Abstract:

 According to the characteristics of the space station orbit, the effect of space station orbit error on the one way and common-view time comparison is analyzed both in theory and simulation firstly. The research result shows that the effect of orbit error on time comparison is about several hundred picoseconds, and it is the main error source that restricts the time comparison accuracy to be improved. Then, an appropriate orbit error calibrating method that is based on the position relationship between the space station and two ground stations is introduced. Additionally, the high stability of the space and ground atomic clocks is advantaged to model and extrapolate the space-ground clock bias. The geometric position relationship and the modeling and extrapolating of the space-ground clock bias are combined together to solve the problem of orbit error. Finally, some simulation experiments are done to validate the proposed method. The experiment results show that the method is effective and the time comparison accuracy is great improved to be several ten picoseconds, the baseline is up to the magnitude of thousand kilometers.

Key words: Space station, Time comparison, Common-view, Orbit error, Clock bias modeling