Proposal for a realtime Einstein-synchronization-defined satellite virtual clock  

作　　者：严晨皓 汤雪逸 王时光 孟李皎悦 孙海媛 何奕彬 王力军 Chenhao Yan;Xueyi Tang;Shiguang Wang;Lijiaoyue Meng;Haiyuan Sun;Yibin He;Lijun Wang(Department of Precision Instrument,Tsinghua University,Beijing 100091,China;Department of Physics,Tsinghua University,Beijing 100091,China)

机构地区：[1]Department of Precision Instrument,Tsinghua University,Beijing 100091,China [2]Department of Physics,Tsinghua University,Beijing 100091,China

出　　处：《Chinese Physics B》2024年第7期268-276,共9页中国物理B（英文版）

基　　金：supported by the National Key Research and Development Program of China(Grant No.2021YFA1402100)。

摘　　要：Realization of high performance satellite onboard clock is vital for various positioning, navigation, and timing applications. For further improvement of the synchronization-based satellite time and frequency references, we propose a geosynchronous(GEO) satellite virtual clock concept based on ground–satellite synchronization and present a beacon transponder structure for its implementation(scheduled for launch in 2025), which does not require atomic clocks to be mounted on the satellite. Its high performance relies only on minor modifications to the existing transponder structure of GEO satellites. We carefully model the carrier phase link and analyze the factors causing link asymmetry within the special relativity. Considering that performance of such synchronization-based satellite clocks is primarily limited by the link's random phase noise, which cannot be adequately modeled, we design a closed-loop experiment based on commercial GEO satellites for pre-evaluation. This experiment aims at extracting the zero-means random part of the ground-satellite Ku-band carrier phase via a feedback loop. Ultimately, we obtain a 1σ value of 0.633 ps(two-way link), following the Gaussian distribution. From this result, we conclude that the proposed real-time Einstein-synchronization-defined satellite virtual clock can achieve picosecond-level replication of onboard time and frequency.

关 键 词：Einstein synchronization satellite virtual clock geosynchronous satellite carrier phase 

分 类 号：P228[天文地球—大地测量学与测量工程]