Scientists mapped a covert space‑based source that has jammed GNSS receivers across Europe, Greenland, and Canada since 2019. The GNSS interference, visible as wide‑area signal drops, forces navigation systems to recalibrate and undermines aviation and maritime safety. Researchers used a global network of reference stations to track the anomaly.

From 2019 to 2026, analysts developed a received‑power detection framework that flags sudden signal loss. They mapped the events' timing, frequency, and geographic spread, revealing a pattern that points to a constellation of Russian early warning satellites. The study blends power metrics with time‑difference‑of‑arrival data to pinpoint the culprit.

The detection system relies on a simple power threshold, but the real breakthrough lies in combining it with triangulation from multiple ground stations. This dual‑technique approach eliminates false alarms and confirms that the interference originates from Molniya orbits, notorious for their high‑altitude, highly elliptical paths that cover vast swaths of the northern hemisphere.

Identifying the source as Russian early warning satellites has immediate policy implications. It signals that space‑based jamming can reach continents in seconds, bypassing ground‑based mitigation. Governments must now tighten spectrum protection and invest in resilient GNSS architectures that can withstand high‑altitude interference without disrupting critical infrastructure for aviation and maritime operations today and safety in.