Past, present and future of atomic clocks for GNSS

Abstract

Global Navigation Satellite Systems (GNSS) are enabled by atomic clocks, which provide the timing precision and accuracy required for the ranging measurements. Significant investments have been made and will continue to be made, to improve GNSS atomic clock technology and reduce the signal-in-space user range error. After providing a baseline by reviewing current GNSS satellite atomic clock technology, we discuss how far, and in what directions, atomic clock technology should be pushed to provide maximum benefits to GNSS performance, reliability and cost.