Galileo system of global satellite navigation system ("Galileo" system)

Galileo, with a total investment of 3.5 billion euros, is an independent civil global satellite navigation system in Europe, which provides high-precision and high-reliability positioning services, realizes completely non-military control and management, and can carry out navigation and positioning functions covering the whole world. The development of Galileo satellite positioning system by EU can reduce Europe's dependence on American military and technology and break the monopoly of American satellite navigation market. French President Jacques Chirac once said that without the Galileo plan, Europe "will inevitably become a vassal, first of all, science and technology, followed by industry and economy". Galileo project is a positioning scheme for medium-altitude circular orbit satellites. Galileo satellite navigation and positioning system will be completed before the end of 2007 and put into use in 2008. A total of 30 satellites will be launched, of which 27 are working satellites and 3 are backup satellites. The altitude of the satellite is 24 126 km, which lies in three orbital planes with an inclination of 56 degrees. In addition to 30 medium-altitude circular orbit satellites, the system also has two ground control centers. The first satellite of Galileo plan of EU was launched on February 28th, 2005, and the second satellite is expected to be launched on 20 15. Because Galileo plans to adopt the joint venture between public institutions and private enterprises in the European Union, private enterprises in various countries have not reached a compromise on the distribution of rights and interests. The EU spokesperson admitted that due to the above problems, the commercial operation of Galileo system has been postponed to 20 1 1 or even later. As a large-scale strategic international cooperation project, the implementation progress of Galileo Plan is related to many interests. So far, the EU has signed cooperative development agreements with China, Israel, the United States, Ukraine, India, Morocco and South Korea, and is negotiating cooperation with Argentina, Brazil, Mexico, Norway, Chile, Malaysia, Canada and Australia. China is the first non-EU country to sign Galileo cooperation agreement with the EU, with a total investment of 200 million euros. It can be said that, as one of the increasingly important global partners of the EU, China's participation in the Galileo program is in the economic and strategic interests of both China and Europe. Compared with the global positioning system (GPS) in the United States, Galileo system will have at least three advantages: first, its coverage area will be twice that of GPS system, and it can provide services for a wider range of people; Secondly, its ground positioning error is less than 1 m, and its accuracy is more than 5 times higher than that of GPS. In the words of experts, "GPS can only find the street, but Galileo can find the garage door"; Thirdly, Galileo system works in multiple frequency bands, which is more economical, transparent and open than GPS in civil field. Once the Galileo plan is realized, it will not only greatly facilitate the life of Europeans, but also bring considerable economic benefits to European industry and commerce. More importantly, Europe will have its own global satellite positioning system from now on, which will not only help to break the monopoly position of American GPS system and seize a favorable position in the global high-tech competition wave, but also create conditions for building the independent defense that Europe dreams of. Galileo system proposal 65438+1The meeting of European transport ministers held in June 1999 approved the allocation of 37 million euros for the completion of a new generation of satellite navigation system called Galileo. It was put into operation in 2008. 2. The choice and challenge of Galileo system How to develop Galileo system will be finally decided at the meeting of European transport ministers in the second half of 2000.

3.Galileo system performance Galileo system provides three levels of performance: global, regional and local.

4.4 service types. Gaiaieo system also defines three types of services: Open Access Service (OAS). Primary control access service (CAS 1) and secondary control access service (CAS 2).

5. Architecture of Galileo system The constellation of Galileo system can be composed of 9 geostationary satellites and 265,438+0 MEO satellites or 30 MEO satellites.

6.6 compatibility. Galileo system with GPS and GLONASS. Radio frequency compatibility is very important to realize the interoperability of the three systems: the systems cannot interfere with each other or reduce the performance of the receiver.