Research on BD Nanosecond One-Way Timing Method

Abstract

Different from other GNSS navigation systems, the constellation of BD navigation system consists of GEO, MEO, and IGSO satellites which is the characteristic of BD. The altitude of GEO orbit is higher than that of MEO. Therefore, the ephemeris and ionosphere delay errors are more dependent in the paths from GEO satellites to two users involved in time comparison. Therefore, the results of common view time transfer based on GEO satellites are better than that of MEO. A method of changing the generation of UTC time parameters is proposed which makes full use of the advantages of GEO satellites in time transfer. The time difference between system time of navigation system and UTC(K) is monitored by user terminal which referenced with a ultrastable frequency signal. The UTC time parameters are generated based on these time differences. Users with the new UTC time parameters not only can get the time difference between their local time and UTC(K), but also can farther eliminate the errors in one-way timing method. Without aggravating the burden of users, the precision of this method is equivalent to that of common view time transfer which is superior to the existed GPS and BD one-way timing method.