The US firm Aireon says its new satellite surveillance network is now fully live and being trialled over the North Atlantic.
The system employs a constellation of 66 spacecraft, which monitor the situational messages pumped out by aircraft transponders.
These report a plane’s position, altitude, direction and speed every eight seconds.
ncreasing numbers of planes since the early 2000s have been fitted with Automatic Dependent Surveillance Broadcast (ADS-B) transponders. US and European regulators have mandated all aircraft carry this equipment as of next year.
ADS-B pushes out a bundle of information about an aircraft – from its identity to a GPS-determined altitude and ground speed. ADS-B was introduced to enhance surveillance and safety over land, but the messages can also be picked up by satellites.
Aireon has receivers riding piggyback on all 66 spacecraft of the Iridium sat-phone service provider. These sensors make it possible now to track planes even out over the ocean, beyond the visibility of radar – and ocean waters cover 70% of the globe
in the North Atlantic, traditional in-line safe separation distances will eventually be reduced from 40 nautical miles (80km) down to as little as 14 nautical miles (25km). As a result, more aircraft will be able to use the most efficient tracks.
“Eight out of 10 flights will now be able to fly without any kind of speed restriction compared with the far less efficient fixed-speed environment we previously had to operate within,” Mr Rolfe said. “These changes, made possible by Aireon, will generate net savings of $300 in fuel and two tonnes of carbon dioxide per flight.”
However, any carbon dividend is likely to be eaten into by the growth in traffic made possible by the introduction space-based ADS-B. Today, there are over 500,000 aircraft movements across the North Atlantic each year. This is projected to increase to 800,000 by 2030.