The European Space Agency (ESA) has announced that its Proba-V satellite has successfully picked up signals from thousands of aircraft around the globe. The findings of the mission, which was primarily tasked with watching changes in vegetation across the planet, could pave the way for a more accurate air traffic control system.
Since launching in 2013, the probe has picked up over 25 million positions from more than 15,000 individual aircraft. Though the teams are still in the process of corroborating the findings with ground-based recordings, the successful detections serve as a proof of concept, demonstrating the feasibility of using orbital satellite constellations for operational aircraft monitoring.
The detections were made possible by a receivers placed aboard the satellite by DLR and SES TechCom, designed to pick up signals from aircraft carrying Automatic Dependent Surveillance Broadcast (ADS-B) equipment, which is expected to become a requirement for all aircraft operating in European airspace.
The ADS-B signals weren't designed to be picked up from space – they're actually beamed sideways rather than omnidirectional – so, it can be difficult to detect them from orbit. At present, the system is better able to detect aircraft carrying certain makes and models of the ADS-B system, but the team is actively working to improve the receiver's capabilities.
The project is largely focused on providing mapping to areas of the planet that currently aren't catered for by radar networks. However, its accuracy could also allow air traffic controllers to reduce the minimum distance between aircraft in densely packed airspace, safely increasing air traffic capacity.
To confirm the accuracy of the system, both SES and DLR are collaborating with air navigation service providers in various countries to check the Proba-V stats against aircraft positions recorded from the ground.
The lone Proba-V satellite covers an area of around 1,500 x 750 km (932 x 466 miles) at any one time, meaning numerous such probes would be necessary to provide uninterrupted coverage.
It looks likely that the technology could see action in the near future, with operational ADS-B receivers making their way onto Iridium Communications' commercial IridiumNEXT constellation satellites, scheduled to begin launching in 2015.
Sources: ESA, Iridium Communications Inc.
