With 10% of European GDP enabled by satellite navigation, the economic impact of GNSS interference is significant. In the second quarter of 2025, more than 10 000 ships were reported as being impacted by malicious interference globally, marking an eightfold increase as compared to the first quarter of 2025.

Interference not only disrupts navigation on land, air and sea, but it also poses safety issues and economic losses as many ship systems, including fire safety and emergency beacons, as well as critical infrastructure such as power grids, are linked to GNSS. In 2025, a joint statement issued by several United Nations agencies called for the protection of signals from harmful interference.

GNSS interference can take many forms. In jamming, GNSS signals are drowned out by stronger signals. In spoofing, they are faked to mislead the receiver. GNSS interference also occurs naturally due to space weather. Charged particles in the ionosphere, influenced by the Sun, can disrupt or delay signals.

Finding ways to increase the resilience of satellite navigation systems is a top priority for ESA. As system development prime for the European Union, ESA is responsible for making existing systems such as Galileo and EGNOS more resilient.

Focused on innovation, ESA is building resilience by exploring a multi-layer system-of-systems for GNSS (for example through Celeste LEO-PNT), developing new technologies through research and development, and testing them at events like Jammertest.

The Navigation Innovation and Support Programme (NAVISP) facilitates innovation in positioning, navigation and timing (PNT), supports industrial competitiveness and assists Member States in their national strategy. Recently, NAVISP has supported three activities that develop new ways to monitor and map GNSS interference.