What is a Global Navigation Satellite System GNSS?
Global Navigation Satellite System (GNSS) refers to a constellation of satellites providing signals from space that transmit positioning and timing data to GNSS receivers. The receivers then use this data to determine location.
By definition, GNSS provides global coverage. Examples of GNSS include Europe’s Galileo, the USA’s NAVSTAR Global Positioning System (GPS), Russia’s Global’naya Navigatsionnaya Sputnikovaya Sistema (GLONASS) and China’s BeiDou Navigation Satellite System.
The performance of GNSS is assessed using four criteria:
- Accuracy: the difference between a receiver’s measured and real position, speed or time;
- Integrity: a system’s capacity to provide a threshold of confidence and, in the event of an anomaly in the positioning data, an alarm;
- Continuity: a system’s ability to function without interruption;
- Availability: the percentage of time a signal fulfils the above accuracy, integrity and continuity criteria.
This performance can be improved by regional satellite-based augmentation systems (SBAS), such as the European Geostationary Navigation Overlay Service (EGNOS). EGNOS improves the accuracy and reliability of GPS information by correcting signal measurement errors and by providing information about the integrity of its signals.
WHAT IS GALILEO
Galileo is Europe’s Global Satellite Navigation System (GNSS), providing improved positioning and timing information with significant positive implications for many European services and users.
- Galileo allows users to know their exact position with greater precision than what is offered by other available systems.
- The products that people use every day, from the navigation device in your car to a mobile phone, benefit from the increased accuracy that Galileo provides.
- Critical, emergency response-services benefit from Galileo.
- Galileo’s services will make Europe’s roads and railways safer and more efficient.
- It boosts European innovation, contributing to the creation of many new products and services, creating jobs and allowing Europe to own a greater share of the EUR 175 billion global GNSS market (GNSS Market and User Reports).
Furthermore, Galileo provides Europe and European citizens with independence and sovereignty, an array of environmental benefits and several new services specific to the Galileo programme (Open Service, Commercial Service, Search and Rescue).
A global player
Until now, GNSS users have had to depend on non-civilian American GPS or Russian GLONASS signals. With Galileo, users now have a new, reliable alternative that, unlike these other programmes, remains under civilian control.
While European independence is a principle objective of the programme, Galileo also gives Europe a seat at the rapidly expanding GNSS global table. The programme is designed to be compatible with all existing and planned GNSS and interoperable with GPS and GLONASS. In this sense, Galileo is positioned to enhance the coverage currently available – providing a more seamless and accurate experience for multi-constellation users around the world.
Satellite positioning has become an essential service that we often take for granted. Just think what would happen if GNSS signals were suddenly switched off. Truck and taxi drivers, ship and aircraft crews and millions of people around the world would suddenly be lost.
Furthermore, financial and communication activities, public utilities, security and humanitarian operations and emergency services would all come to a standstill. In other words, as the use of satellite-based navigation systems continues to expand, the implications of a potential signal failure become even greater.
With the addition of Galileo to the global GNSS constellation, we not only minimise these risks, but also ensure better performance and accuracy for the end-user.
What is EGNOS?
The European Geostationary Navigation Overlay Service (EGNOS) is Europe’s regional satellite-based augmentation system (SBAS) that is used to improve the performance of global navigation satellite systems (GNSSs), such as GPS and Galileo. It has been deployed to provide safety of life navigation services to aviation, maritime and land-based users over most of Europe.
EGNOS uses GNSS measurements taken by accurately located reference stations deployed across Europe. All measured GNSS errors are transferred to a central computing centre, where differential corrections and integrity messages are calculated. These calculations are then broadcast over the covered area using geostationary satellites that serve as an augmentation, or overlay, to the original GNSS message.
As a result, EGNOS improves the accuracy and reliability of GNSS positioning information, while also providing a crucial integrity message regarding the continuity and availability of a signal. In addition, EGNOS also transmits an extremely accurate universal time signal.
Benefiting numerous market segments
EGNOS is essential for applications where accuracy and integrity are critical. For example, in the aviation sector GNSS alone does not satisfy the strict operational requirements set by the International Civil Aviation Organisation (ICAO) for use in such critical flight stages as final approaches. However, with the addition of EGNOS, which has been certified for civil aviation since 2011, systems such as GPS can satisfy ICAO standards.
Beyond the aviation sector, EGNOS improves and extends the scope of such GNSS applications as precision farming, on-road vehicle management and navigating ships through narrow channels – to name a few.
Today, EGNOS is benefiting numerous market segments, including aviation, road, rail, maritime, surveying/mapping, location-based services and agriculture.
To learn more about EGNOS and its role in these sectors, visit the EGNOS Segment Pages.
What is the European GNSS Agency (GSA)?
By telling us exactly where we are and what time it is, Galileo and EGNOS – Europe’s independent satellite navigation programmes – are revolutionising transport, farming, logistics and our daily lives.
Driving this revolution is the European GNSS Agency (GSA), the only European Union agency working in space.
To accomplish this mission, the GSA is responsible for the operations and service provision for both programmes. This is no simple task, and one that requires us to wear multiple hats. For example, following the launch of a new Galileo satellite, the GSA manages the Early Orbit Phase (EOP), one of the most important phases of a space mission.
The responsibilities also include overseeing the operation of such key service facilities as the Galileo Security Monitoring Centre (GSMC) in France and in Spain, the European GNSS Service Centre (GSC) in Spain, the Galileo Reference Centre (GRC) in the Netherlands, the Galileo Control Centres (GCC) in Fucino and Oberpfaffenhofen and the Galileo Integrated Logistic Support Centre (GILSC) in Belgium. Collectively, these facilities ensure Galileo’s security and performance so that people can trust and rely on it in their daily lives and when they need it most.
Watch This: Linking space to user needs
Furthermore, the GSA is charged with maximising adoption of European GNSS across user market segments. By constantly working closely with a broad range of stakeholders, Galileo can now be found in applications and devices ranging from smartphones to wearables and from aircraft to personal vehicles. In fact, preliminary figures show that some 75 million Galileo-enabled smartphones were sold in 2017, and 95% of the chipsets on the market are Galileo-enabled. As of April 2018, all new models of cars sold in the EU must be equipped with Galileo as required by the eCall regulation. Galileo is also being increasingly used in drones to ensure smooth navigation and in Search and Rescue operations to save lives.
As a result of this impressive market uptake, today Galileo is providing millions of users with global positioning, navigation and timing information. You can get an up-to-date listing of all available Galileo compatible products at www.useGalileo.eu.
Since taking over the EGNOS service provision, the GSA has supported its expansion to benefit a wide range of users. For example, today hundreds of airports have EGNOS-based approaches, the vast majority of European farmers rely on EGNOS to enhance precision farming, and EGNOS has become the standard for mapping and surveying in Europe.
Click here to download our GSA Fast Facts brochure.
More information: https://www.gsa.europa.eu/
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.
What is the Galileo Information Centre – Chile?
The Galileo Information Centre is the information centre on the technologies and programs of the European Satellite Navigation Systems (EGNSS).
Based in Santiago de Chile, we offer support to the satellite navigation industry, application developers and end users in Argentina, Bolivia, Chile, Colombia and Ecuador .
The objectives of the Centre are to:
- Disseminate information about GALILEO and EGNOS to enhance local awareness and understanding of the European GNSS services in the region.
- Promote the implementation of activities related to European satellite navigation systems.
- Monitor local and regional initiatives that use satellite navigation technologies.
- Provide support to users in South America in the development of new applications through cooperation with the European industry.
- Support education and training on issues related to EGNSS.
Do I have to pay for the Galileo Information Centre-Chile Services?
The Galileo Information Centr–Chile Services are free of charge.
You can find more information about our services here.
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.
Who is involved in Galileo?
Galileo is a joint initiative of the European Commission, the European GNSS Agency 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 the GSA, which oversees how Galileo infrastructure is used and ensures that Galileo services are delivered as planned and without interruption.
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.
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 free?
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.
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.
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.
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 six spares. 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 2020 onwards. In a first phase, this will re-enforce the constellation with the deployment of spare satellites. After this, subsequent launches will be used for constellation replenishment purposes.
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.
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.
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.
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.
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
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.
What is the Galileo High Accuracy Service?
Galileo’s High Accuracy Service (HAS) will complement the Open Service by providing an additional encrypted navigation signal in a different frequency band. The HAS will allow users to obtain a positioning error below two decimetres. It will be based on the free transmission of Precise Point Positioning (PPP) corrections through the Galileo E6 signal.