Getting EGNOS Ready for Initial Operations

Jean-Yves Schneider, Christian Ruf, Patrick Rosenthal, Bernard Charlot, Marc Lemaire and Alan Fromberg

Abstract:	EGNOS is the European part of GNSS-1, aiming at space- based augmentation over Europe of the existing navigation satellite constellations, namely GPS and GLONASS. This paper reviews major issues related to the overall verification of the EGNOS system up to readiness for initial operations. The objective of the Assembly, Integration and Verification (AIV) of EGNOS is to demonstrate that the system is compliant with its requirements and ready for initial operations. This objective is achieved by performing verification activities at different phases of the development process. First, analysis and simulation results are obtained during the subsystem and system design phases that contribute to an early assessment of system operability and performances. Then, many testing, inspection and demonstration activities are necessary to progressively verify the implementation of the subsystems. This is completed by a system factory integration of the subsystems and verification of the resulting chains. Finally, the deployed system is verified on both functional and performance aspects. To that extent, the AIV objective will not be achieved in a single step. Intermediate achievements will constitute a progressive increase of confidence in the verification of the EGNOS ground segment and system. Thus, the verification process is broken down into milestones that are referring to technical objectives. At each milestone along the verification process, the results achieved at engineering, subsystem AIV or system AIV levels are recorded and used as the basis of the decision to proceed to the next phase. These decisions shall adequately reflect programmatic concerns such as risk mitigation and schedule optimisation. This paper describes: • how these milestones are organised and what are the trade-off to be considered in order to ensure the right balance between programmatic constraints and engineering requirements • how this process is implemented to verify system aspects of different nature thereby covering the variety of technology involved in EGNOS: wide area network, radio frequency, operational aspects, statistical performances, etc. • how this process ends up with the demonstration that the EGNOS system is ready for initial operations.
Published in:	Proceedings of the 15th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GPS 2002) September 24 - 27, 2002 Oregon Convention Center Portland, OR
Pages:	2648 - 2656
Cite this article:	Schneider, Jean-Yves, Ruf, Christian, Rosenthal, Patrick, Charlot, Bernard, Lemaire, Marc, Fromberg, Alan, "Getting EGNOS Ready for Initial Operations," Proceedings of the 15th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GPS 2002), Portland, OR, September 2002, pp. 2648-2656.
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