The Eropean Satellite Navigation System "Galileo"
by: Erich Strasser
The Galileo positioning system is a proposed satellite navigation system, to be built by the European Union (EU) as an alternative to the US military-controlled Global Positioning System and the Russian GLONASS. The system should be operational by 2010, two years later than originally anticipated.The Galileo positioning system is not abbreviated to GPS; use of the acronym "GPS", here and elsewhere, refers to the existing United States system.
The Galileo System will comprise global, regional and local components. The global component is the core of the system, comprising the satellites and the required ground segment
The regional component of Galileo may comprise a number of External Region Integrity Systems (ERIS), implemented and operated by organisations, countries or groups of countries outside Europe to obtain integrity services independent of the Galileo System, in order, for example, to satisfy legal constraints relating to system guarantees. Local components may be deployed for enhancing the performance of Galileo locally. These will enable higher performance such as the delivery of navigation signal in areas where the satellite signals cannot be received. Value-added service providers will deploy local components.
The first stage of the Galileo program was agreed upon officially on May 26, 2003 by the European Union and the European Space Agency (ESA). But system studies were conducted well before. In 1999 the 4 different concepts (from France, Germany, Italy and The United Kingdom) 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 public GPS access 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.On March 20, 2003, the United States and three other countries began military operations in Iraq, further motivating the EU to develop a navigation system independent of US control.
http://www.galileo-navigation.netAbout The Author
Erich Strasser
Webmaster of
www.galileo-navigation.net[email protected]
