Galileo (satellite navigation)

This article is about the global navigation satellite system. For the probe to the planet Jupiter, see Galileo (spacecraft).

Galileo

Country/ies of originEuropean Union
Operator(s)EUSPA, ESA
TypeCivilian, commercial
StatusInitial services[1][2][3]
CoverageGlobal
Accuracy20 cm (public since 24 January 2023)
Constellation size
Nominal satellites30 (24 active + 6 spares)[4]
Current usable satellites25 usable (09/2024)[2]
First launch28 December 2005
Last launch17 September 2024
Total launches15
Orbital characteristics
Regime(s)3 × MEO planes
Orbital height23222 km
Orbital period10⁄17 sd (about 14 hours 4 minutes 45 seconds)
Revisit period10 sidereal days
Other details
Cost€10 billion[5] (initial constellation)
Websitegsc-europa.eu (European GNSS Service Centre)
Geodesy
Fundamentals
Concepts
Technologies
Standards (history)
NGVD 29 Sea Level Datum 1929
OSGB36 Ordnance Survey Great Britain 1936
SK-42 Systema Koordinat 1942 goda
ED50 European Datum 1950
SAD69 South American Datum 1969
GRS 80 Geodetic Reference System 1980
ISO 6709 Geographic point coord. 1983
NAD 83 North American Datum 1983
WGS 84 World Geodetic System 1984
NAVD 88 N. American Vertical Datum 1988
ETRS89 European Terrestrial Ref. Sys. 1989
GCJ-02 Chinese obfuscated datum 2002
Geo URI Internet link to a point 2010

Galileo is a global navigation satellite system (GNSS) created by the European Union through the European Space Agency (ESA) and operated by the European Union Agency for the Space Programme (EUSPA).[6] It is headquartered in Prague, Czechia,[7] with two ground operations centres in Oberpfaffenhofen, Germany (mostly responsible for the control of the satellites), and in Fucino, Italy, (mostly responsible for providing the navigation data).[8] The €10 billion project went live in 2016.[5][9][10] It is named after the Italian astronomer Galileo Galilei.

One of the aims of Galileo is to provide an independent high-precision positioning system so European political and military authorities do not have to rely on the US GPS, or the Russian GLONASS systems, which could be disabled or degraded by their operators at any time.[11] The use of basic (lower-precision) Galileo services is free and open to everyone. A fully encrypted higher-precision service is available for free to government-authorized users.[12][13] Galileo is also to provide a new global search and rescue (SAR) function as part of the MEOSAR system.

The first Galileo test satellite GIOVE-A was launched 28 December 2005, while the first satellite to be part of the operational system was launched on 21 October 2011. Galileo started offering Early Operational Capability (EOC) on 15 December 2016,[1] providing initial services with a weak signal.[14] In October 2018, four more Galileo satellites were brought online, increasing the number of active satellites to 18.[15] In November 2018, the FCC approved use of Galileo in the US.[16] As of September 2024, there are 25 launched satellites that operate in the constellation.[17][18][19] It is expected that the next generation of satellites will begin to become operational after 2026 to replace the first generation, which can then be used for backup capabilities.

The Galileo system has a greater accuracy than GPS, having an accuracy of less than 1 m when using broadcast ephemeris (GPS: 3 m)[20] and a signal-in-space ranging error (SISRE) of 1.6 cm (GPS: 2.3 cm) when using real-time corrections for satellite orbits and clocks.[21][22]

  1. ^ a b "Galileo begins serving the globe" (Press release). European Space Agency. 15 December 2016. Archived from the original on 2 August 2024. Retrieved 15 December 2016.
  2. ^ a b "Constellation Information | European GNSS Service Centre". www.gsc-europa.eu. Archived from the original on 31 December 2019. Retrieved 11 September 2024.
  3. ^ "NAGUs (Notice Advisory to Galileo Users) | European GNSS Service Centre". www.gsc-europa.eu. Retrieved 28 February 2020.
  4. ^ https://www.euspa.europa.eu/eu-space-programme/galileo/faqs/what-does-galileo-consist
  5. ^ a b "Brexit is breaking up Europe's €10 billion plan to launch a new constellation of satellites". Quartz. Retrieved 28 April 2018.
  6. ^ "On a Civil Global Navigation Satellite System (GNSS) between the European Community and its Member States and Ukraine" (PDF). Archived (PDF) from the original on 8 February 2015. Retrieved 12 January 2015.
  7. ^ "The opening ceremony of GSA Agency's headquarters was attended by VIPs in space activities and satellite navigation". czechspaceportal.cz (in Czech). 10 September 2012. Archived from the original on 2 April 2018. Retrieved 2 April 2018.
  8. ^ "Galileo: Europas Navigationssatellitennetz komplett ausgefallen - WELT".
  9. ^ "Galileo navigational system enters testing stage". Deutsche Welle. Retrieved 13 October 2012.
  10. ^ "Galileo Initial Services". gsa.europa.eu. 9 December 2016. Retrieved 25 September 2020.
  11. ^ "Why Europe needs Galileo". ESA. 12 April 2010. Retrieved 21 June 2014.
  12. ^ "Directions 2018: Galileo ascendant". GPS World. 8 December 2017. Retrieved 8 May 2021.
  13. ^ "EU Space Policy: Galileo". European Commission Defense Industry and Space. European Commission. Archived from the original on 2 January 2022.
  14. ^ "Galileo Future and Evolutions". European Space Agency. Retrieved 24 August 2021.
  15. ^ "Four more Galileo satellites brought online". Euspa.europa.eu. 26 October 2018.
  16. ^ "FCC approves use of Galileo in the US". Galileo. 19 November 2018.
  17. ^ "Constellation Information | European GNSS Service Centre". www.gsc-europa.eu. Retrieved 17 October 2019.
  18. ^ "Galileo Elliptical Auxiliary Satellites Removed from Service". Inside GNSS. 23 February 2021. Retrieved 17 December 2021.
  19. ^ Hadas, Tomasz; Kazmierski, Kamil; Sośnica, Krzysztof (7 August 2019). "Performance of Galileo-only dual-frequency absolute positioning using the fully serviceable Galileo constellation". GPS Solutions. 23 (4): 108. Bibcode:2019GPSS...23..108H. doi:10.1007/s10291-019-0900-9.
  20. ^ "After 13 years, Galileo satellite navigation complete at last". De Ingenieur (in Dutch).
  21. ^ Kazmierski, Kamil; Zajdel, Radoslaw; Sośnica, Krzysztof (2020). "Evolution of orbit and clock quality for real-time multi-GNSS solutions". GPS Solutions. 24 (111). Bibcode:2020GPSS...24..111K. doi:10.1007/s10291-020-01026-6.
  22. ^ Bury, Grzegorz; Sośnica, Krzysztof; Zajdel, Radosław; Strugarek, Dariusz (2020). "Toward the 1-cm Galileo orbits: challenges in modeling of perturbing forces". Journal of Geodesy. 94 (16): 16. Bibcode:2020JGeod..94...16B. doi:10.1007/s00190-020-01342-2.