VLBI深空测控的单光纤多测站频率传递系统设计  

Design of Multi-Station Frequency Transfer System for VLBI Deep Space TT&C Based on Single Fiber

作　　者：常捷 王锦清[1,3,4] 舒逢春 江永琛[1] CHANG Jie;WANG Jinqing;SHU Fengchun;JIANG Yongchen(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 210008,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,南京210008 [4]上海市空间导航与定位技术重点实验室,上海200030

出　　处：《深空探测学报（中英文）》2021年第6期600-607,共8页Journal Of Deep Space Exploration

基　　金：国家自然科学基金资助基于可变形副面的射电望远镜补偿算法与技术研究项目(11873015);国家重点研发计划资助(2021YFC2203501,2018YFA0404702);中国科学院关键技术人才项目资助。

摘　　要：月球与行星探测中,甚长基线干涉(Very Long Baseline Interferometry,VLBI)技术为实现高精度测角,需要稳定的频率基准。设计了一种仅用单套设备、单根光纤实现多用户传输的频率传递系统。该系统通过混频器与环形器等组合实现无锁相环的全自动快速往返校正,以补偿频率标准信号传输中的相位漂移,为测站提供稳定的频率基准,降低测量误差。该系统兼容电缆和光纤传输介质,兼具实时补偿和事后补偿模式,能满足有多天线的测站的需求。经地面验证,实时补偿模式天稳达10−17量级,并有能力升级到天稳10−19量级;事后补偿模式天稳达10−18量级。经VLBI射电源观测和对“天问一号”火星探测器的观测验证,两站钟速差降至10−14量级,能满足为多天线或多测站提供稳定本振进行VLBI观测的需求。目前该系统已在VLBI深空测控和地球定向参数(Earth Orientation Parameters,EOP)测量中应用,表现出较高可靠性。Very Long Baseline Interferometry(VLBI)technology requires a stable frequency datum for high-precision angular measurement in lunar and planetary explorations.A multi-user frequency transfer system for VLBI stations using only single optical fiber is designed.It realizes full-automatic fast round-trip correction phase loop without PLLs,using mixer and circulator to deliver stable standard frequency signal to antennas.The system has both real-time compensation mode and post compensation mode,and supports multiple receivers to meet the needs of VLBI stations with multiple radio telescopes.The practical results show that the frequency stability reach 10−17/day level within the ability to the 10−19 in real-time compensation mode and 10−18/day in post compensation mode.VLBI observation for radio source and HX-1 shows that the clock rate difference is reduced to 10−14 level,which can effectively reduce errors.The requirements that multiple antennas share the same oscillator has been fulfilled.At present,the system has been applied in VLBI deep space TT&C and EOP observation,maintaining high reliability.

关 键 词：深空测控 甚长基线干涉测量 频率稳定度 残余时延率 

分 类 号：V556.3[航空宇航科学与技术—人机与环境工程]