Shipping faces GPS blackout: Seafarers must navigate without satellites
A Danish researcher warns GNSS interference is now a perpetual threat.
The shipping industry can no longer rely on GPS as a dependable navigation tool, warns a Danish researcher who has developed a system to track satellite interference from space. Kian Bostani Nezhad, a PhD researcher at the Technical University of Denmark (DTU), says GNSS disruption has become a “perpetual problem” affecting vessels in key maritime regions, urging crews to revive traditional navigation methods.
Nezhad’s platform, SAT-JAM, launched in September, uses data from European Space Agency satellites to map where spacecraft experience GNSS interference. However, he stresses the system does not pinpoint the origin of jamming or spoofing, only where satellites detect degraded signals. “The actual source and the measurement can be far apart, due to the high altitude of satellites,” he explains.
Satellites at 400-600 km altitude show widespread interference: gnss interference
His platform, inspired by GPSJam, a website tracking aircraft interference, uses publicly available data from European Sentinel satellites, updated as new observations emerge.
“I heard a spacecraft operator complain about their spacecraft having problems with GNSS over Europe,” Nezhad recalls. Intrigued, he analysed navigation data from low-Earth-orbit satellites and found consistent evidence of interference. His work, presented at the Advanced Maui Optical and Space Surveillance Technologies conference in March, underscores the urgency of addressing the issue.
Britain urges crews to prepare for GPS outages
The warnings align with recent guidance from Britain’s Maritime and Maritime and Coastguard Agency (MCA), which earlier this month cautioned shipowners that satellite navigation is no longer reliable in major shipping regions. The MCA’s advice highlights growing threats in the Baltic, Black Sea, Middle East Gulf, and East Asia, where jamming and spoofing disrupt everything from ECDIS and AIS to autopilots and port systems.
The MCA recommends regular navigation drills, alternative positioning methods, and heightened awareness of equipment vulnerabilities to mitigate risks. Nezhad’s research extends beyond interference tracking.
Asked for practical advice, Nezhad offers two key recommendations. First, shipowners should invest in controlled reception pattern antennas (CRPA), which can suppress interfering signals. Second, and more fundamentally, seafarers must relearn how to navigate without GNSS. “I know it is easier said than done, but GNSS interference has become a perpetual problem,” he stresses. The shift in mindset is critical.
“GNSS interference has become a perpetual problem. Everyone who uses GNSS must change their mindset from GNSS being a primary and dependable navigation solution, to it being a supplement to other navigation methods.”
Kian Bostani Nezhad·PhD researcher at the Technical University of Denmark
Sign up free to ask CAMAL AI for a summary, the key points or anything else about this story.
Related stories
CAMAL AI
Financial Ports Newsletter
The maritime economy, every morning
Ports, shipping and freight markets in one short email. Free.
