What is EGNOS?

EGNOS or the European Geostationary Navigation Overlay Service, is Europe’s regional Satellite-Based Augmentation System (SBAS). SBAS improves the accuracy and reliability of GNSS information by correcting signal measurement errors and by providing information about the accuracy, integrity, and availability of its signals.

EGNOS is a joint project of the European Space Agency (ESA), European Commission and Eurocontrol, and European Organisation for the Safety of Air Navigation. This system consists of 40 ground stations spread across Europe and 3 geostationary satellites. Since the location of the ground stations is know, they can be used to identify any errors being transmitted by the GNSS Constellations (In the case of Europe, this would be Galileo). The measured GNSS errors (if any) are then broadcast using geostationary satellites to serve as an augmentation, or overlay signal for the original GNSS signal. This way GNSS receivers can compensate for any errors in the original GNSS signal they are receiving. This service is freely available in Europe and is open for use to anyone with an EGNOS-enabled satellite navigation receiver.

EGNOS - How does it Work?