Air traffic surveillance is essential to keep skies safe and flights efficient. Today, most surveillance systems rely on ground-based radars and ADS-B (Automatic Dependent Surveillance–Broadcast) receivers, which work very well over land. However, in oceanic and remote areas, building and maintaining this infrastructure is difficult or impossible. As a result, aircraft flying in these regions must follow wider separation rules, limiting airspace capacity, hindering optimal routing, and leading to higher fuel consumption and increased emissions. This situation is at odds with Europe’s goals for greener aviation, better airspace use, and seamless global connectivity.
To extend surveillance into these regions, space-based ADS-B systems have been deployed. These use satellites in low Earth orbit (LEO) to receive position data from aircraft, route them through an intersatellite network, and downlink the data to ground systems when feasible. This represents a major step forward. However, these systems depend entirely on GNSS (Global Navigation Satellite Systems)—such as GPS or Galileo—which can be affected by jamming, spoofing, or signal errors. GNSS vulnerabilities are particularly relevant in today’s unstable geopolitical environment. This dependency is further aggravated by the lack of an independent method to verify aircraft positions, which is a key limitation for adopting tighter safety standards or performance-based surveillance (PBS) in non-radar areas.
This is where SATERA comes in. The project aims to develop and demonstrate a new type of space-based surveillance system that combines traditional ADS-B with Enhanced Multilateration (E-MLAT). This involves equipping satellites with receivers capable of extracting Time of Arrival (ToA), Frequency of Arrival (FoA), and Angle of Arrival (AoA) from aircraft signals to calculate positions independently of GNSS. This extra layer of information enables cross-checking and enhances the integrity and trust of surveillance data.
SATERA will design and test this concept through a combination of fast-time simulations (FTS) and laboratory experiments, aiming to reach Technology Readiness Level 2 (TRL2). The system’s performance will be evaluated against standards such as EUROCAE ED-142A, focusing on metrics like update rate, latency, and horizontal accuracy.
By enabling dual and independent surveillance channels from space, SATERA supports the SESAR (Single European Sky ATM Research) vision of safer, smarter, and more sustainable air traffic management—especially in airspace without ground-based surveillance infrastructure. The project will contribute to reduced aircraft separation, improved routing efficiency, lower environmental impact, and provide valuable input for future regulation and deployment of space-based solutions across Europe and beyond.
