A new GNSS multi constellation simulator: NAVYS

With the multiplication of navigation systems (GPS, GALILEO, GLONASS, QZSS, …) and the large variety of signals to be received, GNSS constellation simulators need to be more and more flexible. In the scope of its navigation activities, the CNES has expressed the need for a simulator that, in addition to allow the test of a large variety of receivers, satisfies a twofold objective: the emulation of a propagation channel representative of degraded environments, typically indoor or urban and high level of flexibility to generated new type of signals in order to assess the performances of future GNSS systems. For that purpose, Thales Alenia Space and Elta are currently developing a highly flexible and modular GNSS constellation simulator under CNES contract. In this development, they take benefit of their experience inherited from the realization of a flexible NSGU modulator that can handle a large diversity of modulations and can cope with most of the current and future GNSS systems. These modulations comprise BOC, BPSK, ALTBOC, CBOC, TMBOC, on selectable frequency bands. This paper describes the GNSS multi constellation simulator (NAVYS) design and architecture, includes validation test results and presents the status of the development of this equipment.