High Accurate Time System of the Low Latitude Meridian Circle

In order to obtain the high accurate time sig nal for the Low La ti tude Medrian Circle(LLMC), a new GPS accurate time system is developed which include GPS, 1MC frequency source and self-made clock system. The second signal of GPS is synchornously used in the clock system and information can be collected by a computer automa tically. The difficulty of the cancellation of the time keeper can be overcomed by using this system. All the hardw are constitutions and software prog ramming of this time system are introduced in this paper. This system has been used in the debuging and it may be used in other observation occasions.