Galileo (satellite navigation system)

Lore & Background

The Galileo programme was agreed upon officially on 26 May 2003 by the European Union and the ESA. The system is intended primarily for civilian use, unlike the more military-focused systems of the US, Russia, and China. However, the European system could be subject to shutdown for military purposes in extreme circumstances such as an armed conflict. Italy and Germany led the development of the first generation, while France plays a more prominent role in the Galileo Second Generation (G2G).

Funding faced difficulties after sales projections were exposed as cumulative rather than per annum, leading to a general awareness that the programme was unlikely to yield the return on investment previously suggested. In January 2002, a spokesman stated that due to US pressure and economic difficulties, 'Galileo is almost dead.' However, EU member states later decided it was important to have a satellite-based positioning infrastructure that the US could not easily turn off in times of political conflict. The EU and ESA agreed in March 2002 to fund the project, pending a 2003 review. The starting cost for the period ending in 2005 was estimated at €1.1 billion, with final cost estimated at €3 billion. By early 2011, costs had run 50% over initial estimates.

Tension arose with the United States because Galileo was designed to provide the highest possible precision to anyone, and the frequency initially chosen would have made it impossible for the US to block Galileo signals without interfering with its own GPS. An anonymous EU official claimed US officials implied they might consider shooting down Galileo satellites in a major conflict. A compromise was reached for Galileo to use different frequencies, allowing blocking or jamming of either GNSS without affecting the other. In June 2004, the EU agreed to switch to a binary offset carrier modulation BOC(1,1), allowing coexistence of both systems.

Reader's Guide

Galileo's significance lies in its provision of an independent European GNSS, reducing reliance on US GPS and Russian GLONASS, which could be disabled or degraded by their operators. The system offers a free basic service open to everyone, and since 24 January 2023, a higher-precision service previously restricted to government-authorized users has also been made freely available. Galileo also provides a new global search and rescue (SAR) function as part of the MEOSAR system. Its horizontal accuracy is greater than GPS in certain locations, with less than 1 m using broadcast ephemeris (GPS: 3 m) and a signal-in-space ranging error of 1.6 cm (GPS: 2.3 cm) when using real-time corrections. The system began offering Early Operational Capability on 15 December 2016, providing initial services with a weak signal. As of September 2024, 25 launched satellites operate in the constellation. The next generation of satellites is expected to become operational after 2026, replacing the first generation which can then be used for backup. Most satellites were built by OHB in Bremen, Germany, with contribution from Surrey Satellite Technology in Guildford, United Kingdom. The FCC approved use of Galileo in the US in November 2018.