Something is jamming GPS over Europe. Here's what we found

In November 2024, Professor Todd Humphreys and his student Zach Clements investigated a tip-off about unusual GPS signal drops. They analyzed data from a network of monitoring stations and found that on 75 days since 2019, signal-to-noise ratios dropped by a factor of 10 simultaneously across Europe, from Svalbard to Spain and as far west as Canada. The pattern suggested a blast center near Poland or Kaliningrad, but the scale was continental, not local.

The researchers ruled out ground-based interference because even the highest tower in Kaliningrad could only affect aviation as far as Denmark. The curvature of the Earth would block signals over such distances. Using conservative geometry, they calculated the source must be at least 1,200 kilometers up—higher than the International Space Station—leading to the conclusion that only a satellite could cause such widespread, simultaneous disruptions.

Solar interference typically builds and fades over tens to hundreds of seconds, but these events were abrupt bursts lasting only three to five seconds. Solar bursts also span a wide range of radio frequencies, whereas this interference was confined to a narrow 5 MHz slice centered at 1,577.5 MHz—right in the GPS band. Additionally, solar events affect the entire sunlit side of Earth, but these disruptions were consistently centered over Europe.

GPS receivers determine location by listening to signals from satellites that contain the satellite's position and the exact time the signal was sent. The receiver calculates the time difference, multiplies it by the speed of light, and gets the distance. With one satellite, the receiver is somewhere on a sphere around it; adding a second satellite narrows the position to the intersection of two spheres, enabling precise location.

Researchers set up an estimation problem to identify the jammer. By requiring that a satellite be above the horizon for all affected stations simultaneously, they eliminated over 98% of the 15,000 active satellites, leaving about 200 possibilities. Further filtering by multiple events reduced the list to just 14 suspects, many in or near the geostationary belt at 36,000 km altitude.

One candidate was an Algerian satellite with a transmitter in the interference band. However, it was barely above the horizon for distant stations in Svalbard and Greenland, and its signal-to-noise ratio dropped in the same proportion as other GPS signals during events. This indicated it was also being jammed, not the source, forcing researchers back to the drawing board.

The team had assumed a single satellite caused all events, but this was controversial. Breaking that assumption opened up many more satellites beyond the 13 remaining, potentially 100 or more. This felt like starting over, prompting a need for a completely different approach using raw radio signals with higher temporal resolution.

Existing GNSS receivers output simplified measurements once per second, but interference bursts lasted only 3–5 seconds, providing too few samples to compare timing across receivers. To pinpoint the source, researchers began designing specialized receivers to capture raw radio signals at much higher temporal resolution, planning to deploy them across Europe.

The video argues that the threat to GPS is not new; severe solar events can ionize the atmosphere and block satellite signals, or destroy satellites outright. The Kessler effect in medium Earth orbit could also destroy satellites with debris. These existing vulnerabilities mean society should already have been concerned about GPS reliability, and the jamming issue is just another example of why.

The proposed fix is a resilient national PNT (Positioning, Navigation, and Timing) architecture that combines signals from space, terrestrial broadcast, and fiber optics. These three different phenomenologies ensure that if one vector is impacted, the other two remain unaffected. This approach reduces reliance on weak satellite signals and provides redundancy.

South Korea, China, and the UK are already implementing backup networks that do not depend on satellite signals. They use fiber optic cables to securely share time from atomic clocks on Earth, and for navigation they turn to systems like eLoran, which uses huge high-powered radio towers that are much harder to overwhelm. Other solutions include magnetic and quantum systems that use variations in Earth's magnetic field to determine position without external signals.

Beyond jamming, GPS spoofing swaps the real signal for a fake one, quietly feeding a location that looks real but can guide users somewhere else entirely. This affects over 1,500 flights per day, and at sea ships are jumping implausible distances, briefly disappearing or reappearing in impossible locations, even on land. It is a systematic, geographically clustered distortion of reality both in the air and at sea.