Currently in the testing phase the EGNOS system is a joint project of the European Space Agency (ESA), the European Commission (EC), Eurocontrol, and the European Organisation for the Safety of Air Navigation. Like WAAS the system consist of a network of ground based ranging integrity monitoring stations (RIMS) that monitor GPS satellite data. The RIMS collect data on the GPS signal and transmit the data via land-based networks to central processing centers. The central processing centers then create a GPS correction message, taking into account selective availability (SA), GPS satellite orbit and clock drift, and signal delays caused by the atmosphere and ionosphere. These 'corrected' differential messages are then broadcast through a Geostationary Earth Orbit (GEO) satellite on the same frequency as the GPS signal across Europe. GPS receivers equipped to receive the signal then process the correction message for improved accuracy and integrity.

The EGNOS System Test Bed (ESTB) is currently underway and is expected produce a fully operation EGNOS system by 2004.

Learn more about the status of the EGNOS and the ESTB by visiting the  European Space Agency's Website .

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Related Sites

 FAA Global Positioning System Website 

 EGNOS System Test Bed Website