Every time a delivery truck follows a route, a pilot confirms an approach, or an emergency dispatcher locates a caller, a satellite navigation signal is quietly doing the heavy lifting. Global Navigation Satellite Systems — GNSS — have become so embedded in daily infrastructure that their absence would be felt almost immediately. That dependency, however, makes them a target.
Two types of attack, one common goal: disruption
The European Space Agency draws a clear line between two distinct forms of interference. Jamming overwhelms GNSS frequencies — used by systems such as Galileo, GPS, GLONASS, and BeiDou — with noise powerful enough to render receivers useless. Spoofing is subtler and arguably more dangerous: false position or timing data is broadcast to fool receivers into thinking they are somewhere they are not, while appearing to function normally.
Neither threat is hypothetical. Documented incidents in Northern Europe and the Middle East have shown that commercial aircraft, cargo vessels, and emergency response systems can all be affected. Some disruptions appear to be the unintended spillover of military jamming equipment; others show signs of deliberate, targeted interference designed to disorient or mislead.
New detection methods taking shape
ESA is pursuing several technical approaches to build greater resilience into navigation infrastructure. One of the most effective strategies involves cross-referencing signals from multiple constellations at once. When a receiver notices conflicting position data depending on which system it queries, that inconsistency itself becomes a red flag — an early indicator that spoofing may be underway.
Alongside multi-constellation monitoring, researchers are exploring the integration of inertial measurement units and non-satellite positioning technologies, including ground-based signal networks and onboard machine vision. The principle is straightforward: no single point of failure. If satellite data is compromised, an independent reference should catch the discrepancy before it causes harm.
Real-time spectrum analysis is another avenue drawing attention. By characterizing the signature of a jamming signal as it emerges, systems could theoretically issue warnings to nearby receivers before disruption fully sets in — a meaningful advantage for aviation and maritime safety, where reaction time is critical.
Strategic autonomy at stake
The technical dimension of this problem cannot be separated from its political context. For the European Union, Galileo is more than a navigation tool — it is an instrument of strategic autonomy. The system's restricted Public Regulated Service, designed for government and security use, incorporates encryption and signal protections that the open civilian service does not offer. That distinction is not incidental; it reflects a calculated response to exactly the kind of threats ESA is now working to counter more broadly.
Still, the challenge scales with the threat. Jamming hardware has become cheaper and more widely available, lowering the barrier for state and non-state actors alike to cause disruption. Whether civilian GNSS infrastructure can keep pace with that curve remains an open question — and one that agencies like ESA and their industry partners will need to answer with more than research papers alone.
