Straightforward estimations of GNSS on-board clocks

In this paper, we present two techniques to estimate GNSS on-board clocks. These techniques only require a single GNSS receiver and allow to evaluate the stability on a given pass of the time difference between the GNSS on-board clock and the clock that drives the GNSS receiver. These methods have been validated using IGS clock products for GPS on-board clocks. We also show that they can be used to characterize ground clocks provided a better space clock is available.