Since Russia’s full-scale invasion of Ukraine began in 2022, GPS glitches over the Baltic Sea have become a routine occurrence, throwing off the navigation systems of thousands of ships and flights. The working assumption in European capitals was that the source of this problem could be pinpointed to the highly militarized Russian exclave of Kaliningrad, where electronic warfare units and an array of signal spoofing antennae are wedged between Poland and Lithuania. If Google Maps suddenly started glitching on your morning jog around Warsaw or Vilnius, you could blame the Kremlin for causing you to be late for breakfast.
It turns out that the presumption was off by about 1,200 kilometers, all of it vertical. In a preprint study released on June 2, a team from the University of Texas and Stanford showed that the interference—sharp bursts of noise that disrupt a GPS receiver’s signal—ranged from Iceland to Italy, far too wide an area for any ground transmitter to cover. By analyzing raw data from Amsterdam and Trondheim, the researchers tracked the interference signal to within 5 meters of its source. They identified it as Cosmos 2546, part of a small Russian satellite constellation known as the Tundra array that watches for missile launches. The GPS blackouts clustered on weekday business hours, which is to say there was human involvement.
What remains unexplained is the intent. Was it deliberate jamming, an experiment or something else? Todd Humphreys, one of the lead researchers, told the science education channel Veritasium that he leans toward calling it “a periodic test of a capability that would be very damaging if it was deployed in anger.”