(European Geostationary Navigation Overlay Service) is a European project that provides a form of differential correction signal for GPS. Corrections are provided for the territory of Europe and are important for eliminating errors, which are inevitably burdened with broadcast signals. Differential signal processing in GNSS receivers give more precision to positioning.
EGNOS is an application of Satellite Based Augmentation System (SBAS), which is being developed by the European Space Agency (ESA), European Commission (EC) and European Organization for the Safety of Air Navigation (EUROCONTROL).
The system is composed of 34 ground Ranging and Integrity Monitoring Station (RIMS), which are located in Europe and continuously monitors the data transmitted from satellites in the GPS. The result is continuously transmitted to a secure data network to one of the Master Control Centres (MCC). Here, the data is adjusted and evaluated the information on the status of the GPS satellites and the measurement errors caused by the state of Earth's atmosphere. The data is then transmitted to the three network broadcasters. Broadcasting stations transmit data to three satellites in geostationary orbit. These satellites returning data back to Earth, where the receiver corrects them according to data received from GPS satellites. In practice, the error should be at least 99% measuring less than 1.5 meters.
EGNOS offers three basic services:
- Open Service (OS) - available free to the public for mass-market receivers and common user applications;
- EGNOS Data Access Service (EDAS) - offered on a controlled access basis (e.g. through Internet or mobile phones) to customers who require enhanced performance for professional use;
- Safety of Life Service (SoL) - for safety-critical transport applications, namely in civil aviation - this service provides enhanced and guaranteed performance and features an integrity warning system.
- 1994 - European Council approves the launch of the EGNOS programme
- 1996 - September: Launch of Inmarsat-3 F2 AOR-E (PRN 120), a telecommunications satellite carrying an EGNOS transponder
- 1998 - February: Launch of Inmarsat-3 F5 IOR-W (PRN 126), a telecommunications satellite carrying an EGNOS transponder. EGNOS mission requirements are set.
June: Council of the European Union confirms that EGNOS is an integral part of Europe’s satellite navigation policy.
EGNOS will be adapted as needed be to follow the SBAS International Civil Aviation Organization international standard upgrades.. Services should be extended determinedly to other parts of the world in the long term.
- une: First master control centre (MCC) was inaugurated at Langen, Germany.
- December: first EGNOS test signals from space broadcast.
- June: Council of the European Union confirms that EGNOS is an integral part of Europe’s satellite navigation policy.
- 2005 - EGNOS version 1 (v1) starts initial operations phase by broadcasting a continuous signal.
- 2006 - EGNOS version 2.1 is deployed, implementing the EGNOS Data Server which gives real time access to EGNOS Ranging and Integrity Monitoring Station (RIMS) measurements and message data to service providers. V2.1 also extends EGNOS coverage to the north of Africa
- June-July: Qualification of EGNOS v2.2, which allows the implementation of the Regional Extension Module concept for further extending EGNOS coverage, including to Africa.
- October: EGNOS v2.2 deployed.
- March: EGNOS Data Access Server (EDAS) service available as a beta test.
- April: Assets transferred from ESA to the European Commission on behalf of the European Community. EGNOS operations, services provision and maintenance entrusted to ESSP SaS.
- October: EGNOS OS declared operationally ready. Entry into operations of Open Service.
- Launch of GSA web portal for user communities and developers of applications.
- Conclusion of assessment phase for EDAS and the start of the service’s market phase.
- Three more RIMS are scheduled to be deployed in Agadir (Morrocco), Athens (Greece) and Alexandria (Egypt). The deployment is designed to extend EGNOS signal coverage to northern Africa
- Processing improvements are scheduled for the EGNOS signal, for example iono algorithm pre-processing fine tuning
- Safety-of-Life service launched after the Certification of the ESSP as Air Navigation Service Provider and the System Declaration of Verificatio.
- 2012 - 2013 - Scheduled deployment of EGNOS v3 to cover the Multi-Constellation Regional System (MRS) concept and implement a GPS L5 augmentation service.