A Multi-Platform Clock Ensemble Testbed

Scalable methods for the precise distribution of time and frequency across clusters or constellations of small satellites are sought-after in support of positioning, navigation, and timing (PNT), scientific, and communication needs. This paper builds on previous work [1,2] and explores next steps in modeling inter-satellite clock comparison using an upgraded testbed designed to represent a distributed ensemble across a small cluster of two satellites, each with a low size, weight, and power (SWaP) clock onboard. The work presented in this paper models the small satellite timing system using software defined radios (SDR), improved signal steering methods, and the combination of these concepts into a multi-platform clock ensemble. Results show a diverse ensemble capable of generating a steered signal that exhibits the short term stability of an Orolia miniaturized rubidium oscillator (mRO) [3] and the long term stability of a Microsemi SA.45s chip scale atomic clock (CSAC) [4] with a smooth transition across stability regions.