Performance of the BDS3 experimental satellite passive hydrogen maser
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Various types of onboard atomic clocks such as rubidium, cesium and hydrogen have different frequency accuracies and frequency drift rate characteristics. A passive hydrogen maser (PHM) has the advantage of low-frequency drift over a long period, which is suitable for long-term autonomous satellite time keeping. The third generation of Beidou Satellite Navigation System (BDS3) is equipped with PHMs which have been independently developed by China for their IGSO and MEO experimental satellites. Including Galileo, it is the second global satellite navigation system that uses PHM as a frequency standard for navigation signals. We briefly introduce the PHM design at the Shanghai Astronomical Observatory (SHAO) and detailed performance evaluation of in-orbit PHMs. Using the high-precision clock values obtained by satellite-ground and inter-satellite measurement and communication systems, we analyze the frequency stability, clock prediction accuracy and clock rate variation characteristics of the BDS3 experimental satellites. The results show that the in-orbit PHM frequency stability of the BDS3 is approximately 6 × 10−15 at 1-day intervals, which is better than those of other types of onboard atomic clocks. The BDS3 PHM 2-, 10-h and 7-day clock prediction precision values are 0.26, 0.4 and 2.2 ns, respectively, which are better than those of the BDS3 rubidium clock and most of the GPS Block IIF and Galileo clocks. The BDS3 PHM 15-day clock rate variation is − 1.83 × 10−14 s/s, which indicates an extremely small frequency drift. The 15-day long-term stability results show that the BDS3 PHM in-orbit stability is roughly the same as the ground performance test. The PHM is expected to provide a highly stable time and frequency standard in the autonomous navigation case.
KeywordsPHM Atomic clock BDS3 TWSTFT Allan variance Clock prediction ISL
The IGS and GFZ are greatly acknowledged for providing the GNSS products. The authors are grateful for the comments and remarks of the reviewers and editors, which helped to improve the manuscript. This work was supported by the National key Research Program of China “Collaborative Precision Positioning Project” (Grant No. 2016YFB0501900), the National Natural Science Foundation of China (Grant No. 41574029), the Youth Innovation Promotion Association CAS (Grant No. 2016242) and Shanghai Science and Technology Committee Foundation (Grant No. 16511103003).
- Gong H, Ni S, Mou W, Zhu X, Wang F (2012). Estimation of COMPASS on-board clock short-term stability. In: Proceedings of European frequency and time forum (EFTF), pp 383–386Google Scholar
- Gonzalez Martinez FJ (2014). Performance of new GNSS satellite clocks. Doctor Dissertation. KIT Scientific Publishing, KarlsruheGoogle Scholar
- Montenbruck O, Steigenberger P, Schönemann E, Hauschild A, Hugentobler U, Dach R, Becker M (2011). Flight characterization of new generation GNSS satellite clocks. In: Proceedings ION GNSS 2011, Institute of Navigation, Portland OR, USA, 21–23 September, pp 2959–2969Google Scholar
- Senior K (2010) SVN62 Clock Analysis using IGS Data, IGSMAIL-6218. http://igscb.jpl.nasa.gov/pipermail/igsmail/2010/000051.html. Accessed 6 Aug 2010
- Shuai T, Xie Y (2016) The onboard passive hydrogen maser for navigation satellite. SCIENCE 68(5):11–15 in Chinese Google Scholar
- Svehla D (2010). Complete relativistic modelling of the GIOVE-B clock parameters and its impact on POD, track–track ambiguity resolution and precise timing. IGS Workshop 2010, Springer, NewcastleGoogle Scholar
- Uhlemann M, Gendt G, Ramatschi M, Deng Z (2015) GFZ global Multi-GNSS network and data processing results. In: Rizos C, Willis P (eds) IAG 150 Years. International Association of Geodesy Symposia, vol 143. Springer, Cham. https://doi.org/10.1007/1345_2015_120
- Wang H, Xie J, Zhuang J, Wang Z (2017) Performance analysis and progress of inter-satellite-link of Beidou system. In: Proceedings of ION GNSS 2017, Portland OR, USA, 25–29 Sept, pp 1178–1185Google Scholar