Abstract:In order to meet the needs of remote time users for standard time UTC (NTSC) nanosecond distribution, a standard time remote reproduction system has been established. The single-reference terminal service model currently used in the system has certain risks. If the single receiver fails, it will affect the accuracy of the resulting deviation between local time and satellite clock (i.e., the time difference between satellite time and local time).To solve the above problems, this paper proposes a method based on robust estimation for GNSS common-view multi-reference stations to fuse the time difference between satellite time and local time. In this method, the median absolute deviation (MAD) is used to detect the outliers of the time difference between satellite time and local time data, and the robust estimation method of IGG III. equivalent weight function is used to fuse the above data of multiple stations, to output a set of stable reference station reference values. Comparing the outlier detection performance of the MAD method and the 3.Sigma method through the Matlab simulation, the MAD method is more applicable for the time difference between satellite time and local time data of the reference stations. At the same time, the fusion method based on robust estimation is compared with the equal-weight fusion method, the standard deviation of the fusion data of the former is 0.11~6.65 ns lower than that of the latter, which improves the stability of the system.