The GSSF allows the end-user to simulate all the segments of the Galileo System. So that, the user can simulate:

• The Space Segment, the GSSF provides models of the Galileo and GPS constellations

• The User Segment, in order to analyse navigation and integrity performances at user level, the GSSF models the user receiver and internal algorithms that compute the Galileo Figures of Merit

• The Ground Segment, models of the Galileo Ground segment are provided to support analyses with the stations location and the determination of the monitored satellites

• The Environment, sources of perturbation can be added to the scenario to simulate the effect of the atmosphere, multipath and receiver noise on the navigation system performances