The Galileo system is the European-led global navigation satellite system. The system will provide position determination, navigation, timing, and communication services world-wide, to global user communities. The Galileo system will provide different levels of services for professional users, mass market, and safety of life applications. The set of services, clearly defined by their performance and availability will be provided on a global, regional, or local level.
The main objectives of the GALA project were:
- To provide the mission and system requirements, taking inputs from the application task, Geminus study and from past studies (ESA comparative system study), and including a focus on navigation, communication and search and rescue (derived from Sargal study outputs) requirements as well as revenue generation, international, legal and standardisation issues. To perform technical trade-offs related to Galileo navigation function and the potential communication function, as key inputs for architecture tasks.
- The navigation signals are considered in a specific trade-off analysis, including the signal structure and the cryptology associated with access control.
- The deployment strategy, the support to operations and the integrated logistic support (ILS) concepts are analysed and requirements are derived.
- A technical baseline document is produced in order to provide an updated issue of open trade-off and scenarios to be analysed by architecture and component design activities.
The implementation plan first defined the main programme phases: definition, design and development, validation, deployment and replenishment. Then three scenarios were considered: a final operational capability (FOC) with 30 satellites in 2008, a FOC with 30 satellites in 2008 with an initial operational capability (IOC) with 24 satellites before 2007, and finally a FOC with 30 satellites in 2006.
The assessment of the scenarios considered a set of key parameters: in-orbit validation effectiveness, success of the deployment schedule, certification feasibility and operational capability effectiveness. As a conclusion, the third scenario is proposed to be discarded because of the various criticalities identified, and the scenario two is proposed to be the baseline due to its better certification feasibility and operational capability effectiveness.
The overall Galileo requirements have been derived from these analyses and from the identification of design requirements.
First, the proposed security policy identified the need for dedicated encrypted services for strategic applications to allow full availability in periods of crisis or conflicts. Second, the integration of EGNOS has been determined following a two steps approach: first an optimisation of Galileo architecture, then an optimisation of the integration of EGNOS, in terms of services and in terms of architecture. A set of objectives were fixed, e.g. no impact on EGNOS development plan, guaranty of the continuity of EGNOS service. The optimisation proposed a phased approach, based on a unique step to accommodate GPS modernisation involving the new L5 frequency as well as Galileo integrity monitoring.
The cost of Galileo infrastructure up to the FOC is estimated at approximately EUR 3.2 billion. Target recurrent costs of user terminals are also provided.
Concerning Galileo benefits, the analysis considered the period 2001-2020 and provided annual supplier and user net benefits, as well as social benefits. Total benefits are estimated at EUR 74 billion over the period, from which EUR 6 billion shall be subtracted for the investment costs. Annual curves are provided, showing positive net benefits after 2008 and a predominance of user benefits over producer benefits, which confirms the value of Galileo as a public good. The result is an IRR of around 75 %, and a high growth of employment resources.