GALILEO Satellite Radio Navigation System

GALILEO is the joint project of the European Commission and the European Space Agency to deploy a new infrastructure based on a 30-satellite constellation, to provide positioning and timing services. On 26 March 2002, the European Union released €450 million to fund the development of the GALILEO satellite radio navigation system, which will enable people to pinpoint their exact position or the location of any moving or stationary object to within 1m. The European Space Agency had already committed a similar amount. The estimated cost of GALILEO is €3.4 billion and it is expected to be operational in 2008.

Although the impact of satellite global positioning on society and industrial development is not yet clear, Europe cannot afford to rely on technologies and systems developed outside it, as GPS is certain to be one of the largest industries of the 21^st Century.

In the field of telecommunications, allied with other new technologies such as GSM or UMTS, GALILEO will increase the potential to provide positioning information as well as to provide combined services of a very high level.

EXISTING RADIO NAVIGATION SATELLITES

Currently there are two radio navigation satellites in the world: American (GPS) and Russian (Glonass). Both were designed as military systems, but the GALILEO system appears to offer the only real alternative to the American system.

Advantages of GAILILEO over GPS include:

• GALILEO has been designed and developed as a non-military application, while nonetheless incorporating all the necessary protective security features. Unlike GPS, which was essentially designed for military use, GALILEO provides, for some of the services offered, a very high level of continuity required by modern business, in particular with regard to contractual responsibility
• It is based on the same technology as GPS and provides a similar - and possibly higher - degree of precision, thanks to the structure of the constellation of satellites and the ground-based control and management systems planned
• GALILEO is more reliable as it includes a signal "integrity message" informing the user immediately of any errors. In addition, unlike GPS, it will be possible to receive GALILEO in towns and regions located in extreme latitudes
• It represents a real public service and, as such, guarantees continuity of service provision for specific applications. GPS signals, on the other hand, in recent years have on several occasions become unavailable on a planned or unplanned basis, sometimes without prior warning

GALILIEO also complements GPS:

• Using both infrastructures in a coordinated fashion (double sourcing) offers real advantages in terms of precision and in terms of security, should one of the two systems become unavailable
• The existence of two independent systems is of benefit to all users since they will be able to use the same receiver to receive both GPS and GALILEO signals

EGNOS

EGNOS, which has been developed since 1993, offers major improvements to the services offered in Europe by the GPS and Glonass satellite constellations. EGNOS increases the number of GPS signals, applies a differential correction, adds an integrity message and is also set to be incorporated into GALILEO. The GALILEO system is vital to European hopes to be considered as a viable partner to the US.

GALILEO SERVICES

The various service requirements and the associated commercial and security aspects can be rationalised into five distinct service groups:

• Open Services (OS)
• Commercial Services (CS)
• Safety-Of-Life Services (SAS)
• Public Regulated Services (PRS)
• Search-And-Rescue Services (SAR)

In addition, Navigation Related Communication Service (NRS) will be implemented under the Commercial Service frame. Furthermore, Combined Services will be implemented, such as:

• GALILEO combined with GPS and augmented by EGNOS, so called GALILEO-GPS-EGNOS Services
• GALILEO services combined with services provided by Local Components
• Combined GALILEO and GMS, UMTS services

SYSTEM ARCHITECTURE

The GALILEO system architecture will be designed in such a way as to permit:

• Adaptation of the response to the needs of users and to market trends
• Minimisation of development and operating costs
• Minimisation of the risks, other than financial risks, inherent in a project so unusual by virtue of its scope, complexity and the challenges it poses
• Interoperability with existing systems, notably GPS, while at the same time maintaining autonomy and competitiveness

Architecture is made up of four components:

Global Component - the central component will be the global constellation of 30 satellites, distributed over three planes in Medium Earth Orbit (MEO). Within each plane, one satellite is an active spare, able to be moved to any of the other satellite positions within its plane, for replacement of a failed satellite. This will be complemented by regional and local components.

Regional Components - the service provided by GALILEO is global and this includes the delivery of integrity worldwide. However, the design of the system is such as to permit the introduction of rdata from regional service providers using authorised integrity up-link channels provided by GALILEO, thereby making it possible to "personalise" integrity under partnership agreements with the relevant countries. The cost of this component will be borne by the region in question.

Local Components - the GALILEO system will provide a high level of performance to users worldwide, even in places where there is no ground infrastructure. However, in the case of specific applications in given areas, even more demanding levels of positioning performance will be necessary or, alternatively, integration with other functions, e.g. local communications, will confer added value on the basic service.

User Receivers and Terminals - receivers will be the crucial link in the GALILEO chain and will need to satisfy market requirements:

• Competitive performance and costs compared with the existing systems
• Adequate tailoring to the needs of users (general public and the professional market)
• Potential for change and integration of the services (e.g. communications)
• Possibility of multi-modal use

ECONOMIC ADVANTAGES

The GALILEO system has already created 140,000 jobs and, with a cost equivalent to 150km of semi-urban motorway, will generate a market estimated to have a value of €9 billion per year. It will also lower Europe's dependence on GPS for vital economic areas such as mobile telecom networks or financial transactions.

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