Signal performance analysis of the latest quartet of Galileo satellites during the first operational year

Abstract

On 12 February 2020, the latest four Galileo satellites had completed one full year of space operational service. The satellites were launched on 25 July 2018. The quartet increased the operational capacity of the Galileo constellation to 22 satellites. This study reports on three signal-in-space (SiS) performance indicators-status, availability, and ranging accuracy-from 11 February 2019 to 12 February 2020. In addition, the study looks also at how the on-board satellite clocks have performed. The data analysis shows 100% data validity and signal health status for three our of the four satellites, whereas NAPA (No Accuracy Prediction Available) events accounted for about 2% of the time. In addition, SiS availability was higher than 95% in the first operational year. Furthermore, the 95th percentile of the global average of the instantaneous signal in space error is found to vary between 0.17 to 0.33 m on monthly basis. Lastly, the precise satellite clock biases show high short-term performance with 0.1 ps/s (10 −13 s/s) standard deviations during the first operational year. The numerical results indicate a robust performance and high reliability for the youngest Galileo satellites in the constellation. They increase the number of operational satellites in the constellation and thus contribute to the Galileo's increased popularity in the satellite-based positioning and navigation user community.

Galileo L10 Satellites: Orbit, Clock and Signal-in-Space Performance Analysis

“…These results are different from [ 22 ] where the analysis was carried out on the satellite clock corrections derived from the IGS CODE precise product. Nevertheless, the same precise products are used here to assess the accuracy metric for the broadcast satellite clock corrections.…”

“…The satellite clock corrections suggest good broadcast clock performance all four Galileo L10 satellites. The findings presented here are in line with Andrei et al [ 22 ] results that used the precise clock correction product.…”

“…This research complements our previous results [ 22 ] on the Galileo L10 satellites, the youngest members of the Galileo constellation. This paper provides the following three contributions.…”

“…Only the complete months after being declared operational are included. The results for 2019 were explained in detail in our previous research [ 22 ]. Nevertheless, we recall here that the main reasons for the lower availability numbers were the planned outage (April 2019), the Galileo incident (July 2019) and transmission of No Accuracy Prediction Available (NAPA) events during a specific month (e.g., November 2019).…”

“…Neither of the previous studies report results related to the Galileo L10 satellites. Andrei et al [ 22 ] were among the first to report performance indicators related to the Galileo L10 satellites during their first operational year. The authors reported monthly values variations for the signal-in-space ranging accuracy from 0.17 to 0.33 m. In addition, on-board satellite clock performance derived from the precise clock products was found to be very high, with picosecond level variations and about s/s standard deviation.…”