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| 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 |
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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.
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Received: 01 December 2020
Published: 08 April 2022
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2022, Vol. 43 
