Analysis of correlation between clock offset and environmental temperatures of stations for TWSTFT

 CAO Fen^1,2,3, YANG Xu-hai^1,2, LI Zhi-gang^1,2,

YANG Ying^1,2,3, SUN Bao-qi^1,2, FENG Chu-gang^1,4

1. National Time Service Centre, Chinese Academy of Sciences, Xi′an 710600, China;

2. Key Laboratory of Precision Navigation and Timing Technology, National Time Service Center,

Chinese Academy of Sciences, Xi′an 710600, China;

3. Graduate University of Chinese Academy of Sciences, Beijing 100039, China;

4. Shanghai Astronomical Observatory of Chinese Academy of Sciences, Shanghai 200030, China

Abstract: For analyzing the correlation between the clock offset and the environmental temperatures of stations for TWSTFT(two-way satellite time frequency transfer), the correlation coefficients between the clock offset and the environmental temperatures of stations for TWSTFT are calculated and analyzed, and a fitted function that relates the residual of clock offset with the environmental temperatures of stations is constructed by using the observation data of TWSTFT (in C-band, for Shanghai-Xi′an link, during the June of 2005). The results show that the environmental temperatures obviously affect the residuals of clock offset. The residuals of clock offset are revised with the fitted function and the RMS(root-mean-square) values of the revised residuals of clock offset reduce by 25%~50%. The observation devices should be kept in an environment with constant temperature, which is of special significance to the time synchronization between the stations for TWSTFT in C-band.

Key words: environmental temperature; TWSTFT; residual of clock offset; correlation coefficient