Global Navigation Satellite Systems (GNSS)

In line with the worldwide strategy defined by ICAO, the EUROCONTROL policy on GNSS is based on a gradual reliance on Satellite navigation that has as final goal its use as sole service, to the extent that this can be shown to be the most cost beneficial solution and if is supported by a successful safety and security analyses. The vision for implementing this policy is based on the combined use of signals coming from at least two constellations in diverse frequency bands. User receivers will process signals from different GNSS constellations in combination with augmentations depending on individual business cases and the phase of flight.

GNSS constellations

The Global Positioning System (GPS) is a U.S. space-based radionavigation system that provides reliable positioning, navigation, and timing services to civilian users on a continuous worldwide basis, freely available to all. GPS is being used with adequate augmentation, in many States as a positioning source an increasing number of for B-RNAV (Basic Area Navigation), NPAs (Non Precision Approaches) and RNAV (Area Navigation) approaches.

GLONASS is a GNSS constellation managed by the Russian Federation. The modernisation process for GLONASS is on-going and it is expected that 24 satellites will be operational by 2010. GLONASS Status.

Galileo is an initiative launched by the European Union (EU) and the European Space Agency (ESA) to deploy a worldwide constellation by 2013.

China, Japan and India are planning to deploy other GNSS constellations.

GNSS augmentations

There are 3 main types of augmentation to allow the use of GNSS applications in aviation: ABAS (Aircraft Based Augmentation Systems), GBAS (Ground Based Augmentation System) and SBAS (Satellite Based Augmentation System).

EGNOS is the European SBAS system. EGNOS is a project of the European Tripartite Group whose members are the European Space Agency, the European Commission and EUROCONTROL.