The research project started in Nov., 2003 was scheduled to be completed at the end of 2005. It aims at setting up a preliminary network real-time JATC system before the end of 2005 through taking full advantage of existing domestic atomic clock resources and using part of time labs qualified for the joint atomic time in the Chinese Academy of Sciences (CAS) as the main labs, in a bid to increase significantly the stability of independent regional (national) atomic time TA (JATC) and the accuracy of UTC (JATC) relative to the international standard time (UTC: Universal Time Coordinator). At the same time, the largely intensified reliability of the system lays a foundation for establishing a final unified Chinese UTC, and sets a stage for the frequency standard’s test and evaluation of each domestic lab.

The project experienced a smooth progress in 2004. The single- and double-frequency GPS common-view receivers, important time comparison equipment required by the project, were designed and formed independently, and 6 single-frequency receivers in total came into being at the beginning of Oct., reaching the technical indexes through test; 6 double-frequency GPS common-view receivers would be finished in Nov. The design and sample of remote data transmission system based on telephone have been finished; computing software for the GPS common-view remote time transmission has been programmed; monitoring software of UTC (JATC) has been programmed and under the trial-run; the automatic operation of time-keeping system conducted to implement the plan of joint automatic time is coming to an end, and hardware connection and software programming for the “parameter acquisition and data analysis & processing system inside the Sigma-tau hydrogen atomic clock” is completed.