Abstract:To build GPS carrier phase time and frequency dissemination system and implement GPS carrier phase time and frequency dissemination preliminarily,two different time and frequency dissemination experiments including zero baseline and long baseline experiments with the same references and/or the different references were conducted using GPS carrier phase rather than PN codes,in the GPS carrier phase time and frequency transfer system at NIM.In the data processing, the professional GPS process software package partly and the self-developed software were used to process the GPS carrier phase observations at 30-second intervals and the relative clock estimates at 1-minute intervals was analyzed.The results of the zero baseline experiments show that GPS carrier phase time and frequency dissemination has a stability of about 100 picoseconds,which translates into a frequency uncertainty of less than two parts in 1015 for a sampling time of one day in the zero baseline conditions; from the Allan deviations in the experiments,it is shown that GPS carrier time and frequency dissemination has a certain ability of measuring the frequency stability remotely for some atomic clocks including some cesium clocks.But in the long baseline experiments,time and frequency dissemination using GPS carrier phase has a stability of about 900 picoseconds,which translates into a frequency uncertainty of about two parts in 1014 for a sampling time of one day.
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