Short-term Stability of GNSS Satellite Clocks and its Effects on Precise Point Positioning

Anja Hesselbarth, Lambert Wanninger

Abstract:	Precise Point Positioning (PPP) requires the availability of precise orbit and clock corrections for all satellites used. Unfortunately, only two Analysis Centers (AC) of the International GNSS Service (IGS) make GLONASS clock corrections available. Both products consist of tabular clock values with 5 minute intervals, which is not dense enough for many kinematic PPP applications. Thus, mathematical interpolation of the satellite clock corrections is required. We densified the GPS/GLONASS clock corrections produced by the European Space Operation Centre (ESOC) using a carrier-phase based clock interpolation technique to 1 second intervals. Based on these high-rate corrections we analyzed the short-term stability of all GNSS clocks, determined satellite-individual statistical values of the errors due to a mathematical clock correction interpolation, developed an observation function which takes interpolation errors into account, and tested several PPP processing algorithms with kinematic GNSS observations. Adding GLONASS to GPS considerably improves PPP performance. Further shortening of convergence time and increase of accuracy are obtained if clock corrections at 30 second intervals are used. Performance improvement of combined GPS/GLONASS is achieved by using an observation weighting function which takes the short-term stability of the satellite clocks into account.
Published in:	Proceedings of the 21st International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS 2008) September 16 - 19, 2008 Savannah International Convention Center Savannah, GA
Pages:	1855 - 1863
Cite this article:	Hesselbarth, Anja, Wanninger, Lambert, "Short-term Stability of GNSS Satellite Clocks and its Effects on Precise Point Positioning," Proceedings of the 21st International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS 2008), Savannah, GA, September 2008, pp. 1855-1863.
Full Paper:	ION Members/Non-Members: 1 Download Credit Sign In