Implementation of a European infrastructure for satellite navigation: from system design to advanced technology evaluation

Europe is initiating the Galileo programme, targeting the implementation of a navigation system independent and interoperable with GPS and GLONASS. Galileo will bring Europe a wide range of political, economical and industrial benefits. The architecture of Galileo is based on an MEO constellation, possibly completed with Geostationary satellites. Possible constellations are 24 MEO + 3-9 GEO depending on the area to be covered, or 30 MEO only. The integrity concept is regional, like in EGNOS. One of the major issues is to define adequate frequency bandwidth to be used for broadcasting the navigation signal to the users. Several scenarios are being considered, depending on the possible level of co-operation with US and/or Russia. System key issues are integrity data generation, orbit-determination/synchronization, and constellation design. The major challenges to face are to propose an innovative concept offering advantages to the users compared to GPS, while keeping costs low and using well-proven technologies not to endanger the programme implementation. In order to do so, it is proposed to take advantage of several space programmes implemented by Alcatel, at ground and space segment levels. EGNOS heritage is, of course a major heritage for the development of the Galileo ground segment. Payload design is based on a direct heritage from the MTSAT products, and satellite design is taking advantage of the Alcatel product line including Proteus, Skybridge, Spacebus and Globalstar. Galileo will take full benefit of the expertise gained through all these programmes. This expertise and the resulting Galileo design is described in this paper. Copyright (C) 2000 John Wiley & Sons, Ltd.