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Galileo General Introduction
| GALILEO | |
|---|---|
| Title | Galileo General Introduction |
| Author(s) | GMV |
| Level | Basic |
| Year of Publication | 2011 |
The Galileo is a space-based global navigation satellite system (GNSS) that provides reliable positioning, navigation, and timing services to users on a continuous worldwide basis -- freely available to all. GALILEO receivers compute their position in the Galileo Reference System using satellite technology and based on triangulation principles.
Introduction
A user will be able to take a position with the same receiver from any of the satellites in any combination. By offering dual frequencies as standard, Galileo will deliver real-time positioning accuracy down to the meter range. It will guarantee availability of the service under all but the most extreme circumstances and will inform users within seconds of a failure of any satellite. This will make it suitable for applications where safety is crucial, such as running trains, guiding cars and landing aircraft.
Based on the award of the contracts for the first order of satellites, the launch services, the system support services and the operations, the European Commission announced the Initial Operational Capability (IOC) with three initial services to be provided in 2014/2015: an initial Open Service, an initial Public Regulated Service and an initial Search and Rescue Service. At this stage, accuracy and availability will not yet have reached their optimum level, the Safety-of-Life Service and the Commercial Service will be tested and will be provided as the system reaches full operational capability with the 30 satellites[1].
Galileo will ensure Europe's independence in a sector that has become critical for its economy and the well-being of its citizens.
GPS (US), GLONASS (Russia) and the other regional systems developed by Japan and China are military systems under military control – indeed they provide a civil service but that civil service could be either switched off or made less precise when desired e.g. in case of conflict. The world has become so dependent on services provided by satellite navigation in our daily lives that should a service be reduced or switched off, the potential disruption to business, banking, transport, aviation, communication, etc., to name but a few, would be very costly (e.g. in terms of revenues for business, road safety, etc.).
The combination of Galileo and GPS signals (inter-operability) in dual receivers will open the door to new GNSS applications that require a higher level of precision than currently available with GPS alone. From most locations, six to eight Galileo satellites will be visible which, in combination with GPS signals, will allow positions to be determined up to within a few centimetres. Examples of these applications are: guide the blind, increase the success rate of rescue operations in the mountains, monitor the whereabouts of people suffering from Alzheimer Disease, etc.
In addition, Galileo will improve the overall availability and coverage of GNSS signals. For example, the higher number of satellites will improve the availability of the signals in high rise cities where buildings can obstruct signals from satellites that are low on the horizon.
With Galileo, Europe will be able to exploit the opportunities provided by satellite navigation to the full extent. GNSS receiver and equipment manufacturers, application providers and service operators will benefit from novel business opportunities[2].
History and Development
As far back as the 1990s, the European Union saw the need for Europe to have its own global satellite navigation system. The conclusion to build one was taken in similar spirit to decisions in the 1970s to embark on other well-known European endeavours, such as the [Ariane] launcher and the Airbus. The European Commission and European Space Agency joined forces to build Galileo, an independent European system under civilian control. The definition phase and the development and In-Orbit Validation phase of the Galileo program were carried out by the European Space Agency (ESA) and co-funded by ESA and the European Community. The Full Operational Capability phase of the Galileo program is fully funded by the European Community and managed by the European Commission. The Commission and ESA have signed a delegation agreement by which ESA acts as design and procurement agent on behalf of the Commission. The Galileo program has been structured according to three main phases [2]: 1. In-Orbit Validation (IOV) phase: The IOV phase consists of qualifying the system through tests and the operation of two experimental satellites and a reduced constellation of four operational satellites and their related ground infrastructure. The two experimental satellites were launched in respectively December 2005 and April 2008. Their purpose was and is to characterize the Medium-Earth Orbit (MEO) environment (radiations, magnetic field etc) and to test in such environment the performance of critical payload technology (atomic clocks and radiation hardened digital technology). They also provide an early experimental signal-in-space allowing securing the frequency spectrum required for Galileo in accordance with WRC RNSS allocations. The launch of the first two operational satellites is scheduled for end of 2011. 2. Initial Operational Capability (IOC) phase: The IOC stage will be the partial commissioning of the ground and space infrastructure as from 2014-2015 and the provision of the open service, the search and rescue service and the PRS. While this first stage will be sufficient to test the services it should nonetheless be as short as possible, because it will not allow the system's full potential to be exploited and will not meet the requirements of all users. 2. Full Operational Capability (FOC) phase: The FOC phase consists of the deployment of the full system which will consist of 30 satellites, control centres located in Europe and a network of sensor stations and uplink stations installed around the globe. Galileo's Full Operational Capability (FOC) should be achieved in 2019-2020, in a staggered approach from the IOC phase. It might change, depending on availability of financing, technical problems and industrial performance.