By Davide Noli and Massimo Mungiello
The European Geostationary Navigation Overlay Service (EGNOS) is Europe’s first venture into satellite navigation. It augments the positioning signals provided by the USA’s GPS global navigation satellite system and makes them suitable for safety critical applications such as flying aircraft or navigating ships through narrow channels.
Consisting of three geostationary satellites and a network of ground stations, EGNOS achieves its aim by transmitting a signal containing information on the reliability and accuracy of the positioning signals sent out by GPS. It allows users in Europe and beyond to determine their position to within 3 metres, compared with about 17 metres for GPS.
EGNOS has been developed through a tripartite agreement between the European Space Agency (ESA), the European Commission (EC) and Eurocontrol, the European Organisation for the Safety of Air Navigation. The agreement was signed in June 1998. It is Europe’s first activity in the field of Global Navigation Satellite Systems (GNSS) and is a precursor to Galileo, the full global satellite navigation system under development in Europe.
EGNOS entered its pre-operational phase in the summer of 2005.
The Open Service, for applications where human life is not at stake, such as personal navigation, goods tracking and precision farming, has been available since October 2009.
The Safety-of-Life Service, where human lives depend on the accuracy and integrity of the signals, became available for its primary purpose of aircraft navigation (beginning with vertical guidance for landing approaches) in March 2011.
EGNOS also provides a terrestrial commercial data service: EDAS (EGNOS Data Access Service).