Who cares about the Baltic Jammer? – Terrestrial Navigation in the Baltic Sea Region

Reports of GNSS interference in the Baltic Sea have become almost routine — airplanes losing GPS, ships drifting off course, and timing systems failing. But what happens when a group of engineers decides to build a navigation system that simply *doesn’t care* about the jammer? Since 2017, we’ve been developing **R-Mode**, a terrestrial navigation system that uses existing radio beacons and maritime infrastructure to provide independent positioning — no satellites needed. In this talk, we’ll share our journey from an obscure research project that “nobody needs” to a system now seen as crucial for resilience and sovereignty. Expect technical insights, field stories from ships in the Baltic, and reflections on what it means when a civilian backup system suddenly attracts military interest.