FAQ

ºview of planet

System and programme

Services

GSC

Devices

What is Galileo?

Galileo is the European Union's Global Satellite Navigation System (GNSS). Like the other global systems, Galileo provides radio signals for position, navigation and timing purposes. When completed, Galileo will offer the following services: Open Service, Public Regulated Service, Search and Rescue Service, High Accuracy Service, and Commercial Authentication Service. Click here for more information.

What is Galileo?

Top

What does Galileo consist of?

The Galileo system is composed of three segments:

Space segment: The Galileo Space Segment consists of a constellation of satellites transmitting navigation signals providing user access to the Galileo services. The baseline constellation configuration is defined as 24/3/1 Walker constellation. 24 nominal Medium Earth Orbit satellites are arranged in 3 orbital planes.

Ground segment: The Galileo Ground Segment includes both the Ground Control Segment (GCS) and the Ground Mission Segment (GMS) and it encompasses the following infrastructures:
• Two Galileo Control Centres (GCC)
• A worldwide network of Galileo Sensor Stations (GSS).
• A worldwide network of Galileo Uplink Stations (ULS).
• A worldwide network of Telemetry, Tracking & Control stations (TTC stations).

User segment: Different GNSS receivers and devices, which receive the Galileo Signal In Space (SiS).

Click here for more information.

European GNSS Service Centre (GSC)

Top

Why does Europe need Galileo?

Space is big business. The space sector is worth between €46-54 billion to the EU economy and provides over 230,000 jobs in the EU. What’s more, the global GNSS market is expected to grow from 5.8 billion devices in 2017 to an estimated 8 billion by 2020, with 7.5 billion apps using GNSS. Thanks to this growth, the GNSS downstream market is expected to generate over EUR 70 billion in revenue annually, which more than doubles when revenue from added-value services is included.

With its own GNSS system in Galileo, Europe is at the forefront of these developments. The European research and development and industrial sectors are able to leverage Galileo’s increased accuracy in countless products and services, creating added value for the European economy and improving the lives of European citizens.

It is also important to remember that, unlike other global satellite navigation systems, Galileo is a civilian system – it was conceived with service provision to end users at its core. This is an important distinction, especially as our dependence on GNSS continues to increase.

Top

Who is involved in Galileo?

Galileo is a joint initiative of the European Commission, the European Union Agency for the Space Programme and the European Space Agency.

The Galileo programme is owned by the European Union (EU).

The European Commission has overall responsibility for the programme, managing and overseeing the implementation of all activities on behalf of the EU.

Galileo's design, deployment, evolutions of the system and the technical development of infrastructure are entrusted to the European Space Agency (ESA).

The Commission has delegated the operational management of the programme to EUSPA, which oversees how Galileo infrastructure is used and ensures that Galileo services are delivered as planned and without interruption.

Top

What is the socio-economic impact of Galileo?

The benefits of Galileo can be measured by their socio-economic impact on users, society and the environment.

Users will benefit from more reliable and accurate positioning, aiding their navigation, especially in cities and built-up areas. Features like the Galileo Search and Rescue service and integration into the eCall system will reduce emergency service response time in the case of distress or accidents.

Also, Galileo's accurate timing will help make synchronisation of banking and financial transactions more resilient as well as those used in telecommunication and energy distribution networks that power the World economy.

Use of satellite navigation has helped drive world economic growth, particularly in high-tech industries, and experts predict that the global satellite navigation market will itself grow by more than 8% up until 2019. The additional resiliency provided by Galileo as the third global system, after GPS and GLONASS, is expected to enable a range of new applications and services that will benefit from increased positioning reliability and further drive economic growth in Europe and beyond.

The European Union Agency for the Space Programme (EUSPA) has conducted additional assessments that show significant economic and environmental benefits from Galileo and GNSS use in the decade to come.

Who is using Galileo today?

Top

What is the added value of Galileo with respect to other GNSS?

Europe is the only region worldwide developing a global civil-based GNSS initiative. Galileo programme stands alone as the world’s unique option for GNSS under civilian control. This is an important differentiator with regard to other GNSS systems, especially relevant when considering that the world’s dependence on GNSS is continuously increasing.

With Galileo constellation available, there are more GNSS satellites usable, meaning more accurate and reliable positioning and timing synchronization that can be globally achieved by the end users. This is especially relevant in higher latitudes where Galileo offers better coverage than other GNSS systems.

In addition, Galileo offers other added value services devoted to improving the performances at user level. To be remarked, Galileo allows:
• Positioning accuracy down to decimetre level.
• Robust positioning through the authentication of the navigation data.
• Resistance to interference (jamming and spoofing) and high resilience.
• Introduction of a return link for Search and Rescue operations.

Galileo Search and Rescue (SAR)

Top

When will Galileo reach the Final Operational Capability (FOC)?

Galileo performance will gradually be improved and new services will be introduced as further spacecraft are launched.

Galileo Initial Services was the first step towards its Full Operational Capability, meanwhile Galileo has grown and is serving already 2 billion phones, over 15 million cars, as well as delivering crucial information for emergency services. The performance of Galileo has been gradually improving as additional satellites have been added to the constellation. Upon completion, users will benefit from its full first-class performance, reliability and coverage.

Top

Do I have to pay for Galileo services?

The Galileo Services are free of charge and once the system becomes fully operational the Open Service and Search and Rescue Service will continue to be provided on a free-of-charge basis. The future High Accuracy Service (HAS) will also be offered free of charge.

Commercial Authentication Service (CAS) may be offered on a commercial basis, but this has still to be defined.

Is Galileo free?

Top

Who operates the Galileo system?

While the European Commission is ultimately responsible for the Galileo programme, the European Union Agency for the Space Programme (EUSPA) is responsible for deploying the system and providing technical support for operational tasks, in addition to service provision and market development.

In this way, EUSPA serves as the link between the satellites in space and the end user.

Top

When will I be able to use Galileo?

If you have a Galileo-enabled device, then you are already benefitting from Galileo’s added accuracy. Since Initial Services were launched in 2016, users around the world with Galileo enabled devices are being guided with positioning, navigation and timing information provided by Galileo.

Click here to find out if your device is Galileo-enabled.

Top

How many satellites will Galileo have?

Once the Galileo constellation reaches Full Operational Capability (FOC) it will consist of 30 satellites. The constellation will contain 24 operational satellites and auxiliary satellites not part of the baseline constellation. From most locations, six to eight satellites will always be visible, allowing positions and timing to be determined very accurately to within a few centimetres. Interoperability with other GNSS increases the reliability of Galileo services.

The next launches are planned from late 2021 onwards. In a first phase, this will re-enforce the constellation with the deployment of auxiliary satellites. After this, subsequent launches will be used for constellation replenishment purposes.

Top

What is multi-constellation capacity?

Galileo is interoperable with other Global Navigation Satellite Systems (GNSS) such as GPS, Russia’s GLONASS and China’s BeiDou. Receivers with multi-constellation capacity are able to combine signals from different constellations to provide greater positioning accuracy.

To further increase the level of Galileo integration, EUSPA works directly with chipset and receiver manufacturers through technology workshops, sharing Galileo updates, co-marketing efforts, and dedicated funding for receiver development projects and studies.

To learn more about multi-constellation, watch this video:

 

To find out if your receiver is Galileo-enabled, click here

How is Galileo performing?

Galileo’s performance has been excellent! Since the launch of Initial Services, the measured Galileo Open Service and Search and Rescue Service performance figures have comfortably exceeded the Minimum Performance Level thresholds set down in their respective Service Definition Documents.

To keep you up to date on Galileo’s performance, the European GNSS Service Centre (GSC) issues quarterly reports on Galileo OS and SAR performance, these can be found on the GSC website.

Where can I find official Galileo programme documentation?

All the official programme documentation related to Galileo is published in the Programme reference documentation section on the GSC website. All the documents published in this section should be used as the reference arranged/listed by service (i.e Open Service, High Accuracy Service...)

Top

Which are the expected performances of Galileo once fully deployed?

Expected performances of Galileo once the Full Operational Capability is reached, can be found in Annex D of the Open Service-Service Definition Document (OS SDD). In this section, the performance evolution is shown including Full Operational Capability with 24 satellites.

Top

Is Galileo compatible with the American GPS? and with other GNSS?

Galileo is fully interoperable with GPS, and their combined use will bring many benefits to the end user. Galileo satellites will offer more usable satellites, meaning more accurate and reliable positioning and timing synchronization for end users. Navigation in cities or in complex environments, where satellite signals can often be blocked by buildings, tunnels or cut-offs, will be particularly benefitted from the higher number of satellites in view.

Galileo's accurate timing capability will also contribute to enabling more robust, reliable, efficient and resilient synchronisation for critical user’s domains as banking and financial transactions, telecommunication and energy distribution networks.

Galileo is designed to be fully interoperable with the rest of the GNSS constellations.

Is Galileo the same as GPS?

Top

Can you use satellite navigation indoors?

When used in combination with other Global Navigation Satellite Systems (GNSS), Galileo significantly improves accuracy in challenging environments, including urban canyons and indoors. What’s more, in combination with other networks, such as 5G for example, Galileo provides the accuracy, ubiquity and security needed to support seamless indoor-outdoor navigation solutions.

Top

Who can I contact for more information about Galileo and its services?

The European GNSS Service Centre (GSC) is available to help all Galileo users. The GSC Helpdesk can be reached at https://www.gsc-europa.eu/helpdesk

Top

What is the Galileo Open Service?

The Galileo Open Service is a free mass market service for positioning, navigation and timing that can be used by Galileo enabled chipsets in smartphones or car navigation systems, for example.

Top

What is the Galileo Open Service Navigation Message Authentication?

Galileo Open Service Navigation Message Authentication (OSNMA) is a free authentication service, available worldwide to allow users to verify whether the navigation message is received by a genuine Galileo satellite. Authentication information is provided through the E1-B component.

Top

Why do we need Galileo OSNMA?

Spoofing attacks use false GNSS signals to trick GNSS receivers into false positioning and timing solutions, without the user noticing it.

Spoofing is a sophisticated form of interfering and falsifying satellite navigation signals (GNSS). During a spoofing attack, a ‘’spoofer’’ uses a radio transmitter to generate fake GNSS signals and can fool a smartphone into showing its current location in the middle of the ocean while the smartphone user is climbing a mountain.

GNSS signal falsification can have serious impacts on applications and market sectors that rely on precise navigation such as aviation, maritime or drones. For instance, erroneous data of a vessel’s position, speed and direction poses real threats to its own operations but also to surrounding ships, especially those carrying dangerous goods.

In recent years, spoofing attacks are increasing in number due to the availability of low-cost hardware and software able to generate GNSS-like signals.

OSNMA will allow authenticating the navigation data by means of a “digital signature”. However, it should be kept in mind that authentication does not prevent the occurrence of all kinds of spoofing, and does not protect against jamming. Nonetheless, this added layer of protection proposes to be one step ahead of evolving technological trends by amplifying the system’s overall robustness and resilience.

Galileo OSNMA FAQs

Which signals does Galileo OSNMA support?

The Galileo OSNMA is integrated in previously reserved fields of the Galileo I/NAV navigation message transmitted in the E1-B Galileo Open Service signal, and is valid for Galileo E1-B and E5-B dual and single frequency users.

Galileo OSNMA FAQs

How does Galileo OSNMA authenticate the data?

Galileo OSNMA concept relies on two main principles:

  1. Optimal transmission through Galileo satellites by adaptation of an existing standard lightweight broad­cast authentication protocol named TESLA (Timed-Efficient Stream Loss-Tolerant Authentication).
  2. Possibility to authenticate satellites that do not transmit OSNMA data with the data retrieved from satellites transmitting OSNMA, referred to as cross-authentication.

Galileo OSNMA FAQs

Why Galileo OSNMA does not use standard digital signatures as the primary authentication means?

Galileo OSNMA uses an adaptation of TESLA as the primary authentication means, instead of digital signatures, because it offers a better user performance: As the Galileo data typically authenticated is a few hundred of bits, using standard digital signatures would require more bits for the signature than the bits of information to authenticate. In contrast, OSNMA is a lightweight protocol that permits to use much less bits per authentication.

It is also better suited for cross-authentication. In exchange for that, it requires a loose time synchronization source. However, this loose time is necessary anyway for future spreading code-based authentication schemes like Galileo CAS, which will add even more robustness.

Galileo OSNMA FAQs

What do we need to use Galileo OSNMA?

Galileo OS receivers will require an additional firmware/software to:

  1. Retrieve the OSNMA dedicated fields in the navigation message.
  2. Process these data to confirm whether the data is authentic.
  3. Implement a time synchronization requirement versus Galileo System Time (GST) from below 15 seconds to a few minutes, depending on the operating mode, to process OSNMA.
  4. Maintain integrity of stored OSNMA cryptographic material (no confidentiality applies).

In addition, the receiver will need the public key, which can be updated when necessary through an over-the-air rekeying (OTAR) mechanism.

Galileo OSNMA FAQs

How do we use Galileo OSNMA Service?

Once the Galileo OS receiver is enabled with the required additional capabilities, the receiver will receive the navigation data and the corresponding OSNMA data (tag, TESLA chain key and TESLA root key). All this information together with the Public Keys is used and needed to authenticate the navigation message. If the result of the process is successful the user shall consider the navigation data as authentic.

The authentication process, including receiver requirements needed to implement OSNMA, is described in the Galileo Open Service Navigation Message Authentication (OSNMA) Receiver Guidelines For The Test Phase (link)

Galileo OSNMA FAQs

How does the authentication process work?

The OSNMA-enabled receiver receives the navigation data and the corresponding OSNMA data (tag, TESLA chain key and TESLA root key). The tag authenticates the navigation data transmitted before the tag and is received before its associated TESLA chain key. The receiver authenticates the TESLA chain key with the TESLA root key or with a previously authenticated key from the TESLA chain. The TESLA root key is authenticated by means of its digital signature using a Public Key that shall be available to the receiver. Finally, the receiver re-generates locally the tag with the verified TESLA chain key and the navigation data, and checks whether it matches with the received tag.

To ensure the security of the TESLA protocol and guarantee the authenticity of the data, the receiver must ensure it has received the navigation data and associated tag before the corresponding TESLA chain key is disclosed by the system. This implies that the receiver must be synchronised with a given accuracy with the Galileo System Time (GST) before receiving and processing OSNMA information. The time synchronisation requirement TL is set to 30 sec [TBC]. If the receiver verifies this condition, all tags for all authentication types can be used.

If the condition is not verified, slow MACs, i.e. messages whose associated TESLA chain key is transmitted with an extra delay, may be exploited. A receiver synchronised to GST with an accuracy better than TL + 300 sec, can process slow MAC with a 10 sub-frame delay (ADKD12).

In case none of the above conditions are met, the OSNMA protocol shall not be used.

The authentication process is described in the Galileo Open Service Navigation Message Authentication (OSNMA) Info Note (link). Further details are provided in the OSNMA ICD (link) and receiver guidelines (link).

Galileo OSNMA FAQs

How do we obtain the OSNMA Public Key?

he receiver must be provided with the Public Key to be able to authenticate the OSNMA data received from the SiS. The Public Key is available at the GSC Website under the GSC Products tab for those users subscribed to the Galileo OSNMA Public Observation Campaign (link). There the user can find the applicable OSNMA key material and related information: Message ID, Public Key ID, Public Key Point, Public Key Curve and the Public Key (.pem and .xml format together with their associated md5 checksum file).

In the future, the OSNMA service will also provide the capability to retrieve the Public Key from the SiS as explained in the next FAQ.

Galileo OSNMA FAQs

How do we install the updated Public Key on our receiver?

Installing and storing the verified Public Key in the user receiver is also known as “receiver initialisation” and consists in installing and storing in the receiver the cryptographic material required to access OSNMA. This is a one-off operation, requiring a connection to the GSC that will supply the necessary material. It is anticipated that this operation will only be performed by the receiver manufacturers and advanced users such as application developers, but will remain invisible to “standard” end users.

On the other hand, updating the Public Key may happen several times in the receiver lifetime for example, when Public Keys have been revoked, expired, or otherwise regenerated.  There are two methods to perform the reinstallation to the user receiver:

1. Through Public Key Renewal transmitted as part of the SiS authentication data (DSM-PKR message). This will be the nominal procedure, ensuring no required intervention and no service interruption for end users. In addition to this procedure, it is planned to broadcast the active Public Key with a low frequency, even when it is not renewed or revoked, to support users that missed the previous Public Key update. This process is not available during the OSNMA Public Observation phase, but it will be during the OSNMA operational provision. In order to verify the Public Keys transmitted in the SiS the user shall be in the possession of the Merkle tree root, that is also provided in the OSNMA server in GSC.

2. By accessing the OSNMA server in GSC, which will keep the history of the Public Keys status (this method is expected to be used by receiver manufacturers or advanced users, e.g. for preparation of firmware updates).

For further details, refer to  sections 3.2 and 5.1 in the Receiver Guidelines For The Test Phase (link).

Galileo OSNMA FAQs

What applications do Galileo OSNMA enable?

In general, this service is particularly useful for applications which require certain verification of the navigation data. A wide range of target applications where OSNMA is particularly useful are described in the Galileo Open Service Authentication (OSNMA) Info Note (link).

Galileo OSNMA FAQs

Which are the benefits of using Galileo OSNMA?

When using Galileo OSNMA Service, the user can be sure that the data received in the GNSS receiver come from a Galileo satellite and not from any other source, for example a malicious spoofer, or a testbed broadcasting Galileo-like signals by mistake. Thanks to Galileo OSNMA, users will be able to calculate positioning and timing with authenticated data with performance equal to the one obtained with the Galileo Open Service (OS). In addition to data authentication, Galileo OSNMA adds unpredictability to the Galileo signal, making it more difficult to replay.

Galileo OSNMA FAQs

Which are the differences between the Galileo OSNMA service and the future Galileo Commercial Authentication Service (CAS)?

Galileo OSNMA free service consists of ensuring the data authenticity of the navigation data of the Open Service (OS). Authentication information is provided through the E1-B component.

OSNMA will be complemented by the Commercial Authentication Service (CAS), which will offer spreading code authentication in the E6 frequency band.

Both OSNMA and CAS services offer global geographical coverage, and they are complementary to PRS (Public Regulated Service) which also provides authentication but only for government-authorized users.

Galileo OSNMA FAQs

Is Galileo OSNMA related to Integrity?

Authentication and GNSS integrity concepts are commonly confused, and this may lead to an erroneous understanding.

Galileo OSNMA provides data origin authentication, which means that the data is originated in the Galileo system, and is therefore “authentic”. Authentication is one application of cryptography, together with confidentiality, data integrity, and non-repudiation.

Data integrity assures that the transmitted information is correct and therefore has not been altered. Galileo provides data integrity by means of a “checksum” in the navigation message. As Galileo OSNMA ensures the origin of the data, and the Galileo navigation message ensures correctness of the received data, Galileo OSNMA users can ensure that the data received is the data transmitted by the system.

The concept of GNSS integrity is broader. It is a measure of the trust which can be placed in the correctness of the information supplied by the total system, including the corrections of the satellite errors, sometimes also signal propagation errors, and the boundaries of these errors. GNSS integrity also includes the ability of a system to provide timely and valid warnings to the user (alerts), when the errors exceed certain bounds.

GNSS integrity is a concept initially developed by the aviation community and has typically not focused on spoofing threats, but nowadays this is changing and GNSS authentication is being considered as a protection mechanism to maintain GNSS integrity not only against satellite or propagation errors, but also even against spoofing signals.

Galileo OSNMA FAQs

What if we do not need Galileo OSNMA?

Using previously reserved fields of the I/NAV message, OSNMA does not introduce any overlay to the system, thus the OS navigation performance remains untouched. Furthermore, this design ensures full backward compatibility, and standard OS receivers can continue ignoring the OSNMA dedicated fields of I/NAV and keep functioning with the same performance level. Only OSNMA ready receivers will decode these fields and be able to authenticate Galileo navigation data.

Galileo OSNMA FAQs

Is there any receiver enabled with OSNMA capabilities?

EUSPA has funded the development of receivers integrating the OSNMA algorithm. A list of such products, that may not be fully aligned to the latest OSNMA specification but which can still be considered as a (partial) baseline for testing purposes, is provided under Annex I to the OSNMA Info Note (link).

Galileo OSNMA FAQs

Where can we find out more about Galileo OSNMA?

Galileo OSNMA information is available on the GSC website (link to Info Note) and for specific questions, please contact GSC user helpdesk.

Galileo OSNMA FAQs

What is the Galileo Public Regulated Service?

The Public Regulated Service is for government authorised users, such as civil protection, fire brigades, customs officers and the police. It is particularly robust and fully encrypted to provide service continuity in national emergencies or crisis situations, such as terrorist attacks. Click here for more information

Top

What is the Galileo High Accuracy Service?

The Galileo High Accuracy Service (HAS) is a free high-accuracy positioning service for applications requiring higher accuracy than that offered by the Galileo Open Service.


The Galileo HAS provides precise corrections (orbit, clock, biases) transmitted in the Galileo E6 signal (E6-B, data component) from a subset of the Galileo satellites as well as via internet, allowing the user to achieve improved positioning performance.


The precise corrections provided by the HAS allow users to reduce the error associated with the orbit and clocks provided through the Galileo Open Service broadcast navigation messages and the GPS Standard Positioning Service navigation data. These corrections, together with the biases provided by the service and when processed by an appropriate algorithm, enable the computation of a High Accuracy PVT solution in real-time.


The Galileo HAS Initial Service provides the HAS Service Level 1 (described below) with reduced coverage and performance with respect to the Full Service objectives as enabled by the current Galileo infrastructure (e.g. Galileo Sensor Stations – GSS – network). With respect to the products expected as part of the HAS Full Service SL1 (see below), it is to be noted that phase biases are not yet provided.


In the future, the Galileo HAS Full Service will provide two different service levels:

  • Service Level 1 (SL1):
    • Service area:  global coverage.
    • Products (correction types): orbits and clocks corrections and code and phase biases.
    • Delivery channels: HAS Signal-In-Space (SIS) and HAS Internet Data Distribution Interface (IDD).
    • Accuracy target (95%): 20cm (horizontal) / 40cm (vertical).
    • Availability target: 99%.
    • Convergence time target: 300 seconds.
  • Service Level 2 (SL2):
    • Service area:  regional coverage (the European Coverage Area – ECA).
    • Products (correction types): SL1 products and atmospheric corrections.
    • Delivery channels: HAS SIS and IDD.
    • Accuracy target (95%): 20cm (horizontal) / 40cm (vertical).
    • Availability target: 99%.
    • Convergence time target: 100 seconds.

Top

What applications does the Galileo HAS enable?

The target markets identified for Galileo HAS include: geomatics, agriculture, aviation, road, consumer solutions, rail, maritime, inland waterways and space applications.

Galileo High Accuracy Service FAQs

What products does Galileo HAS provide?

The Galileo HAS Initial Service is based on the provision of the following information required to estimate an accurate positioning solution using a Precise Point Positioning Algorithm, mainly:

  • Satellite orbit corrections to the broadcast ephemeris;
  • Satellite clock corrections to the broadcast ephemeris;
  • Satellite code biases.

Additional information may be provided in the future as part of the HAS service evolutions towards the HAS Full Operational capability.

Galileo High Accuracy Service FAQs

How does the Galileo HAS improve user accuracy?

The Galileo HAS real-time orbit and clock corrections, and signal biases allow reducing GNSS errors using Precise Point Positioning (PPP) techniques.

Galileo High Accuracy Service FAQs

Which signals does the Galileo HAS support?

The HAS corrections are applicable to the following Galileo and GPS navigation messages and signals:

  • Galileo I/NAV navigation message and Galileo E1/E5b/E5a/E6 signals;
  • GPS LNAV navigation message and GPS L1/L2C signals.

Future service evolutions will correct additional signals, as Galileo E5 AltBOC and GPS L5.

Galileo High Accuracy Service FAQs

How does the Galileo HAS deliver the corrections?

HAS corrections are transmitted in the Galileo E6 signal (E6-B, data component) from a subset of the Galileo satellites as well as via Internet.

Galileo High Accuracy Service FAQs

Where can I find the Galileo codes over E6-B defined?

The Galileo E6-B codes are described here.

Galileo High Accuracy Service FAQs

What do I need to use the Galileo HAS?

You need a compatible Galileo-enabled receiver capable of receiving, decoding and properly applying (refer to the corresponding interface control documents) the HAS corrections from the Signal-In-Space (SIS) or the Internet Data Distribution (IDD) interface. Additionally, in order to compute a HAS positioning solution, an appropriate PPP user algorithm is required.

Galileo High Accuracy Service FAQs

Where can I find the specifications, structure and contents of HAS E6-B signal?

Galileo HAS ICD was published in May 2022.

Galileo High Accuracy Service FAQs

Where can I use the Galileo HAS?

The HAS service area is defined in the HAS Service Definition Document (SDD). The use of HAS outside the defined service is possible although the observed performance may differ with respect to the one described in the HAS SDD.

Galileo High Accuracy Service FAQs

What are the phases planned for Galileo HAS implementation?

The implementation of the Galileo HAS is following a staggered approach based on the three phases. Phase 0 for Testing and Experimentation, Phase 1 – Initial Service and Phase 2- Full Service for full SL1 and SL2 provision.


The Phase 0 activities were conducted in 2021 and the first half of 2022. Following their completion, Galileo engaged in HAS Initial Service validation activities which lead to the HAS Initial Service declaration as of 24th of January 2023. Hence, the Phase 1 of the HAS implementation is currently ongoing.


Future evolutions of the service will progressively improve the performance currently delivered by the HAS Initial Service towards the achievement of the HAS Full service objectives (Phase 2).

Galileo High Accuracy Service FAQs

What is the typical Galileo HAS positioning accuracy?

The currently supported typical positioning performance is described in the HAS Service Definition Document. In its full operational capability, Galileo HAS will support 20cm and 40cm (percentile 95) horizontally and vertically respectively.

Galileo High Accuracy Service FAQs

What will be the typical Galileo HAS convergence time?

In its Full Operational capability, the HAS convergence time will be less than 300 seconds for SL1 and less than 100 seconds for SL2.

Galileo High Accuracy Service FAQs

What is the typical Galileo HAS availability?

The currently supported availability of corrections is described in the HAS Service Definition Document (SDD), which also describes the typical availability of positioning.

The HAS Full service will support, both for SL1 and SL2, a service availability above 99%.

Galileo High Accuracy Service FAQs

How can I find out more about Galileo HAS?

Galileo HAS documentation is available in the GSC website. For specific questions, please contact GSC user helpdesk.

Galileo High Accuracy Service FAQs

What is the Galileo Authentication concept?

In Galileo, authentication will be offered in two ways:


• Open Service Navigation Message Authentication (OSNMA) that will make use of enhanced modulations (BOC variants) and encryption/authentication techniques to provide robustness against jamming and spoofing. As per the OS-NMA, it will provide users with a mean to validate that the received Navigation Message was generated by the Galileo Ground Segment.


• Commercial Authentication service (CAS) is understood as the ability to provide a level of guarantee to users regarding the use of signals and data from actual Galileo satellites and not from any other source. This capacity will increase the degree of trust on the services based on Galileo positioning and prevent spoofing of Galileo signals, which may lead to committing fraud. The purpose of this service is to satisfy the demand of GNSS users and applications of a trusted navigation solution provided by GNSS systems.

Top

What is the Galileo Search and Rescue service?

The Galileo Search and Rescue (SAR) service is Europe's contribution to an international emergency beacon locating system called "Cospas-Sarsat". Galileo is the first satellite constellation to offer global SAR capability and significantly reduces the time needed to accurately locate a distress beacon. Galileo SAR also contains a unique return link that lets users know that their distress signal has been received and that help is on the way. Click here for more information.

Galileo Search and Rescue (SAR)

Top

What are the Galileo Initial Services?

Launched in December 2016, Galileo Initial Services are the first step towards full operational capability, marking the transition from deployment and testing to operations. This means that all mass-market devices containing a Galileo-enabled chipset, such as smartphones and vehicle navigation devices, are able to use Galileo signals for positioning, navigation and timing.

The Initial Services offered by Galileo are Open Service, the Public Regulated Service (PRS) and the Search and Rescue Service (SAR). Click here for more information.

With the Declaration of Galileo Initial Services, the European Union announced that the Galileo satellites and ground infrastructure are ready for use. The conditions under which the Galileo Initial Services are being delivered, including their expected performance (accuracy, etc.) and availability, are published on the Galileo Open Service-Service Definition Document (OS SDD). Galileo Initial Services will evolve in accordance with the infrastructure deployment until the Full Operational Capability (FOC) is achieved. As a consequence, specific releases of the Service Definition Documents (OS SDD) will be issued to properly take into account such evolutions in future service declaration milestones.

Top

When do you expect all Galileo services to be available?

All of Galileo’s services will be available once the satellite constellation and ground infrastructure are completed, which is expected to happen by 2020. This will allow the full Galileo performance to be achieved and with maximum availability.

Top

What is the European GNSS Service Centre (GSC)?

The European GNSS Service Centre (GSC) is set to be an integral part of the European GNSS infrastructure and provides the single interface between the Galileo system and the users of the Galileo Open Service (OS), High Accuracy Service (HAS) and Commercial Authentication Service (GSC).

The GSC is conceived as a centre of expertise, knowledge sharing, custom performance assessment, information dissemination and support to the provision of value-added services enabled by Galileo.

Top

How can I contact and get support from GSC?

To get support from GNSS Service Centre you will need to register in the GSC website. Afterwards, any question or doubt can be raised using the Galileo Help Desk Contact Form.

Top

Which kind of services can I obtain from GSC?

The functionality and services currently offered by GSC are:

  • Helpdesk support for general queries and incident notifications from users on Galileo.
  • Information about the system status and notifications on important events affecting the system. In addition, registered users can subscribe to be informed in real time about events affecting Galileo services. One example is the publication of Notice Advisory to Galileo Users (NAGUs), which inform regularly about the system status.
  • Electronic Library, including Programme Reference documentation and general information.
  • Support to GNSS developers, including the GNSS Simulation and Testing Infrastructure (GSTI).
  • Provision of Galileo system data.
  • Promotion of GNSS and Galileo in particular.
  • Interface with other GNSS Service Providers.
  • Monitoring of the service and measuring the level of satisfaction of Galileo and the GSC in order to propose improvements and evolve the service accordingly.

Top

What is a NAGU?

The Notice Advisory to Galileo Users (NAGU) aims to inform the user community about the status of the Galileo constellation and, in particular, the occurrence and recovery of Signal in Space (SiS) outages. The SiS alert and warning indications received in real time by the user receivers always take precedence over the NAGU information received offline by an end user. NAGUs are published on the GSC web portal and automatic notifications to GSC registered users are sent once a new NAGU has been released. NAGUs are issued both for Planned and Unplanned events, and for General Notices regarding Galileo System as well as, for example, to notify users about the launch of new satellites. For more information about NAGUs, its format and templates, please, visit GSC site section NAGU information.

Top

Where can I find information about the Galileo constellation status?

Updated information on the status of the Galileo constellation can be found in the “Constellation Status” section under “Service Status” menu of GSC Website.

Top

What are the Galileo Almanacs? How do I use them?

The almanac data is a reduced-precision subset of the clock and ephemeris parameters of the active satellites in orbit. The almanac data allow to compute a raw estimation of the satellite coordinates, which is needed for signal acquisition by the receiver. The user receiver utilises the algorithm described in the Galileo Open Service Signal-In-Space Interface Control Document (OS SIS ICD) to compute the positions of the Galileo satellites. The definition of the Galileo almanac parameters can be found in section 5.1.10 of the OS SIS ICD.

Top

How can I test if my smartphone is receiving Galileo signals?

To check if a smartphone receives any Galileo satellite signals, there are several apps available in your app store such as GPSTest app (only available for Android). The application takes some time to locate the satellites. To make sure that the device tracks Galileo satellites, it is needed to be in an open space and without wifi or data connection enabled, to avoid getting almanacs from the internet. To have an idea of what can be seen on your phone, you can watch the following video. Additionally, some useful help information to test the device can be found in the following document.

Top

What are the Galileo Satellite Metadata? How do I use them?

The Galileo Satellite Metadata is information about the satellite properties which need to be known in order to properly implement advanced processing algorithms for precise orbit determination or Precise Point Positioning (PPP). This includes physical characteristics (such as mass, area or reflectivity), the attitude law and antenna parameters.

Top

Is the GSC services portfolio offered to users going to increase? How?

Yes, when fully developed, the European GNSS Service Centre (GSC) will offer a range of additional services, such as:

  • Providing the interfaces between the Galileo System and the new services (HAS, CAS, OSNMA).
  • Supporting the management of future services. Increase the number of Galileo-related products.
  • Providing service performance assessment forecasts.
  • Providing orbital products to SAR users.

Top

How do I know if my equipment is Galileo enabled?

In www.usegalileo.eu website it is possible to consult a complete list of different Galileo enabled receivers, chipsets or modules that can be found on the market classified by sector and type of device.

Top

Are there multi-constellation receivers capable of using GPS, Galileo, Glonass and others?

According to a recent EUSPA-supported study, chipset and receiver manufacturers are already equipping their devices with multi-constellation capabilities, including Galileo, and taking advantage of available services. In fact, the vast majority of current receivers are multi-constellation, and the most popular way to provide multi-constellation support is to cover all constellations, which represents over 30% of receivers.

To further increase the level of Galileo integration, EUSPA continues to work directly with chipset and receiver manufacturers. Through user consultations, technology workshops, sharing Galileo updates, co-marketing efforts, and dedicated funding for receiver development projects and studies, EUSPA is working with manufacturers to build an even better navigation experience.

EUSPA also launched its Fundamental Elements programme, a new research and development (R&D) funding mechanism supporting the development of chipsets and receivers. The programme will run through 2020 and has a projected budget of over EUR 100 million. The main objective of the initiative is to facilitate the development of applications across different sectors of the economy and promote the development of such fundamental elements as Galileo-enabled chipsets and receivers.

Top

Can I use Galileo on my mobile phone?

There are already over 700 million Galileo-enabled smartphones on the market and this number is increasingly rapidly.

Click here to find out if your phone is Galileo-enabled.

Top

Can I use Galileo in my car?

Galileo- enabled navigation devices for your car are already available on the market. What’s more, since April 2018, all new type approved vehicles sold in Europe are Galileo capable as part of a requirement to comply with the EU’s eCall emergency response system regulation.

Click here to find out if your navigation device is Galileo-enabled.

Top

Where can companies get information to help them develop products and services to take advantage of Galileo signals?

The European GNSS Service Centre (GSC) is the place to go for all things related to developing Galileo-capable products and services.

The GSC can be contacted at www.gsc-europa.eu

Top

Can I use Galileo enabled devices in other regions of the world?

Yes, Galileo offers its services worldwide with no restrictions in the use of its signal in any place of the planet, unless local governments do not allow access to any of the specific services.

EUSPA works with other countries and GNSS systems to enable and harmonise the Galileo services provision. For instance, the U.S. Federal Communications Commission (FCC) granted the access to specific signals transmitted by Galileo in all the devices in the United States of America.

More information can be found here

Top