Study on Modified CGGTTS Algorithm Based on Real-time Performance and Data Utilization Rate
HAO Shuang-yu1,2,3,BI Hong-jun1,LIANG Kun1,3
1. School of Electronics and Information Engineering, Beijing Jiaotong University,Beijing 100044, China
2. Zhejiang Institute of Medical Device Testing, Hangzhou, Zhejiang 310018, China
3. Division of Time and Frequency Metrology, National Institute of Metrology, Beijing 100029, China
Abstract：To avoid waste of measurement data, the GNSS time-frequency transfer data standard format CGGTTS has been improved. The improvement mainly includes: using all the measurement data in the data period to calculate the time difference values to improve the utilization rate of the measurement data. At the same time, in order to meet the higher requirements of time transfer users for real-time data, the CGGTTS data period is shortened to improve the performance of real-time. The experimental results show that when the data usage rate is increased to 100%, the noise of the comparison results can be reduced, and the noise performance can be improved by up to 6%. After shortening the data interval to 5 minutes, the real-time performance of the data is increased to 69%, and the noise performance deteriorates by more than 17%. Analyze the real-time performance, standard deviation, data volume, and calculation volume of files at different intervals, and it is obtained that when the data interval is between 8 and 13 minutes, the improved CGGTTS algorithm keeps the noise level of the common clock difference experiments at (0.70～0.80)ns, and the noise level of the long baseline experiments at (0.75～0.83)ns, which is a compromise choice.
郝爽雨,毕红军,梁坤. 基于实时性和数据使用率改进的CGGTTS算法研究[J]. 计量学报, 2022, 43(4): 547-553.
HAO Shuang-yu,BI Hong-jun,LIANG Kun. Study on Modified CGGTTS Algorithm Based on Real-time Performance and Data Utilization Rate. Acta Metrologica Sinica, 2022, 43(4): 547-553.
［1］ Lopez O, Kanj A, Pottie P E, et al. Simultaneous remote transfer of accurate timing and optical frequency over a public fiber network［J］. Applied Physics B, 2013, 110(1): 3-6.
［2］ Liang K, Zhang A, Yang Z, et al. Preliminary time transfer through optical fiber at NIM［C］// 2015 Joint Conference of the IEEE International Frequency Control Symposium & the European Frequency and Time Forum (FCS), 2015.
［3］ Jiang Z. Towards a TWSTFT network time transfer［J］. Metrologia, 2008, 45(6): S6.
［4］ 广伟. GPS PPP时间传递技术研究［D］. 西安: 中国科学院研究生院(国家授时中心) , 2012.
［5］ 张鹏飞, 涂锐, 广伟, 等. BDS-3时间频率传递方法及其性能分析［J］. 导航定位与授时, 2020 (5): 58-64.
Zhang P F, Tu R, Guang W, et al. BDS-3 Time Frequency Transfer Method and Performance Analysis［J］. Navigation Positioning and Timing, 2020 (5): 58-64.
［6］ Allan D W, Weiss M A. Accurate Time and Frequency Transfer During Common-View of a GPS Satellite［C］// Symposium on Frequency Control, 2005.
［7］ Harmegnies A, Defraigne P, Petit G. Combining GPS and GLONASS in all-in-view for time transfer［J］. Metrologia, 2013, 50(3): 277-287.
［8］ 高小珣, 高源, 张越, 等. GPS共视法远距离时间频率传递技术研究［J］. 计量学报, 2008, 29(1): 80-83.
Gao X X, Gao Y, Zhang Y, et al. GPS Common View Method for Remote Time and Frequency Transfer ［J］. Acta Metrologica Sinica, 2008, 29(1): 80-23.
［9］ Allan D W, Thomas C. Technical directives for standardization of GPS time receiver software［J］. Metrologia, 1994, 31(1): 69-79.
［10］ Lewandowski W, Azoubib J, Gevorkyan A, et al. A Contribution to the Standardization of GPS and GLONASS Time Transfers［C］// PTTI, Virgiuia, 1996.
［11］ Defraigne P, Petit G. CGGTTS-Version 2E: an extended standard for GNSS Time Transfer［J］. Metrologia, 2015, 52(6): G1.
［12］ Defraigne P, Verhasselt K. Multi-GNSS time transfer with CGGTTS-V2E［C］// 2018 European Frequency and Time Forum (EFTF), 2018.
［13］ Liu X, Zhao D L, Liu J L. BDS Common-View Method Based on CGGTTS V2E Standard［C］// Proceedings of 2018 International Conference on Computer Science, Electronics and Communication Engineering(CSECE2018), Wuhan, Hubei, China, 2018.
［14］ Jiang Z, Lewandowski W. Some remarks on the CCTF CGGTTS format［C］// IEEE 2011 Joint conference of the IEEE International Frequency Control and the European Frequency and Time Forum (FCS), San Francisco, CA, USA, 2011.
［15］ 张越, 高小珣. GPS共视法定时参数的研究［J］. 计量学报, 2004,25(2): 167-170.
Zhang Y, Gao X X. Research on Timing Parameters for GPS Common-view Method［J］. Acta Metrologica Sinica, 2004,25(2): 167-170.
［16］ 梁坤, 王伟波, 宁大愚, 等. GPS载波相位时间频率传递的研究［J］. 计量学报, 2010, 31(1): 71-76.
Liang K, Wang W B, Ning D Y, et al. Study on GPS Carrier Phase Time Frequency Dissemination［J］. Acta Metrologica Sinica, 2010, 31(1): 71-76.
2022, Vol. 43 
