Galileo positioning system: Wikis


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Galileo is a global navigation satellite system (GNSS) currently being built by the European Union (EU) and European Space Agency (ESA). The €3.4 billion project is an alternative and complementary to the U.S. Global Positioning System (GPS) and the Russian GLONASS. On 30 November 2007 the 27 EU transportation ministers involved reached an agreement that it should be operational by 2013[1], but later press releases suggest it was delayed to 2014.[2]

When in operation, it will have two ground operations centers, one near Munich, Germany, and another in Fucino, 130 km east of Rome, Italy.[3][citation needed] Since 18 May 2007, at the recommendation of Transport Commissioner Jacques Barrot, the EU took direct control of the Galileo project from the private sector group of eight companies called European Satellite Navigation Industries, which had abandoned this Galileo project in early 2007.

Galileo is intended to provide more precise measurements than available through GPS or GLONASS (Galileo will be accurate down to the metre range) including the height (altitude) above sea level, and better positioning services at high latitudes. The political aim is to provide an independent positioning system upon which European nations can rely even in times of war or political disagreement, since Russia or the USA could disable use of their national systems by others (through encryption).

Like the US GPS, use of basic (low-accuracy) Galileo services will be free and open to everyone. However, the high-accuracy capabilities will be restricted to military use and paying commercial users.

Named for the Italian astronomer Galileo Galilei, the positioning system is officially referred to as just Galileo. It is also sometimes colloquially described as the Galileo positioning system; however, since this abbreviates to GPS, the shorter astronomer's name is preferred to avoid confusion with Navstar GPS.

Contents

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 the GPS systems, 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.[4] 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 GPS 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."[5] 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 their own independent satellite-based positioning and timing infrastructure.[citation needed]

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.

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."[6]

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.[7] German Transport Minister Wolfgang Tiefensee, was particularly doubtful about the consortium's ability to end the infighting at a time when only one of the 30 planned satellites had been successfully launched.

Although a decision was yet to be reached, EU countries on Friday the 13th of July 2007[8] discussed cutting €548m ($755m, £370m) from the union's competitiveness budget for next year and shift 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[9] and to soften the tendering process in order to invite more EU companies.[10]

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.[11] This will allow the issuing of contracts to start construction of the ground station and the satellites.

In June 2009 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[12].

In October 2009 European Commission cut number of satellites to from 28 to 22 with plans to order remaining 6 at later time. It also announced that first PRS and SoL signal will be available in 2013 and remaining sometime later. Current budget for 2006-2013 period planned for €3.4 billion euros was also considered as insufficient[13].

In November 2009, a ground station for Galileo was inaugurated near Kourou (French Guiana). The first satellite launch is planned for the end of 2010[14].

International involvement

In September 2003, China joined the Galileo project. China will invest €230 million (USD 302 million, GBP 155 million, CNY 2.34 billion) in the project over the next few years.[15]

In July 2004, Israel signed an agreement with the EU to become a partner in the Galileo project.[16]

On 3 June 2005 the EU and Ukraine signed an agreement for Ukraine to join the project, as noted in a press release.[17]

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

On 12 January 2006, South Korea joined the programme.

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."[18]

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.[19]

Political implications of Galileo project

Tension with the United States

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). 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.[20]

Some US officials have threatened to potentially shoot down Galileo satellites in the event of a major conflict.[21] The EU's stance is that Galileo is a neutral technology, available to all countries and everyone. Originally, 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.[22]

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.[23] 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.[24] This means the next wave of Block IIF satellites launching in 2009 will not support SA. As old satellites are replaced in the GPS modernization programme, SA will cease to exist. The modernisation programme also contains standardised 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

  • 28 spacecraft
  • 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

There will be four different navigation services available:

  • The Open Service (OS) will be free for anyone to access. The OS signals will be broadcast in two bands, at 1164–1214 MHz and at 1563–1591 MHz. Receivers will achieve an accuracy of <4 m horizontally and <8 m vertically if they use both OS bands. Receivers that use only a single band will still achieve <15 m horizontally and <35 m vertically, comparable to what the civilian GPS C/A service provides today. It is expected that most future mass market receivers, such as automotive navigation systems, will process both the GPS C/A and the Galileo OS signals, for maximum coverage.
  • The encrypted Commercial Service (CS) will be available for a fee and will offer an accuracy of better than 1 m. The CS can also be complemented by ground stations to bring the accuracy down to less than 10 cm. This signal will be broadcast in three frequency bands, the two used for the OS signals, as well as at 1260–1300 MHz.
  • The encrypted Public Regulated Service (PRS) and Safety of Life Service (SoL) will both provide an accuracy comparable to the Open Service. Their main aim is robustness against jamming and the reliable detection of problems within 10 seconds. They will be targeted at security authorities (police, military, etc.) and safety-critical transport applications (air-traffic control, automated aircraft landing, etc.), respectively.

In addition, the Galileo satellites will be able to detect and report signals from Cospas-Sarsat search-and-rescue beacons in the 406.0–406.1 MHz band, which makes them a part of the Global Maritime Distress Safety System.

Validation satellites

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.[25]

  • The GIOVE-A2 satellite, to be built by SSTL, will be ready for launch in the second half of 2008, to ensure continuous reservation of Galileo frequency use with the ITU.[26]

The GIOVE Mission[27][28] 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.

IOV Galileo satellites

These testbed satellites will be followed by four In-Orbit Validation (IOV) Galileo satellites that will be much closer to the final Galileo positioning satellite design. The first launch is scheduled in November 2010 and the second for early in 2011. Once this In-Orbit Validation (IOV) phase has been completed, the remaining satellites will be installed to reach the Full Operational Capability (FOC).

Operational satellites

On 7 January 2010, it was announced that the contract to build the first 14 operational satellites was awarded to OHB System and Surrey Satellite Technology Limited (SSTL). Fourteen satellites will be built at a cost of 566m euro ($811m; £510m)[29]. The first two are expected to be ready in October 2012. Arianespace will launch the satellites for a cost of 397m euro ($569m; £358m).

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

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

  1. ^ BBC NEWS | Science/Nature | 'Unanimous backing' for Galileo
  2. ^ EUROPA Press Release | Commission awards major contracts to make Galileo operational early 2014
  3. ^ Physorg.com
  4. ^ Van Der Jagt, Culver "Galileo: The Declaration of European Independence" a presentation at the Royal Institute of Navigation November 7, 2001
  5. ^ Guardian.co.uk
  6. ^ US-EU Agreement on Galileo
  7. ^ EU: Galileo project in deep 'crisis', CNN
  8. ^ MSN.com
  9. ^ EU agrees 2008 budget to include Galileo financing — EUbusiness.com - business, legal and financial news and information from the European Union
  10. ^ BBC NEWS | Science/Nature | Galileo 'compromise' is emerging
  11. ^ BBC NEWS | Science/Nature | Galileo legal process ticks over
  12. ^ European Court of Auditors - Special Report on the management of the Galileo programme's development and validation phase
  13. ^ Aviation Week - Europe Cuts Galileo Sats Order
  14. ^ Inauguration of site of Galileo station at Kourou, official website of esa
  15. ^ China joins EU's satellite network - BBC News, 19 September 2003
  16. ^ Press release
  17. ^ Press release
  18. ^ BBC NEWS | Science/Nature | 'Unanimous backing' for Galileo
  19. ^ GPSdaily.com
  20. ^ "EU, U.S. split over Galileo M-code overlay". GPS World. FindArticles.com. December 2002. http://findarticles.com/p/articles/mi_m0BPW/is_12_13/ai_n27579865. Retrieved 2008-12-09. 
  21. ^ "US Could Shoot Down EU Satellites if Used by Foes in Wartime". AFP. October 24, 2004. http://www.spacedaily.com/news/milspace-04zc.html. Retrieved 2008-12-09. 
  22. ^ 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. http://www.allacademic.com//meta/p_mla_apa_research_citation/0/7/2/1/4/pages72145/p72145-1.php. 
  23. ^ Selective Availability. Retrieved August 31, 2007.
  24. ^ "DoD Permanently Discontinues Procurement Of Global Positioning System Selective Availability". DefenseLink. 18 September 2007. http://www.defenselink.mil/releases/release.aspx?releaseid=11335. Retrieved 2007-12-17. 
  25. ^ Galileo System Test Bed Version 1 experimentation is now complete, ESA News release, 7 January 2005
  26. ^ GIOVE-A2 to secure the Galileo programme, ESA News release, 5 March 2007
  27. ^ GIOVE mission core infrastructure, ESA press release, 26 February 2007.
  28. ^ One year of Galileo signals; new website opens, ESA press release, 12 January 2007.
  29. ^ [1], "EU awards Galileo satellite-navigation contracts", BBC News, 7 January 2010

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

External links

Official websites

Other

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