Developed as a viable low-cost alternative to conventional radar, space-based automatic dependent surveillance-broadcast (ADS-B) can monitor and control aircraft with greater precision and in areas of airspace which currently have no radar coverage. Because of its high-precision capabilities, ADS-B has the potential to maximise airspace capacity by reducing separation between aircraft.
Between 2016 and 2018, the SALSA project evaluated the performance and value of ADS-B in the context of enhanced surveillance and separation standards revision in non-radar airspace.
Specifically, the project looked at what conditions were required for the introduction of lower separation minima on transoceanic flight routes, particularly between Europe and the US, where traffic density is considerably higher in the morning and evening peak periods.
By combining space-based ADS-B with other sources of surveillance-based ground, air and oceanic relays, SALSA developed a system-of-systems approach. It found that space-based ADS-B, when augmented with enhanced controller-pilot data links, can maximise the use of enhanced surveillance and reap the operational benefit of revised separation minima.