Galileo is a global navigation satellite system (GNSS) developed by the European Union and operated entirely under civilian control. In operation since 2016, it offers a high-accuracy and independent solution specifically tailored to Europe’s positioning and timing needs. Unlike the U.S.'s GPS and Russia’s GLONASS, Galileo is designed with civilian users in mind, marking a key point of differentiation.

Today, over 3.5 billion devices worldwide benefit from Galileo signals. Thanks to its dual-frequency transmission, Galileo enables real-time positioning accuracy down to one meter. The system is also built to be interoperable with other GNSS constellations such as GPS and GLONASS, ensuring global coverage and compatibility.

System Structure and Technical Infrastructure

The Galileo satellite constellation consists of 24 operational satellites distributed across three orbital planes, along with spare satellites. These satellites orbit in Medium Earth Orbit (MEO) at an altitude of approximately 23,222 km. Although two satellites were placed in incorrect orbits, they are still utilized for search and rescue operations. This orbital configuration ensures strong signal accuracy even at high latitudes, including polar regions.

The ground infrastructure includes two main control centers—located in Fucino, Italy, and Oberpfaffenhofen, Germany—as well as a network of Galileo Sensor Stations (GSS). Supporting facilities include the Galileo Security Monitoring Centre (France and Spain), the European GNSS Service Centre (Spain), and the Galileo Reference Centre (Netherlands). Together, this infrastructure ensures the integrity and synchronization of Galileo’s timing and navigation services.

Provided Services and Application Domains

Galileo offers four core services:

• Open Service (OS): The basic service used in smartphones, vehicle navigation systems, and wearable devices.
• Search and Rescue (SAR): Detects emergency distress calls in under 10 minutes and confirms reception by notifying the sender that help is on the way.
• High Accuracy Service (HAS): Delivers precision up to 20 cm for applications such as autonomous vehicles and precision agriculture.
• Public Regulated Service (PRS): An encrypted and robust service reserved for authorized government users, including police, customs, and civil protection agencies, especially designed to function reliably in crises.

Additionally, successful tests have been conducted for OSNMA (Open Service Navigation Message Authentication), a feature that ensures GNSS data integrity and verifies that information received by the user is genuinely from Galileo. Application areas include smart agriculture, autonomous transportation systems, maritime operations, time-stamping for banking transactions, energy grid synchronization, and mobile communications. For instance, Galileo provides nanosecond-level timing accuracy for secure and efficient financial operations.

Future Vision and Advancements

Galileo’s second-generation satellites are being progressively deployed throughout the 2020s. These satellites incorporate advanced technologies such as electric propulsion, fully digital payloads, reprogrammable components, and more accurate atomic clocks. These features enable dynamic adaptation of the system based on evolving user demands. One of the most anticipated developments is the Emergency Warning Satellite Service (EWSS), scheduled to go operational in 2025. This service will deliver real-time alerts directly to the public during natural or man-made disasters, including hazard severity, duration, affected zones, and safety instructions. Designed to complement existing alert systems, EWSS aims to ensure communication continuity even in rural or network-congested areas.