A satellite-based radio navigation system initiated by the European Union and European Space Administration (ESA). Using 24 satellites and six spares, Galileo was designed to interoperate with the U.S. GPS and Russian GLONASS systems. The first Galileo test satellite (GIOVE-A) was launched in late 2005, and the initial system went live in 2016. With 30 active satellites as of 2025, positioning accuracy is one meter (GPS is 20m; GLONASS is 60m). See
GNSS and
GPS.