Ai Qingsong, Maciuk Kamil, Lewinska Paulina, Borowski Lukasz
State Key Laboratory of Geodesy and Earth's Dynamics, Innovation Academy for Precision Measurement Science and Technology, Wuhan 430071, China.
University of Chinese Academy of Sciences, Beijing 100049, China.
Sensors (Basel). 2021 Mar 30;21(7):2396. doi: 10.3390/s21072396.
This research is focused on searching for frequency and noise characteristics for available GNSS (Global Navigation Satellite Systems). The authors illustrated frequency stability and noise characteristics for a selected set of data from four different GNSS systems. For this purpose, 30-s-interval clock corrections were used for the GPS weeks 1982-2034 (the entirety of 2018). Firstly, phase data (raw clock corrections) were preprocessed for shifts and removal of outliers; GLONASS and GPS satellites characterize a smaller number of outliers than BeiDou and Galileo clock products. Secondly, frequency and Hadamard deviation were calculated. This study concludes that the stability of GPS and Galileo is better than that of BDS (BeiDou Navigation Satellite System) and GLONASS. Regarding noise, the GPS, Galileo, and BDS clocks are affected by the random walk modulation noise (RWFM), flashing frequency modulation noise (FFM), and white frequency modulation noise (WFM), whereas the GLONASS clocks are mainly affected only by WFM.
本研究聚焦于寻找现有全球导航卫星系统（GNSS）的频率和噪声特性。作者阐述了从四个不同GNSS系统中选取的一组数据的频率稳定性和噪声特性。为此，在2018年全年使用了1982 - 2034年GPS周的30秒间隔时钟校正。首先，对相位数据（原始时钟校正）进行预处理，以消除偏移和异常值；与北斗和伽利略时钟产品相比，格洛纳斯和GPS卫星的异常值数量较少。其次，计算了频率和哈达玛偏差。本研究得出结论，GPS和伽利略的稳定性优于北斗卫星导航系统（BDS）和格洛纳斯。在噪声方面，GPS、伽利略和BDS时钟受到随机游走调制噪声（RWFM）、闪烁频率调制噪声（FFM）和白频率调制噪声（WFM）的影响，而格洛纳斯时钟主要仅受WFM影响。
