Dissertation

Time Transfer Architectures for Small Satellite Platforms

Flood, Christopher W

2024

Overview

Constellations of small satellites are playing an increasing role in supporting global communication, Earth observation, and positioning, navigation and timing (PNT). All of these applications require some level of accurate timing and frequency control onboard; however, the specific performance requirements differ dramatically. The research in this dissertation describes both radio frequency (RF) and optical techniques to support small satellite applications requiring timing between the nanosecond and femtosecond range. Radio frequency techniques are applied to a low size, weight, and power (SWaP) clock hardware testbed for sub-ns clock comparison between oscillators on separate software defined radio (SDR) platforms. The multi-platform configuration is used to demonstrate extensible timescale formation approaches, with an ensemble realization having frequency stability 1.5e-12 at 10,000 seconds. A second study presents development of a frequency comb-based optical system capable of sub-femtosecond time transfer and nanometer ranging, which can support future astronomical sensing missions. A free space experiment was conducted between the National Institute of Standards and Technology (NIST) and the University of Colorado Boulder to evaluate performance of a reduced SWaP system, which achieved sub-femtosecond time transfer and sub-micrometer ranging precision. Experimental results are comparable to previous NIST laboratory demonstrations, indicating only a minor degradation in precision when reducing SWaP. The research within this thesis outlines radio frequency and optical timekeeping techniques applicable to navigation from future satellite constellations and science missions using clusters of small satellites.

• Publisher: ProQuest Dissertations & Theses
• Subject: Aerospace engineering / Communication / Remote sensing
• ISBN: 9798346876878