A Master/Slave "Ensembling" Procedure for Satellite-System Timekeeping

James Camparo and Travis Driskell

Abstract:	Simplification of space-system timekeeping algorithms is not only advantageous from a computational perspective, but also from a reliability perspective: with “simple” space-system algorithms there is a better chance of understanding how the system will respond to diverse, abnormal events (e.g., losing and then regaining a satellite-to-satellite communications link, loss of clock temperature control on a space vehicle, etc.). Here, we introduce a relatively simple Master/Slave ensembling algorithm for satellite clocks, where one clock in the constellation is designated the master, and all other clocks tie their time to the master via crosslink time-transfer. Every TMCT, the master designation changes from one satellite to another, so that over times long compared to TMCT the system’s timekeeping variations are defined by an ensemble average of the space clocks. Our results indicate that Master/Slave ensembling is a simple yet viable approach to space-system synchronization as demonstrated with two realistic examples: 1) a constellation of lower-quality ultraminiature CubeSat clocks working in combination with several high-quality atomic clocks carried on larger spacecraft, and 2) a constellation of lower-quality ultraminiature CubeSat clocks operating on their own.
Published in:	Proceedings of the 51st Annual Precise Time and Time Interval Systems and Applications Meeting January 21 - 24, 2020 Hyatt Regency Mission Bay San Diego, California
Pages:	302 - 309
Cite this article:	Camparo, James, Driskell, Travis, "A Master/Slave "Ensembling" Procedure for Satellite-System Timekeeping," Proceedings of the 51st Annual Precise Time and Time Interval Systems and Applications Meeting, San Diego, California, January 2020, pp. 302-309. https://doi.org/10.33012/2020.17318
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