Galileo – European Union's satellite navigation system

The Galileo Open Service (OS) is a worldwide basic positioning and time synchronisation service that is open to all and free of charge. The accuracy of the open positioning information has been verified to be around 1,5 metres, including within the Nordic countries. This is better than the accuracy of the GPS system, which generally varies between 2 and 5 meters. Galileo's time data is slightly more accurate than that of GPS. The orbital inclination of the Galileo satellites is greater than in GPS, which means the satellites are more visible in northern Europe, with users in Finland benefiting from this in the form of better-quality positioning services.

The satellites transmit the OS signal on two different carrier frequencies, which improves the system’s signal immunity to interference. Dual-frequency reception also improves positioning accuracy.

Basic services of the Galileo OS became available worldwide in 2016 when the Galileo Initial Operational Capability (IOC) phase started. Before the declaration and deployment of the Full Operational Capability (FOC) phase, the system will undergo operational validation and the necessary system updates.

The High Accuracy Service (HAS) is a special Galileo service that provides the user with positioning accuracy of around 20 cm. The satellites transmit the HAS signal on a third frequency that is separate from the Galileo OS, with the HAS supplementing the positioning information provided by the Open Service (OS). The Galileo HAS is an open-access and free-of-charge service, but its use requires a receiving device capable of reception on the frequency band used by the service and of processing the signal broadcast.

The Galileo HAS service is currently under development and is not yet available to end users.

The plan is to introduce the HAS service in two phases. In the Initial Operational Capability (IOC) phase, the service will undergo operational validation and the necessary system updates. In the IOC phase, the service will already be accessible by users. The IOC phase of the HAS is scheduled to commence during 2022. Deployment at Full Operational Capability (FOC) will take place once the functioning of the service has been finalised and validated. This is planned to happen by the end of 2023.

Galileo offers various levels of authentication services for its open positioning and timing services that allow users to ensure that the signals received come from the Galileo system. Galileo Open Service Navigation Message Authentication (OS-NMA) and the Commercial Authentication Service (CAS) are both based on encrypted satellite signals that allow the GNSS receiver to verify the integrity of navigation messages and to ensure they come from a trusted source. This prevents third parties from falsifying the signals or spoofing receiver systems.

OS-NMA and the CAS use different encryption key management systems. The CAS distributes the keys to users via a pre-authenticated route. This enables the real-time decryption of the satellite signal in the receiving device. The open OS-NMA service uses a private-public key pair, which reduces the security requirements of the key distribution channel but on the other hand it also creates a delay in the satellite signal authentication process. The reliability of OS-NMA is comparable to the reliability of certificates used by web browsers: users have to trust that a genuine certificate has been installed by a benevolent actor.

The plan is for the open authentication service OS-NMA to enter Initial Operational Capability (IOC) phase and open the service for end users during 2022. After this, the service will be validated, and system technology updated if necessary. The plan is to reach Full Operational Capability (FOC) by the end of 2023.

The schedule for the deployment of the commercial authentication service CAS is open for the time being.

The Galileo satellites are able to provide support to the international COSPAS-SARSAT emergency signal system. Galileo Support to Search and Rescue Service (SAR/Galileo) contains a unique Return Link Service (RLS) which provides an acknowledgement for the distress signal, ensuring the sender that SAR response has activated. The detection and location of distress signals has been determined to take place with-in 10 minutes from signal transmission. The Galileo SAR service requires the use of a special emergency beacon.

The SAR/Galileo RLS was declared fully operational on 21 January 2020. The service is provided free of charge.

Unfortunately, traditional satellite navigation services are relatively vulnerable to both deliberate jamming and spoofing as well as to unintentional atmospheric interference and distortion. The purpose of Galileo Public Regulated Service (PRS) it to provide electronically and functionally secured, continuous location and time data for the vital functions of the EU Member States in all circumstances – including crisis situations. The PRS is used by such authorities and critical infrastructure actors that require continuous and disruption-free positioning and timing services. These user groups include telecommunications companies, banks, critical transport and logistics actors, the energy sector, police, rescue services, defence forces, border guards and customs

The Galileo PRS service is scheduled to be operational within the EU in 2025. Finland aims to nationally adopt the PRS as soon as possible after that. The Finnish Transport and Communications Agency (Traficom) has been designated as the Competent PRS Authority (CPA) in Finland. The CPA is in charge of user authorisations, supervision of receivers and the industrial manufacture of PRS equipment and, in particular, controlling the provision of the encryption keys required for the service to PRS users.

Read more about PRS