Jump to content

Galileo (satellite navigation)

From Wikipedia, the free encyclopedia

This is an old revision of this page, as edited by Jiri Svoboda (talk | contribs) at 10:19, 10 June 2011 (October 2011 launch of first two FOC satellites announced by ESA). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.

Galileo logo

Galileo is a global navigation satellite system (GNSS) currently being built by the European Union (EU) and European Space Agency (ESA). The €5.3 billion project is named after the famous Italian astronomer Galileo Galilei. One of the political aims with Galileo is to provide a high-accuracy positioning system upon which European nations can rely independent from the Russian GLONASS and US GPS systems, which can be disabled for commercial users in times of war or conflict.[1] When in operation, it will use the two ground operations centres, one near Munich, Germany, and another in Fucino, Italy and will consist initially of 18 satellites by 2015. An additional €1.9 billion is planned to be spent bringing the system up to the full complement of 30 satellites (27 operational + 3 active spares).[2][3] The first experimental satellite, GIOVE-A, was launched in 2005 and was followed by a second test satellite, GIOVE-B, launched in 2008. The first four operational satellites for navigation will be launched in 2011 and once this In-Orbit Validation (IOV) phase has been completed, additional satellites will be launched. On 30 November 2007 the 27 EU transportation ministers involved reached an agreement that it should be operational by 2013,[4] but later press releases suggest it was delayed to 2014.[5]

The navigation system is intended to provide measurements down to the metre range as a free service including the height (altitude) above sea level, and better positioning services at high latitudes compared to GPS and GLONASS (though with recent upgrades to GPS similar accuracy levels are reached[citation needed]). As a further feature, Galileo will provide a global Search and Rescue (SAR) function. To do so, each satellite will be equipped with a transponder, which is able to transfer the distress signals from the user's transmitter to the Rescue Co-ordination Centre, which will then initiate the rescue operation. At the same time, the system will provide a signal to the user, informing them that their situation has been detected and that help is on the way. This latter feature is new and is considered a major upgrade compared to the existing GPS and GLONASS navigation systems, which do not provide feedback to the user.[6] The use of basic (low-accuracy) Galileo services will be free and open to everyone. The high-accuracy capabilities will be available for paying commercial users and for military use.[citation needed]

History

In 1999, the different concepts (from Germany, France, Italy and the United Kingdom) for Galileo were compared and reduced to one by a joint team of engineers from all four countries. The first stage of the Galileo programme was agreed upon officially on 26 May 2003 by the European Union and the European Space Agency. The system is intended primarily for civilian use, unlike the United States system, which the U.S. military runs and uses on a primary basis. The U.S. reserves the right to limit the signal strength or accuracy of GPS, or to shut down public GPS access completely (although it has never done the latter), so that only the U.S. military and its allies would be able to use it in time of conflict. Until 2000, the precision of the signal available to non-U.S.-military users was limited (due to a timing pulse distortion process known as selective availability). The European system will only be subject to shutdown for military purposes in extreme circumstances. It will be available at its full precision to both civil and military users.

The European Commission had some difficulty getting money for the project's next stage, after several allegedly "per annum" sales projection graphs for the project were exposed in November 2001 as "cumulative" projections (which for each year projected, necessarily included all previous years of sales). The attention that was brought to this multi-billion euro exponentially growing error in sales forecasts resulted in a general awareness in the Commission and elsewhere that the program did not have near the return on investment that had been presented to the investors and decision-makers up until that point.[7] Additionally, following the September 11, 2001 attacks, the United States Government wrote to the European Union opposing the project, arguing that it would end the ability of the United States to shut down satellite navigation in times of military operations. On 17 January 2002 a spokesman for the project stated that, as a result of U.S. pressure and economic difficulties, "Galileo is almost dead."[8] A few months later, however, the situation changed dramatically. Partially in reaction to the pressure exerted by the U.S. Government, European Union member states decided it was important to have a satellite-based positioning and timing infrastructure that the US could not easily turn off in times of political conflict.[9]

The European Union and the European Space Agency agreed in March 2002 to fund the project, pending a review in 2003 (which was finalised on 26 May 2003). The starting cost for the period ending in 2005 is estimated at €1.1 billion. The required satellites (the planned number is 30) will be launched throughout the period 2006–2010 and the system will be up and running and under civilian control from 2010. The final cost is estimated at €3 billion, including the infrastructure on Earth, which is to be constructed in the years 2006 and 2007. The plan was for private companies and investors to invest at least two-thirds of the cost of implementation, with the EU and ESA dividing the remaining cost. An encrypted higher-bandwidth Commercial Service with improved accuracy would be available at an extra cost, with the base Open Service freely available to anyone with a Galileo-compatible receiver. Costs for the project have run 50% over initial estimates.[2]

In June 2004, in a signed agreement with the United States, the European Union agreed to switch to a modulation known as BOC(1,1) (Binary Offset Carrier 1.1) allowing the coexistence of both GPS and Galileo, and the future combined use of both systems. The European Union also agreed to address the "mutual concerns related to the protection of allied and U.S. national security capabilities."[10]

Early 2007, the EU had yet to decide how to pay for the system and the project was said to be "in deep crisis" due to lack of more public funds.[11] German Transport Minister Wolfgang Tiefensee was particularly doubtful about the consortium's ability to end the infighting at a time when only one testbed satellite had been successfully launched.

Although a decision was yet to be reached, on Friday the 13th of July 2007[12] EU countries discussed cutting €548m ($755m, £370m) from the union's competitiveness budget for the following year and shifting some of that cash to other parts of the financing pot, a move that could meet part of the cost of the union's Galileo satellite navigation system. European Union research and development projects could be scrapped to overcome a funding shortfall.

In November 2007, it was agreed to reallocate funds from the EU's agriculture and administration budgets[13] and to soften the tendering process in order to invite more EU companies.[14]

In April 2008, the EU transport ministers approved the Galileo Implementation Regulation. This allowed the €3.4bn to be released from the EU's agriculture and administration budgets.[15] This will allow the issuing of contracts to start construction of the ground station and the satellites.

In June 2009, the European Court of Auditors published a report, pointing out governance issues, substantial delays and budget overruns that led to project stalling in 2007, leading to further delays and failures.[16]

In October 2009, the European Commission cut the number of satellites from 28 to 22, with plans to order the remaining six at a later time. It also announced that the first OS, PRS and SoL signal will be available in 2013 and the CS and SOL sometime later. Current budget for 2006-2013 period planned for €3.4 billion was also considered as insufficient.[17] The think tank Open Europe has estimated the total cost of Galileo from start to completion, and then running it over a 20 year period, at a staggering €22.2 billion — a cost which will be borne entirely by taxpayers. Under the original estimates (from 2000) this cost would have been €€7.7 billion, of which only €2.6 billion was to be borne by taxpayers and the rest by private investors.[18]

In November 2009, a ground station for Galileo was inaugurated near Kourou (French Guiana).[19]

The launch of the first four in-orbit validation (IOV) satellites is currently planned for the 2nd half of 2011, while the launch of full operational capability (FOC) satellites is planned to start in late 2012.

As of March 2010 it was verified that the budget for Galileo would only be available to provide the 4 IOV and 14 FOC satellites by 2014, with no funds currently committed to bring the constellation above this 60% capacity.[20] Paul Verhoef, the then current satellite navigation program manager at the European Commission indicated that this limited funding would have serious consequences commenting at one point "To give you an idea, that would mean that for three weeks in the year you will not have satellite navigation" in reference to the currently proposed 18 vehicle constellation.

In December 2010 EU ministers in Brussels have voted Prague (Czech Republic) as the headquarters of the Galileo project.[21]

In January 2011, infrastructure costs up to 2020 were estimated at €5.3 billion. In that same month, Wikileaks revealed the opinion of CEO of German satellite company OHB-System, Berry Smutny. He is quoted saying that Galileo "is a stupid idea that primarily serves French interests".[22]

International involvement

In September 2003, China joined the Galileo project. China was to invest €230 million (USD 302 million, GBP 155 million, CNY 2.34 billion) in the project over the following years.[23]

In July 2004, Israel signed an agreement with the EU to become a partner in the Galileo project.[24]

On 3 June 2005 the EU and Ukraine signed an agreement for Ukraine to join the project, as noted in a press release.[25]

As of November 2005, Morocco have also joined the programme.

On 12 January 2006, South Korea joined the programme.

In November 2006, China abandoned the programme and decided to develop an independent global navigation system: Beidou navigation system.[26]

On 30 November 2007, the 27 member states of the European Union unanimously agreed to move forward with the project, with plans for bases in Germany and Italy. Spain did not approve during the initial vote, but approved it later that day. This greatly improves the viability of the Galileo project: "The EU's executive had previously said that if agreement was not reached by January 2008, the long-troubled project would essentially be dead."[27]

On 3 April 2009, Norway too joined the programme pledging €68.9 million toward development costs and allowing its companies to bid for the construction contracts. Norway while not a member of the EU is a member of the ESA.[28]

Political implications of Galileo project

Tension with the United States

Letter from Paul Wolfowitz to the Ministers of the Member State of the European Union from December 2001 as part of the US-lobbying campaign against Galileo

Galileo is intended to be an EU GNSS civilian system that allows all users access to it. GPS is a US GNSS military system that provides location signals that have high accuracy to US military users, while also providing somewhat accurate location signals to others. The GPS had the capability to block the "civilian" signals while still being able to use the "military" signal (M-band). A primary motivation for the Galileo project was international concern that the US could deny others access to GPS during political disagreements.[9]

Since Galileo was designed to provide the highest possible accuracy (possibly even greater than GPS) to anyone, the US was concerned that an enemy could use Galileo signals in military strikes against the US (some weapons like missiles use GNSS systems for guidance). The frequency initially chosen for Galileo would have made it impossible for the US to block the Galileo signals without also interfering with their own GPS signals. The US did not want to lose their GNSS capability with GPS while denying enemies the use of GNSS. Some US officials became especially concerned when Chinese interest in Galileo was reported.[29]

Some US officials have threatened to shoot down Galileo satellites in the event of a major conflict in which Galileo was used in attacks against American forces.[30] The EU's stance is that Galileo is a neutral technology, available to all countries and everyone. At first, EU officials did not want to change their original plans for Galileo, but have since reached a compromise, that Galileo was to use a different frequency. This allowed the blocking/jamming of one GNSS system without affecting the other, giving the US a greater advantage in conflicts in which it has the electronic warfare upper hand.[31]

GPS and Galileo

One of the reasons given for developing Galileo as an independent system was that GPS is widely used worldwide for civilian applications, which until 2000 had Selective Availability (SA) enabled (and could be re-enabled). This could intentionally render the locations given via GPS inaccurate. Galileo's proponents argued that civil infrastructure, including aeroplane navigation and landing, should not rely solely upon GPS.

On May 1, 2000, SA was disabled by the then President of the United States Bill Clinton, and in late 2001, the entity managing the GPS confirmed that they never intend to enable selective availability again.[32] Though Selective Availability still exists, on 19 September 2007, the US Department of Defense announced that the new GPS satellites will not be capable of implementing Selective Availability.[33] This means the wave of Block IIF satellites launched in 2009 (and all subsequent GPS satellites) do not support SA. As old satellites are replaced in the GPS modernization program, SA will cease to exist. The modernization programme also contains standardized features that allow GPS III and Galileo systems to inter-operate, allowing a new receiver to utilise both systems to improve accuracy. By combining GPS and Galileo, it can create an even more accurate GNSS system.

Final system description

Galileo satellites

  • 30 in-orbit spacecraft (including 3 spares)
  • orbital altitude: 23,222 km (MEO)
  • 3 orbital planes, 56° inclination, ascending nodes separated by 120° longitude (9 operational satellites and one active spare per orbital plane)
  • satellite lifetime: >12 years
  • satellite mass: 675 kg
  • satellite body dimensions: 2.7 m x 1.2 m x 1.1 m
  • span of solar arrays: 18.7 m
  • power of solar arrays: 1,500 W (end of life)

Services

The Galileo system will have five main services:

  • Open Access Navigation: This will be 'free to air' and for use by the mass market; Simple timing and positioning down to 1 metre.
  • Commercial Navigation (Encrypted): High accuracy to the centimetre; Guaranteed service for which service providers will charge fees.
  • Safety Of Life Navigation: Open service; For applications where guaranteed accuracy is essential; Integrity messages will warn of errors.
  • Public Regulated Navigation (Encrypted): Continuous availability even in time of crisis; Government agencies will be main users.
  • Search And Rescue: System will pick up distress beacon locations; Feasible to send feedback, confirming help is on its way.

Other secondary services will also be available.

The concept

Each satellite will have two types of atomic clocks 4 in total (2 rubidium frequency standards and 2 passive hydrogen masers) - critical to any sat-nav system and a number of other components. These clocks will provide an accurate timing signal for a receiver to calculate the time that it takes the signal to reach the target. This information is used to calculate the position of the receiver by trilaterating the difference in received signals from multiple satellites.

For more information of the concept of global satellite navigation systems, see GNSS and GNSS positioning calculation.

Satellite system

Galileo satellite test beds: GIOVE

GIOVE-A was successfully launched 28 December 2005.

In 2004 the Galileo System Test Bed Version 1 (GSTB-V1) project validated the on-ground algorithms for Orbit Determination and Time Synchronisation (OD&TS). This project, led by ESA and European Satellite Navigation Industries, has provided industry with fundamental knowledge to develop the mission segment of the Galileo positioning system.[34]

A third satellite, GIOVE-A2, was originally planned to be built by SSTL for launch in the second half of 2008.[35] Construction of GIOVE-A2 was terminated due to the successful launch and in-orbit operation of GIOVE-B.

The GIOVE Mission[36][37] segment operated by European Satellite Navigation Industries is exploiting the GIOVE-A/B satellites to provide experimental results based on real data to be used for risk mitigation for the IOV satellites that will follow on from the testbeds. ESA organised the global network of ground stations to collect the measurements of GIOVE-A/B with the use of the GETR receivers for further systematic study. GETR receivers are supplied by Septentrio as well as the first Galileo navigation receivers to be used to test the functioning of the system at further stages of its deployment. Signal analysis of GIOVE-A/B data has confirmed successful operation of all the Galileo signals with the tracking performance as expected.

In-Orbit Validation (IOV) satellites

These testbed satellites will be followed by four IOV Galileo satellites that will be much closer to the final Galileo satellite design. The launch of the first pair of satellites is scheduled for the second half of 2011 [38]. Once this In-Orbit Validation (IOV) phase has been completed, the remaining satellites will be installed to reach the Full Operational Capability.

Full Operational Capability (FOC) satellites

On 7 January 2010, it was announced that the contract to build the first 14 FOC satellites was awarded to OHB System and Surrey Satellite Technology Limited (SSTL). Fourteen satellites will be built at a cost of 566M euros ($811M; £510M).[39] Arianespace will launch the satellites for a cost of 397M euros ($569M; £358M). The first two satellites are scheduled to launch on 20 October 2011 from Guiana Space Centre using the Soyuz launcher[40].

The European Commission announced also that the contract of 85 million euros for the System support covering industrial services required by ESA for integration and validation of Galileo System was awarded to Thales Alenia Space. Thales Alenia Space subcontract performances to Astrium Gmbh and security to Thales Communications.

Science projects using Galileo

In July 2006, an international consortium of universities and research institutions embarked on a study of potential scientific applications of the Galileo constellation. This project, dubbed GEO6, is a 360-degree study oriented to the scientific community in its broader sense, aiming to define and implement new applications of Galileo.

Among the various GNSS users identified by the Galileo Joint Undertaking, the GEO6 project addresses the Scientific User Community (UC).

The GEO6 project aims at fostering possible novel applications within the scientific UC of GNSS signals, and particularly of Galileo.

The AGILE project is an EU-funded project devoted to the study of the technical and commercial aspects of Location-based Services (LBS). It includes technical analysis of the benefits brought by Galileo (and EGNOS); also studying the hybridisation of Galileo with other positioning technologies (network-based, WLAN, etc.). Within these project, some pilot prototypes were implemented and demonstrated.

On the basis of the potential number of users, potential revenues for Galileo Operating Company or Concessionaire (GOC), international relevance, and level of innovation, a set of Priority Applications (PA) will be selected by the consortium and they will be developed within the time frame of the same Project.

These applications will help to increase and optimise the use of the EGNOS services as well as the opportunities offered by the Galileo Signal Test-Bed (GSTB-V2) and the Galileo (IOV) phase.

Coins

European Satellite Navigation commemorative coin

The European Satellite Navigation project was selected as the main motif of a very high value collectors' coin: the Austrian European Satellite Navigation commemorative coin, minted on 1 March 2006. The coin has a silver ring and niobium “pill”, colour gold-brown. In the reverse, the niobium portion depicts navigation satellites orbiting the Earth. The ring shows different modes of transport (an aeroplane, a car, a container ship, a train and a lorry) for which satellite navigation was developed.

See also

Notes and references

Notes

  1. ^ "Why Europe needs Galileo". ESA. 2010-04-12. Retrieved 2010-04-21.
  2. ^ a b Taverna, Michael A. Aviation Weekly http://www.aviationweek.com/aw/generic/story_channel.jsp?channel=space&id=news/awst/2011/01/24/AW_01_24_2011_p39-284139.xml. {{cite news}}: Missing or empty |title= (help)
  3. ^ "Galileo's navigation control hub opens in Fucino". ESA. 2010-12-20. Retrieved 2010-12-20.
  4. ^ "'Unanimous backing' for Galileo". BBC. 2007-11-30. Retrieved 2010-04-19.
  5. ^ "Commission awards major contracts to make Galileo operational early 2014". 2010-01-07. Retrieved 2010-04-19.
  6. ^ "What is Galileo?". ESA. 2010-04-11. Retrieved 2010-12-21.
  7. ^ Van Der Jagt, Culver "Galileo: The Declaration of European Independence" a presentation at the Royal Institute of Navigation November 7, 2001
  8. ^ Guardian.co.uk
  9. ^ a b Johnson, Chalmers (2007). Nemesis: The Last Days of the American Republic. Holt, p. 235.
  10. ^ US-EU Agreement on Galileo
  11. ^ EU: Galileo project in deep 'crisis', CNN
  12. ^ MSN.com
  13. ^ EU agrees 2008 budget to include Galileo financing — EUbusiness.com - business, legal and financial news and information from the European Union
  14. ^ "Galileo 'compromise' is emerging". BBC News. 23 November 2007. Retrieved 3 May 2010.
  15. ^ "Galileo legal process ticks over". BBC News. 7 April 2008. Retrieved 3 May 2010.
  16. ^ European Court of Auditors - Special Report on the management of the Galileo programme's development and validation phase
  17. ^ Aviation Week - Europe Cuts Galileo Sats Order
  18. ^ "The EU's Galileo satellite project could cost UK taxpayers £2.6 billion more than originally planned" (Press release). openeurope.org.uk. 17 October 2010. Retrieved 24 November 2010.
  19. ^ Inauguration of site of Galileo station at Kourou, official website of esa
  20. ^ Initial Galileo Validation Satellites Delayed
  21. ^ Prague To Host EU Satellite Navigation Agency - Radio Free Europe, 13 December 2010
  22. ^ http://www.aftenposten.no/spesial/wikileaksdokumenter/article3985655.ece
  23. ^ China joins EU's satellite network - BBC News, 19 September 2003
  24. ^ Press release
  25. ^ Press release
  26. ^ Marks, Paul. "China's satellite navigation plans threaten Galileo". NewScientist.com. Retrieved 2006-11-09.
  27. ^ "'Unanimous backing' for Galileo". BBC News. 30 November 2007. Retrieved 3 May 2010.
  28. ^ GPSdaily.com
  29. ^ "EU, U.S. split over Galileo M-code overlay". GPS World. FindArticles.com. December 2002. Retrieved 2008-12-09.
  30. ^ "US Could Shoot Down EU Satellites if Used by Foes in Wartime". AFP. October 24, 2004. Retrieved 2008-12-09.
  31. ^ Giegerich, Bastian (2005). "Satellite States - Transatlantic Conflict and the Galileo System". Paper presented at the annual meeting of the International Studies Association, Hilton Hawaiian Village, Honolulu, Hawaii, Mar 05, 2005. Unpublished Manuscript.
  32. ^ Selective Availability. Retrieved August 31, 2007.
  33. ^ "DoD Permanently Discontinues Procurement Of Global Positioning System Selective Availability". DefenseLink. 18 September 2007. Retrieved 2007-12-17.
  34. ^ Galileo System Test Bed Version 1 experimentation is now complete, ESA News release, 7 January 2005
  35. ^ GIOVE-A2 to secure the Galileo programme, ESA News release, 5 March 2007
  36. ^ GIOVE mission core infrastructure, ESA press release, 26 February 2007.
  37. ^ One year of Galileo signals; new website opens, ESA press release, 12 January 2007.
  38. ^ "Launch site ready for first Galileo launch", "European Commission: Enterprise & Industry Latest News", April 11, 2011, accessed May 3, 2011.
  39. ^ "EU awards Galileo satellite-navigation contracts". BBC News date= 7 January 2010. {{cite news}}: Missing pipe in: |newspaper= (help)
  40. ^ "Galileo: Europe prepares for October launch" (Press release). esa.int. 23 May 2011. Retrieved 10 June 2011.

References

Further reading

  • Psiaki, M. L., “Block Acquisition of weak GPS signals in a software receiver”, Proceedings of ION GPS 2001, the 14th International Technical Meeting of the Satellite Division of the Institute of Navigation, Salt Lake City, Utah, September 11–14, 2001, pp. 2838–2850.
  • Bandemer, B., Denks, H., Hornbostel, A., Konovaltsev, A., “Performance of acquisition methods for Galileo SW receivers”, European Journal of Navigation, Vol.4, No. 3, pp 17–9, July 2006
  • Van Der Jagt, Culver W. Galileo : The Declaration of European Independence : a dissertation (2002). CALL #JZ1254 .V36 2002, Description xxv, 850 p. : ill. ; 30 cm. + 1 CD-ROM
Wikimedia Commons has media related to Galileo (satellite navigation).

Official websites

Other

Press coverage

Retrieved from "https://en.wikipedia.org/w/index.php?title=Galileo_(satellite_navigation)&oldid=433533499"