Julian Moxon/PARIS
Eurocontrol has developed an internet tool for helping pilots assess the availability of global positioning system (GPS) satellites for European operations.
The Augur system will provide all of the information needed to advise on GPS integrity, and, says Eurocontrol, will help aircraft operators to use GPS for standalone navigation in accordance with the requirements of the Joint Aviation Authorities.
The idea follows the introduction of a mandatory requirement issued by the European Civil Aviation Conference (ECAC) in April. This necessitates aircraft using the air traffic services route network to carry basic area navigation equipment to enable their position to be determined automatically to within 8km (5nm) of the desired track. Data come from existing ground-based sensors, and the GPS - but the GPS can only be used subject to satellite availability.
Several computer programs for availability prediction are already offered, but the information has to be interpreted manually. The Augur provides a means of checking GPSintegrity for the whole of ECAC airspace, as well as informing the user of the number of operational satellites. It is predictive, with accuracy relying on the latest information on the status of each satellite signal. Because the number of operational satellites can be reduced at any time without warning, Eurocontrol recommends the use of the system "as late as possible" in the flight planning process.
The Augur web page (http://augur.ecacnav.com) gives access to four modes: STATUS and VISIBILITY, for predicting the number of operational satellites, and AREA and ROUTE, for predicting outages of the GPS self-monitoring system, the Receiver-Autonomous Integrity Monitor (RAIM), either over an area or a specified route. The AREA mode, which Eurocontrol claims to be unique, provides a graphical overview of RAIM availability across the ECAC region, allowing users to quickly determine whether their flight will be disrupted.
Source: Flight International
