3.3.2 ヨーロッパの動向
以下の情報は、European Space Agencyのホームページ(http://www.esa.int/)のPress Releasesから引用した。
3.3.2.1 欧州衛星航法システムが次のステップへ
ESAのPress Release(Nr.14-2000-Paris, 29 February 2000)から抜粋
“A step forward in European satellite navigation systems”
The European Space Agency, the European Commission and the European Organisation for the Safety of Air Navigation (Eurocontrol), are together making concrete progress in the development of a Global Positioning and Navigation Satellite System, dubbed GNSS.
The GNSS program is being carried out in two stages: GNSS-1, the first generation system, based on signals received by the existing American GPS and Russian Glonass constellations, and GNSS-2, the second generation, that will provide improved navigation and positioning services to civil users. Galileo will be Europe's contribution to GNSS-2.
Within GNSS-1, Europe is contributing EGNOS, the European Geostationary Navigation Overlay System, aimed at augmenting the performance of GPS and Glonass in terms of precision and data integrity. EGNOS is now becoming a reality as a test bed - a simplified version of the fully fledged system has recently been readied by Alcatel Space, the prime contractor leading the international industrial team which is developing the system.
The system is based on use of ground infrastructure and three geostationary satellites (Inmarsat 3 Indian Ocean Region (IOR) and Atlantic Ocean Region East (AOR-E), and, in future, ESA's Artemis telecommunications satellite). These spacecraft are equipped with dedicated navigation transponders to augment the positioning services currently offered by the GPS and Glonass constellations. The EGNOS ground infrastructure will be deployed over more than 40 sites, mostly in Europe. The ground infrastructure for the pre-operational version has already been deployed at many sites around Europe: France, Iceland, Italy, the Netherlands, Norway, Spain, Turkey, United Kingdom and at two sites outside Europe: Kourou (French Guiana) and Hartebeeshoek (South Africa).
The EGNOS system will be qualified at the end of 2003 and will provide in Europe an operational satellite navigation service which will later be improved with the operational introduction of Galileo (in 2008). Similar systems, namely the Wide Area Augmentation System (WAAS) and the MTSAT Satellite based Augmentation System (MSAS) are being developed by the USA and Japan respectively. EGNOS, WAAS and MSAS will be fully interoperable.
