Steve Nichols
The USA's GPS system is seen as something of a mixed blessing in Europe.
Although it is an excellent navigation tool costing nothing to use, it is also relatively inaccurate and under the control of the US military. Glonass is the Russian version, also out of European control.
But as this air show proves, just about every navigation system on sale uses GPS or Glonass, including automatic dependent surveillance - broadcast (ADS-B), enhanced ground proximity warning systems (EGPWS) and future "free flight" and automated landing systems.
Europe would like to launch its own global navigation satellite system (GNSS). Called GNSS-2, and using the Galileo satellite, the project is not going to happen until 2008 at the earliest.
Solution
But the European Space Agency (ESA) is demonstrating its plans for a solution that will improve or augment the existing GPS and Glonass services and still work with the European-launched satellites if and when they are launched.
ESA is presenting the European geostationery navigation overlay (EGNOS) project - its wide area augmentation system (WAAS) which uses satellite ground stations to send updated GNSS information to give GPS/Glonass an accuracy of about 7m (21ft).
EGNOS uses geostationary satellites to relay extra information, enabling aircraft to determine their actual positions with greater precision.
But with EGNOS, the position of the geostationary satellite must be known very accurately before it can be used for navigation.
The new, more accurate, information is transmitted to users, currently via two Earth stations in Italy and France.
Source: Flight Daily News