Research and application of multi-channel GPS Common-view receiver in NIM

GPS Common-view is a very important and widely used technology for time and frequency transfer. The multi-channel GPS common-view receiver has been developed successfully in NIM China. This receiver is composed of a VP ONCORE engine made by Motorola company and a high precision time interval counter (TIC) developed by our staff. The resolution of the TIC is 50ps. The software is accordant with standardization guide for data process software of GPS common-view method. Compared with single channel receiver, this multi-channel receiver has more friendly interface, it is more convenient to operate and also has a stronger ability to analyze and process data. The experimental result shows the time transfer uncertainty of the multi-channel GPS receiver is less than 4ns in the condition of common-clock on zero base line. As for the complicated circumstance in NIM China, Some experiments have been done in order to decrease the effect of the circumstance. The multi-channel receiver has been used in the International Atomic Time Comparison System of NIM China, and also been used in domestic remote time and frequency calibration service. Some detail will be described in this paper.