The Galileo satellite system, developed and operated by the European Union, stands as a significant advancement in global navigation satellite systems (GNSS). This system offers worldwide coverage, delivering precise positioning and timing information. Galileo consists of 30 satellites, 24 of which are operational and 6 serve as active spares, all orbiting Earth at an altitude of approximately 23,222 kilometres. These satellites are distributed evenly across three circular Medium Earth Orbit (MEO) planes.
The Galileo system operates in four different services: Open Service, Commercial Service, Public Regulated Service, and Search and Rescue Service.The Open Service is available to anyone with a Galileo-enabled receiver and provides positioning and timing services. The Commercial Service offers enhanced performance to paying users. The Public Regulated Service is an encrypted, robust service for government-authorised users such as civil protection services, fire brigades, and the police. The Search and Rescue Service contributes to the international distress beacon locating system. Unlike other GNSS, Galileo is under civilian control, which provides a high level of service reliability and continuity not influenced by military requirements. The system is interoperable with GPS and GLONASS, the US and Russian global satellite navigation systems. Galileo's atomic clocks provide highly accurate timing information, which is crucial for many applications, including financial transactions and power grid management. The system's precision can reach up to one metre, which is significantly more accurate than non-military GPS signals.
