Galileo positioning system

27 satellites in . Image: ESA
27 satellites in orbit. Image: ESA

The Galileo positioning system is a proposed satellite navigation system, to be built by the European union as an alternative to the military controlled US Global Positioning System and the Russian GLONASS. The system should be operational by 2008. It is not abbreviated to GPS. Use of the acronym "GPS", here and elsewhere, refers to the existing United States system.

This system is intended to provide:

  • Greater precision to all users than is currently available.
  • Improved coverage of satellite signals at higher latitudes, which northern countries such as Scandinavia will benefit from.
  • A global positioning system that can be relied on, even in times of war.


The first stage of the Galileo program was agreed upon officially on May 26, 2003 by the European Union and the European Space Agency. But system studies were conducted well before. In 1999 the 4 different concepts (from France, Germany, Italy and The United Kindom) for Galileo were compared and reduced to one concept by a joint team of engineers from all four countries. 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. 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 ESA, as a way had to be found to convince the Member States to reduce the funding.

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.

International involvement

In September 2003, China joined the Galileo project. China will invest 230 million (USD 296 million, GBP 160 million) in the project over the next few years (see external link, below).

In July 2004, Israel signed an agreement with the EU to become a partner in the Galileo project. [1] ( [2] (

There is speculation that other countries might join the Galileo project, including India, Brazil, Mexico, Chile, Japan, Russia, Ukraine, South Korea, Australia. [3] ( [4] (

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 independence from the United States and its GPS system. A strong motivator for seeking independence is that, though GPS is now widely used worldwide for civilian applications, it is a military system, with selective availability, that can be disabled in times of war. Civil infrastructure, including aeroplane navigation and landing, cannot rely solely upon GPS.

Galileo Satellite Test Beds 2A and 2B

ESA and GJU aim to launch one of the two satellites, GSTB-2A and GSTB-2B, by 6th of December 2005. GSTB-2A, built by Surrey Satellite Technology Ltd (SSTL), is basically a transmitter beacon, while GSTB-2B, built by Galileo Industries, has an evolved payload which includes two atomic clocks. In both cases the primary objective is achieving the ITU frequency-filing requirements that require using the allocated transmission frequencies by the set deadline date. GSTB-2B also has clock and MEO environment characterisation objectives, as well as Signal-In-Space and receiver experiments. GSTB-2B will contain a Rubidium atomic clock and the first (west European) Passive Hydrogen Maser atomic clock used in space, built in Switzerland and Italy, respectively. GSTB-2B uses the Alcatel Proteus spacecraft bus. The GSTB-2B Mission Control Centre is in Fucino (Italy).


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.

External links

de:Galileo (Satellitennavigation) nl:Galileo (navigatie) no:Galileo pt:Galileo (navegação por satélite) fi:Galileo fr:Galileo (système de positionnement)


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