GNSS Stability Monitoring using the Three-Cornered Hat Method

Ciro Gioia, Daniele Borio, Sophie Damy

Abstract:	The three-cornered hat method allows the evaluation of the individual stabilities of the clocks in a set of at least three devices. This approach is adopted here to analyse the stability of Global Navigation Satellite Systems (GNSSs) when considered in a multi-constellation scenario with at least three systems. The Intersystem (IS) biases and drifts between GPS, Galileo and GLONASS are computed and the three-cornered hat method is used to estimate the individual Allan Variances (AVARs) of the different systems. While the obtained stabilities are affected by propagation effects and by receiver processing, they provide useful indications on the timing performance achievable using individual GNSSs. The proposed approach is thoroughly tested using observables from three multi-constellation receivers that have been considered to assess the impact of different devices on the final system AVARs. Experimental results show that the AVARs obtained using professional receivers are very consistent and practically overlapping curves are obtained. Small degradations are observed when considering a low-cost commercial receiver. Consistent results were obtained considering measurements from different data collections. Moreover, the importance of Time-Receiver Autonomous Integrity Monitoring (T-RAIM) for Fault Detection and Exclusion (FDE) is highlighted when considering partially obstructed scenarios.
Published in:	Proceedings of the 50th Annual Precise Time and Time Interval Systems and Applications Meeting January 28 - 31, 2019 Hyatt Regency Reston Reston, Virginia
Pages:	177 - 190
Cite this article:	Gioia, Ciro, Borio, Daniele, Damy, Sophie, "GNSS Stability Monitoring using the Three-Cornered Hat Method," Proceedings of the 50th Annual Precise Time and Time Interval Systems and Applications Meeting, Reston, Virginia, January 2019, pp. 177-190. https://doi.org/10.33012/2019.16752
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