Spacecraft Atomic Clock Flight Simulation and Test Station: Slaving a Crystal Oscillator Clock to a Master Atomic Clock

He Wang, Gebriel H. Iyanu, Dylan L. Caponi

Abstract:	In this paper we present a hardware/software satellite constellation timekeeping simulation and testing system and report the results of a three-clock synchronization experiment, in which a crystal oscillator clock is slaved to a Master Rb atomic clock while the Rb clock is independently synchronized to a Cs reference clock. With this Slave-Master-Cs timekeeping scheme and a real-time linear regression algorithm developed in this work, we demonstrate that the long-term frequency drift rate of the crystal oscillator clock is significantly reduced from 1.1 ? 10-11 per day to 1.8 ? 10-13 per day, effectively making the crystal oscillator clock as stable as an Rb atomic clock. In addition, we also validate that our real-time linear regression timekeeping algorithm can efficiently detect and correct large frequency shifts caused by space environmental effects such as space vehicle temperature variation and solar flare induced radiation. The reported experimental results are useful references for system engineers and satellite operators in developing satellite timekeeping architectures and in resolving satellite constellation timekeeping operational issues.
Published in:	Proceedings of the 46th Annual Precise Time and Time Interval Systems and Applications Meeting December 1 - 4, 2014 Seaport Boston Hotel Boston, Massachusetts
Pages:	243 - 251
Cite this article:	Wang, He, Iyanu, Gebriel H., Caponi,  Dylan L., "Spacecraft Atomic Clock Flight Simulation and Test Station: Slaving a Crystal Oscillator Clock to a Master Atomic Clock," Proceedings of the 46th Annual Precise Time and Time Interval Systems and Applications Meeting, Boston, Massachusetts, December 2014, pp. 243-251.
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