Feature

Europe’s global navigation satellite system


Payload fairing of the Soyuz-Fregat launcher
 
 
 
 
The global navigation satellite system developed under the Galileo Programme will provide Europe a fully autonomous satellite-based positioning, navigation and timing capability, for global high performance services.
 
By offering dual frequencies as standard, Galileo will deliver real-time positioning with metre accuracy, which is unprecedented for a publicly available system. Furthermore, Galileo will be interoperable with other global navigation satellite systems, notably with the US GPS, which means that a user will be able to take a position with the same receiver from any of the satellites in any combination.
  
 
 The Galileo programme has been structured according to three main phases:

1-Experimental phase (two satellites)

Two experimental satellites, GIOVE-A and GIOVE-B, launched respectively December 2005 and April 2008 have characterised and verified the critical technologies needed by Galileo within the medium-Earth orbit (MEO) environment. They have also reserved radio frequencies set aside for Galileo by the International Telecommunications Union. Both successfully completed their missions and are no longer operational.

2-In-Orbit Validation (IOV) phase (four satellites)

The aim of the Galileo In-Orbit Validation (IOV) phase is to validate the system design using a reduced constellation of four satellites – the minimum required to provide exact positioning and timing at the test locations – along with a limited number of ground stations. The first two IOV satellites were carried into orbit by a Soyuz launcher from Europe's Spaceport in French Guiana on 21 October 2011. The second pair was launched on 12 October 2012.

3-Full Operational Capability (FOC) phase (four IOV satellites plus 26 FOC satellites)

Launched in parallel to the In-Orbit Validation (IOV) phase, the Full Operational Capability (FOC) phase will lead to the deployment of the remaining ground and space infrastructure. It includes an intermediate initial operational capability (IOC) milestone with 18 satellites in operation (four IOV satellites plus 14 FOC satellites). Early services with reduced performance or for demonstration purpose will be provided from mid-2014.
  
 
 Galileo offered services

Signals in-space stemming from the Galileo satellites, will offer new classes of worldwide services to cover the widest range of user needs, including professional users, scientists, mass-market users and public regulated domains:

  • the Open Service (OS) is free of charge to the user and provides positioning and synchronisation information intended mainly for high-volume satellite navigation applications;
  • a contribution, by means of Galileo OS signals and/or in cooperation with other satellite navigation systems, to integrity monitoring services aimed at users of Safety-of-Life applications in compliance with international standards;
  • the Commercial Service (CS) for the development of applications for professional or commercial use by means of improved performance and data with greater added value than those obtained through the Open Service;
  • the Public Regulated Service (PRS) restricted to government–authorised users, for sensitive applications that require a high level of service continuity, free of charge for EU Member States, the Council, the Commission, the European External Action Service and EU agencies. The PRS uses strong, encrypted signals;
  • a contribution to the Search and Rescue Support Service (SAR) of the Cospas-Sarsat system by detecting distress signals transmitted by beacons, locating these beacons and relaying messages to them.

  
 
  
Last update: 22 January 2013


More information

 •  European Commission (http://ec.europa.eu/enterprise/policies/space/galileo/index_en.htm)
 •  European Space Agency (http://www.esa.int/esaNA/index.html)
 •  GNSS Agency (http://www.gsa.europa.eu/)
 •  European Satellite Services Provider (http://www.essp-sas.eu/)