GNSS CS Purpose RNAV

The control segment, headquartered in the USA but with monitoring units all over the world, managing the satellites' performance, uploads navigation data and monitors the satellites (including for ephemeris - the deviation from the planned path). The space segment (or SPSSPS —1) Pressure: Standard Pressure Setting (1013.25hPa)2) GNSS: Space Segment) comprises the satellites themselves. As the user segment never sends signals back to the satellites, there is no way that the control segment can monitor the users of GPSGPS —Global Positioning System (USA) - or that the number of users can be limited.

There are several variants of this question on the exam, so ensure you know all the roles the control segment has to play.