Galileo (satellite navigation)
Galileo is a global navigation satellite system (GNSS) that went live in 2016, created by the European Union through the European Space Agency (ESA), operated by the European Union Agency for the Space Programme (EUSPA), headquartered in Prague, Czechia, with two ground operations centres in Fucino, Italy, and Oberpfaffenhofen, Germany. The €10 billion project is named after the Italian astronomer Galileo Galilei.
| Country/ies of origin | European Union |
|---|---|
| Operator(s) | EUSPA, ESA |
| Type | Civilian, commercial |
| Status | Initial services |
| Coverage | Global |
| Accuracy | 20 cm (public since 24 January 2023) |
| Constellation size | |
| Nominal satellites | 30 (24 active + 6 spares) |
| Current usable satellites | 23 usable, 1 not available, 4 not usable (09/2022) |
| First launch | 2011 |
| Total launches | 28 |
| Orbital characteristics | |
| Regime(s) | 3 × MEO planes |
| Orbital height | 23222 km |
| Orbital period | 10⁄17 sd or 14 hours and 5 minutes |
| Revisit period | 10 sidereal days |
| Other details | |
| Cost | €10 billion (initial constellation) |
| Website | gsc-europa.eu (European GNSS Service Centre) |
| Geodesy |
|---|
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. 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. 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, providing initial services with a weak signal. In October 2018, four more Galileo satellites were brought online, increasing the number of active satellites to 18. In November 2018, the FCC approved use of Galileo in the US. As of December 2023, there are 23 launched satellites that operate in the constellation, five are not available. It is expected that the next generation of satellites will begin to become operational after 2025 to replace older equipment, 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) 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.