Europe’s Galileo between present and future

by Fulvia Croci

Galileo is the Global Navigation Satellite System (GNSS) wanted and financed by the European Union and developed by ESA, designed to send radio signals providing positioning, navigation and timing information.

The Galileo Public Regulated Service (Prs) became operational in 2013 to deliver positioning data for the development of sensitive applications primarily intended for use by EU Member State government authorised users. Galielo's capabilities have grown with the addition of the OpenService Navigation Message Authentication (OSNMA), a data authentication function in open GNSS signals, and the High Accuracy Service (HAS), which provides access to the information required to estimate an extremely accurate positioning solution. But Galileo is not standing still.

Europe’s Galileo system – comprising a 24-satellite constellation to date, with its Open Service can deliver real-time positioning accuracy down to the meter range. Its strength lies precisely in the fact that it was created to meet many needs through the provision of services designed for different users. It's versatile and covers a wide range of areas from telecommunications, transportation, environment, to maritime surveillance and the security of citizens and infrastructure.

The Public Regulated Service (PRS), whose experimentation phase dates back to 2013, is Galileo's longest-running service. PRS is a high-precision service designed to provide positioning data for the development of sensitive applications intended for use by government-authorised users such as law enforcement agencies. The PRS service is designed to be compatible with military GPS services allowing the deployment of receivers simultaneously using secure signals. This feature ensures improved performance particularly in case of limited sky visibility or in the presence of directional disturbances in military or civil environments.

Experimentation with Open Service Navigation Message Authentication (OSNMA) began in 2020. It is a data authentication function for the Galileo Open Service users. OSNMA provides receivers with the assurance that the received Galileo navigation message is coming from the system itself and has not been modified. This authentication function is useful for several fields such as aviation or maritime sectors that may not be able to function nominally in the event of a modified signal.

The latest addition to the constellation's services is the High Accuracy Service (HAS), which offers a new dimension of precision delivering horizontal accuracy down to 20 cm and vertical accuracy of 40 cm. Unveiled during the European Space Conference last January, the new service presents an additional layer of real-time positioning corrections that are relayed to compatible receivers through the Galileo satellite signal. The ESA and the European Union have announced that the service will be further enhanced with the launch of the latest satellites, to be followed by Galielo's second-generation (G2) satellites. Moreover, the European Space Agency and EUSPAthe European Space Agency that deploys the system and provides services for Galileo- will oversee key upgrades to the system. The EUSPA intends to implement HAS in areas of strategic importance such as high-precision agriculture, robotics, autonomous driving, and satellite formation flying.