Four European countries are to test automatic dependent surveillance – broadcast (ADS-B) systems to validate their potential as an alternative to conventional radar.
Airspace authorities in Germany, Ireland, the Netherlands and the UK will each perform a two-year trial with the system.
The ADS-B ground stations, developed by the UK division of US manufacturer Raytheon, will be tested as part of the Eurocontrol Cascade initiative to validate datalink-based surveillance and communications concepts. The Raytheon system is based on 1090MHz datalink. “Introduction of ADS-B would enable the safe reduction in aircraft separation where there is currently no radar coverage,” says Raytheon.
Eurocontrol’s decision to perform the trial follows a study – commissioned by UK airspace authority National Air Traffic Services and released at the end of April – which examines the potential of ADS-B to provide supplemental coverage to radar around London and Scotland.
The study compares the present radar-based system with a proposed ADS-B surveillance network to be deployed around 2015. It takes into account the projected change in traffic levels, as well as technical differences between the two systems, such as update rate, probability of detection, levels of accuracy, and the differences in types of data available through ADS-B and radar.
The study concludes that “appropriately placed” ADS-B ground stations with 100nm (185km) range, used in conjunction with radar, could provide complete coverage of south-east UK terminal airspace above flight level 55 (5,500ft/1,680m).
Such systems would be able to provide a track-update rate “equal to or exceeding radar” and even exceed radar’s accuracy. “The increased frequency of use of separations due to increased traffic levels in the future scenario can be ‘traded-off’ with the increased accuracy of ADS-B, to show that the proposed future ADS-B scenario has lower collision risk than the reference radar scenario.”
DAVID KAMINSKI-MORROW/LONDON
Source: Flight International
