Next week, Europeans will know whether they are to have their own global satellite navigation system. On 20 December, Europe’s transport ministers and the council of the European Space Agency will decide independently whether to go ahead with Galileo, the Euro 3.2 billion global satellite navigation system that has been under definition for the past 18 months.
Navigation satellites already guide ships, planes and spacecraft. They provide the surveying reference for roads, bridges and cities and the time reference for power and telecommunications networks. Quite soon, mobile phones will be equipped with navigation receivers, opening the way for a wide range of new personalised services.
At present, however, satellite navigation users in Europe have no alternative other than to take their positions from US GPS or Russian GLONASS satellites. Yet the military operators of both systems give no guarantee to maintain an uninterrupted service. Galileo will provide European navigators with an independent system under civilian control which will be guaranteed to operate at all times, bar the direst emergency.
The European Commission and the European Space Agency have been defining the Galileo system. The Commission has taken responsibility for policy and the definition of the system architecture, while the Agency has concentrated on the definition of the satellite constellation, ground segment and associated technology.
The two organisations have drawn up a baseline design, which has already been presented to the transport ministers and a number of other committees. The overall system architecture consists of 30 satellites in medium earth orbit (MEO), an extensive network of ground stations, and local and regional service centres.
The satellites will orbit at an altitude of about 23,000 km. Their positions will be monitored continuously by the ground stations, which will send integrity data to them. The local and regional service centres will be operated by companies providing a variety of positioning and timing services for many types of user. These include transport authorities, companies and utilities requiring precise timing information, and individual users of mobile phones that incorporate satellite navigation receivers.
The signals broadcast by the satellites will be geared to three different types of user. The basic signal will be free of charge and available to all users. Those requiring a more accurate service with guaranteed availability will pay to access a data stream modulated on the basic signal. And finally a highly secure signal will be available to public authorities for security and safety critical applications such as the regulation of air, sea and road transport.
The total cost of developing Galileo is estimated at Euro 3.2 billion. Euro 1.1 billion of that will be spent on the development and validation phase which will finish at the end of 2005. The rest will be spent in 2006 and 2007 when most of the satellites will be launched.
The development and validation phase will be financed out of the public purse and the operational phase after 2007 is expected to be financed entirely privately. The interim, deployment phase, is likely to be financed from a mixture of public and private sources.
Further details on the public/private finance package and the setting up of a Galileo Agency to build the system will be presented in a final paper on which the Transport Council will vote on 20 December.