Finnish Geospatial Research Institute, National Land Survey of Finland, 02430 Masala, Finland.
Department of Space, Earth and Environment, Onsala Space Observatory, Chalmers University of Technology, 412 96 Göteborg, Sweden.
Sensors (Basel). 2021 Mar 1;21(5):1695. doi: 10.3390/s21051695.
The tenth launch (L10) of the European Global Navigation Satellite System Galileo filled in all orbital slots in the constellation. The launch carried four Galileo satellites and took place in July 2018. The satellites were declared operational in February 2019. In this study, we report on the performance of the Galileo L10 satellites in terms of orbital inclination and repeat period parameters, broadcast satellite clocks and signal in space (SiS) performance indicators. We used all available broadcast navigation data from the IGS consolidated navigation files. These satellites have not been reported in the previous studies. First, the orbital inclination (56.7±0.15°) and repeat period (50680.7±0.22 s) for all four satellites are within the nominal values. The data analysis reveals also 13.5-, 27-, 177- and 354-days periodic signals. Second, the broadcast satellite clocks show different correction magnitude due to different trends in the bias component. One clock switch and several other minor correction jumps have occurred since the satellites were declared operational. Short-term discontinuities are within ±1 ps/s, whereas clock accuracy values are constantly below 0.20 m (root-mean-square-rms). Finally, the SiS performance has been very high in terms of availability and accuracy. Monthly SiS availability has been constantly above the target value of 87% and much higher in 2020 as compared to 2019. Monthly SiS accuracy has been below 0.20 m (95th percentile) and below 0.40 m (99th percentile). The performance figures depend on the content and quality of the consolidated navigation files as well as the precise reference products. Nevertheless, these levels of accuracy are well below the 7 m threshold (95th percentile) specified in the Galileo service definition document.
第十次发射（L10）的欧洲全球导航卫星系统伽利略号填补了星座中的所有轨道槽。这次发射携带了四颗伽利略卫星，于 2018 年 7 月进行。这些卫星于 2019 年 2 月宣布投入运行。在这项研究中，我们报告了伽利略 L10 卫星在轨道倾角和重复周期参数、广播卫星时钟和空间信号性能指标方面的性能。我们使用了 IGS 综合导航文件中所有可用的广播导航数据。这些卫星以前的研究中没有报告过。首先，四颗卫星的轨道倾角（56.7±0.15°）和重复周期（50680.7±0.22 s）都在标称值范围内。数据分析还揭示了 13.5、27、177 和 354 天的周期信号。其次，广播卫星时钟由于偏置分量的不同趋势显示出不同的校正幅度。自卫星投入运行以来，已经发生了一次时钟切换和几次其他较小的校正跳变。短期不连续性在±1 ps/s 以内，而时钟精度值始终低于 0.20 m（均方根-rms）。最后，从可用性和精度方面来看，空间信号性能非常高。每月的 SiS 可用性一直稳定在 87%的目标值以上，2020 年比 2019 年高得多。每月的 SiS 精度低于 0.20 m（95%分位数）和 0.40 m（99%分位数）。这些性能数据取决于综合导航文件的内容和质量以及精确的参考产品。然而，这些精度水平远低于伽利略服务定义文件中规定的 7 m 阈值（95%分位数）。
