Analysis of GPS AV time comparison between NTSC and PTB

Analysis of GPS AV time comparison between NTSC and PTB

LI Yong-ping^1,2, Qu Li-li^1,2

(1. National Time Service Center, Chinese Academy of Sciences, Xi′an 710600, China;

2. Key Laboratory of Time and Frequency Primary Standards, National Time Service Center,

Chinese Academy of Sciences, Xi′an 710600, China)

Abstract: Based on the measurements obtained with a GPS single-frequency receiver and a GPS dual-frequency receiver, which are two different types of observation equipment developed at NTSC(national time service center, chinese academy of sciences), the GPS AV(all-in-view) comparison and calculation for NTSC-PTB(physikalisch-technische bundesanstalt(Germany)) link were conducted. The results were analysed and the uncertainty is shown to be consistent with that published by BIPM, thus confirming that the two types of GPS receiver developed at NTSC have reached the international level. The precision of time comparison can be expected to be improved by 50% for NTSC, if the time-delay of the GPS dual-frequency receiver can be calibrated and AV(P3) is adopted.