019.
The BBC’s Science in Action was interested in learning more. “This is the main finding of my student Zach Clements’s work,” the RNL’s Dr. Todd Humphreys responded, “where he’s determined with a high degree of certainty that the interference we’ve noticed… is coming from space.” Zach Clements, a PhD student in Aerospace Engineering at the University of Texas at Austin and RNL researcher, presented his findings at the 2025 ION GNSS+ conference.
Many continuously-operating GNSS reference stations, scattered across the hemisphere, have been reporting simultaneous bursts of interference. Primarily striking the Baltic states, Finland, and Norway — with Svalbard, Spain, Canada, and Greenland marginally affected — the interference cannot be coming from the surface.
The interference is likely triggered by human activity. But “if this is deliberate, it’s a strange kind of deliberate.” Dr. Humphreys stated that, “what we see is fairly constant in the kinds of temporal patterns and spatial patterns,” with an estimated signal power reaching as high as 2kW from a satellite in GEO. It is possible that this interference source is coming from routine satellite maintenance, unbeknownst to the satellite operator.
“By putting the pattern together, the timing, and… the spatial distribution, we’re able to reduce the number of candidate satellites just to those you could count on one hand,” said Dr. Humphreys. These findings develop new tools to identify sources of jamming, defending against the future of electronic warfare.
Listen in with the BBC’s Roland Pease here.
