Science Fair Project Encyclopedia
Galileo positioning system
The Galileo positioning system (not to be confused with, or abbreviated to, GPS) is a planned civil satellite navigation system, intended as a European alternative to the military-controlled United States Global Positioning System (GPS). Usage of the acronym "GPS" in this article refers only to the existing United States system.
The first stage of the Galileo program was agreed upon officially on May 26, 2003 by the European Union and the European Space Agency. The system is intended primarily for civilian use, unlike the US system, which is run by and primarily for the US military. The US reserves the right to limit the signal strength or accuracy of the GPS systems, or to shut down GPS completely, so that non-military users cannot use it in time of conflict. The precision of the signal available to non-military users was limited before 2000 (a process known as selective availability). The European system will not (in theory) be subject to shutdown for military purposes, will provide a significant improvement to the signal available from GPS, and will, upon completion, be available at its full precision to all users, both civil and military.
The European Commission had some difficulty trying to secure funding for the next stage of the Galileo project. European states were wary of investing the necessary funds at a time of economic difficulty, when national budgets were being threatened across Europe. Some states, such as France and Italy, strongly supported Galileo because it would demonstrate an end to reliance on United States technologies. Other states, particularly Germany, the Netherlands, and the United Kingdom, felt that it would be better to continue getting the service for free from the US, rather than paying for it themselves. Following the September 11, 2001 Terrorist Attack, The United States Government wrote to the European Union opposing the project, arguing that it would end the ability of the US to shut down GPS in times of military operations. On January 17, 2002 a spokesman for the project sombrely stated that "Galileo is almost dead" as a result of US pressure.
A few months later, however, the situation changed dramatically. Partially in reaction to the pressure exerted by the US Government, European Union member states decided it was important to have their own independent satellite-based positioning and timing infrastructure. All European Union member states became strongly in favour of the Galileo system in late 2002 and, as a result, the project actually became over-funded, which posed a completely new set of problems for the companies involved (German nationalism was probably also a main factor).
The European Union and European Space Agency then agreed in March 2002 to fund the project, pending a review in 2003 (which was finalized on May 26, 2003). The starting cost for the period ending in 2005 is estimated at EUR 1.1 billion. The required satellites - the planned number is 30 - will be launched throughout the period 2006-2008 and the system will be up and running and under civilian control from 2008. The final cost is estimated at EUR 3 bn, including the infrastructure on Earth, which is to be constructed in the years 2006 and 2007. At least two thirds of the cost will be invested by private companies and investors, the remaining costs are divided between the European Space Agency and the European Union. An encrypted higher bandwidth Commercial Service with improved accuracy will be available at an extra cost, while the base Open Service will be freely available to anyone with Galileo compatible receiver.
The European Union has agreed to switch to a range of frequencies known as Binary Offset Carrier 1.1 in June 2004, which will allow both European and American forces to block each other's signals in the battlefield without disabling the entire system.
Political implications of Galileo project
As well as being an impressive technological achievement and a hugely practical tool, Galileo will be a political statement of European technological independence from the United States. A strong motivator for seeking technological independence is the policy of the United States government to employ only American companies for the building of components for the GPS.
Galileo Satellite Test Beds 2A and 2B
ESA and GJU aim to launch two satellites, GSTB-2A and GSTB-2B, by March 2005. GSTB-2A, built by SSTL, is basically a transmitter beacon, while GSTB-2B has an evovled payload which includes two atomic clocks. In both cases the primary objective is achieving the ITU frequency-filing requirements. GSTB-2B also has clock and MEO environment characterisation objectives, as well as Signal-In-Space and receiver experiments. GSTB-2B used a Proteus bus (Alcatel, France), a Rubidium atomic clock from Timex (Switzerland) and the first Passive Hydrogen Maser atomic clock used in space, from Galileo Avionica (Florence, Italy). GSTB-2B is integrated in the Alenia constellation facility "Globalstar" in Rome, the only such facility in Europe.
The European geostationary navigation overlay system (EGNOS) is intended to be a precursor to Galileo. EGNOS is a system of satellites and ground stations designed to increase the accuracy of the current GPS and GLONASS in Europe. Eventually, they will be used for Galileo too. Alcatel is the prime contractor for EGNOS. Either the Eurely alliance or the iNavsat consortium will likely operate Galileo once it becomes operational.
- Official EU Galileo Project website
- Official website Galileo Joint Undertaking
- Europe GPS Plan Shelved – By Steve Kettmann, Wired Magazine, 17 January 2002
- Green light for Galileo project – BBC News, 26 March 2002
- China joins EU's satellite network – BBC News, 19 September 2003
- What is Galileo? – European Space Agency informational article, updated 7 October 2003 (contains several links to related articles)
- GPS and Galileo: where are we headed? (PDF) – By Professor David Last, Univ. of Wales
- US, EU reach final accord in satellites row – AFP/EUbusiness Ltd, 21 June 2004
-  Galileo Industries Webpage
- Europe presses ahead on sat-navigation
- EU-US strike sat-navigation deal
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