EGNOS and Galileo
European GNSS Activities
EGNOS:
EGNOS is Europe's first venture into satellite navigation. It will augment
the two satellite navigation systems now operating, the US GPS and Russian
GLONASS systems, and make them suitable for European safety critical applications
such as flying aircraft or navigating ships through narrow channels.
Consisting of three geostationary satellites and a network of ground stations,
EGNOS will achieve its aim by transmitting a signal containing information
on the reliability and accuracy of the positioning signals sent out by
GPS and GLONASS. It will allow users in Europe and beyond to determine
their position to within 5 m compared with about 15 m at present and will
quickly alert users of any satellite failures.
EGNOS is a joint project of the European Space Agency (ESA), the European
Commission (EC) and Eurocontrol, the European Organisation for the Safety
of Air Navigation. It is Europe's contribution to the first stage of the
global navigation satellite system (GNSS) and is a precursor to Galileo,
the full global satellite navigation system planned for development in
Europe.
EGNOS will become fully operational in 2004. In the meantime, a test signal,
broadcast by two Inmarsat satellites, allows potential users to acquaint
themselves with the facility and test its usefulness.
For more information on EGNOS, see http://www.esa.int
or http://www.esa.int/export/esaSA/navigation.html
Galileo:
Galileo is planned to be Europe's own global satellite navigation system, providing a highly accurate, guaranteed global positioning service under civilian control. It will be inter-operable with GPS and GLONASS, the two other global satellite navigation systems. This means that a user will be able to take a position with the same receiver from any of the satellites in any system.
By offering dual frequencies, Galileo will deliver positioning accuracy
down to 4 m. It will also guarantee availability of the service under
all but the most extreme circumstances and will inform users within six
seconds of a failure of any satellite. This will make it suitable for
applications where safety is crucial, such as aircraft landing.
Full-fledged service is planned to be operational by 2008 when 30 Galileo
satellites will be in position in circular orbits about 24,000 km above
the Earth. The first satellites will be launched in 2004 and by 2006 a
sufficient number should be in place to begin an initial user service.
The orbits (medium Earth orbits or MEOs) will be inclined at an angle
of 55-60 to the equatorial plane, giving very good coverage of latitudes
up to 75 Deg north, that is up to the North Cape and beyond.
27 of the Galileo satellites will be operational and three will be active
spares. The large number of satellites and the availability of the spares
will ensure that the loss of one satellite has no discernible effect on
the user. A few geostationary satellites may complement the MEO satellites.
About 14 ground stations positioned over the globe, will monitor the satellites'
positions and the accuracy of their on-board clocks. The ground stations
will be connected to central control facilities in Europe via a dedicated
communications network. The control facilities will compute the corrections
that need to be sent back up to the satellites via the ground stations.
The control facilities will also keep service providers, such as providers
of traffic management services, informed about the operating status of
the satellites.
For more information see http://www.galileo-pgm.org,
or http://www.galileosworld.com.
Regular newsletter updates are available on http://www.genesis-office.org.
The Galileo Insustry Day
The Galileo Industry Day was held in Brussels on 18 March 2003. With 600 participants including industry leaders, potential investors and users of Galileo from all over the world, the conference has been a great success. Please visit the website at: http://europa.eu.int/comm/dgs/energy_transport/galileo/partners/private_infoday_en.htm to learn more or download documents.