通过相位校准信号定标绝对链路时延方法及应用  

Method and Application of Measuring Absolute Link Delay by PCAL

作　　者：常捷 王锦清[1,3,4] 江永琛 舒逢春[1] Chang Jie;Wang Jinqing;Jiang Yongchen;Shu Fengchun(Shanghai Astronomical Observatory, Chinese Academy of Sciences, Shanghai 200030, China;University of Chinese Academy of Sciences, Beijing 100049, China;Key Laboratory of Radio Astronomy, Chinese Academy of Sciences, Nanjing 210033, China;Shanghai Key Laboratory of Space Navigation and Positioning Techniques, Shanghai 200030, China)

机构地区：[1]中国科学院上海天文台,上海200030 [2]中国科学院大学,北京100049 [3]中国科学院射电天文重点实验室,江苏南京210033 [4]上海市空间导航与定位技术重点实验室,上海200030

出　　处：《天文研究与技术》2022年第4期297-304,共8页Astronomical Research & Technology

基　　金：国家重点研发计划(2018YFA0404702);国家自然科学基金(11873015);中国科学院关键技术人才项目资助.

摘　　要：甚长基线干涉测量(Very Long Baseline Interferometry,VLBI)通过相位校准(Phase Calibration,PCAL)信号来校准链路时延。现有系统的相位校准信号只能获取链路时延的相对变化。面对UT1精准测量、台站钟差补偿、维护诊断和提高未来深空探测精度等需求,天线链路的绝对时延定标至关重要。在天线链路中,由于存在变频器等器件,测量绝对时延较为困难。利用梳状谱相位随频率线性变化的特点,提出了一种不需要参考变频器,采用相位校准信号定标绝对链路群时延的方法。同时,设计了一款用于台站快速诊断和绝对时延定标的轻量级相位校准提取软件,该软件目前已在调试工作中应用。Very long baseline interferometry(VLBI)uses phase calibration(PCAL)signal to calibrate link delay.However,the existing PCAL signal can only obtain the relative change of link delay.To meet the requirements of accurate measurement of absolute UT1,station clock error compensation,maintenance and diagnosis,and to improve the accuracy of deep space TT&C in the future,absolute link delay is necessary to know.In actual link,it is difficult to measure the absolute delay due to the existence of converter and other devices.This paper proposes a method to measure the absolute link delay using PCAL based on the linear variation of comb spectrum phase with frequency.At the same time,this paper designs a lightweight PCAL extraction software for fast diagnosis and absolute time delay measuring,which has been applied in practical work.

关 键 词：链路时延 甚长基线干涉测量 相位校准 模糊度 

分 类 号：P16[天文地球—天文学]