European Geostationary Navigation Overlay Service (EGNOS)

Satellite navigation is currently based on the US GPS and Russian GLONASS military satellite navigation systems. An evolution of these systems is known as the Global Navigation Satellite System (GNSS), which provides an overlay function and supplementary services of Global Satellite Augmentation System (GSAS). In this paper is presented the major contribution to GNSS-1 EGNOS system as an important initiative by European Space Agency (ESA), the European Commission (EC) and Eurocontrol. The EGNOS Space Segment, Ground Infrastructure and User Segment, which transmits overlay signals almost identical to those of GPS or GLONASS and provides civilian transport requirements for high-operating Integrity, Continuity, Accuracy and Availability (ICAA) are discussed. The EGNOS system is fully interoperable within the USA WAAS and Japanese MSAS. The built-in expansion capability of EGNOS as a Regional Satellite Augmentation System (RSAS) will extend its service areas within entire Europe ground and sea environments.