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

Abstract

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.

Keywords

deep space TT&C / VLBI / frequency stability / residual delay rate

References

[1] 吴伟仁,刘继忠,唐玉华,等. 中国探月工程[J]. 深空探测学报(中英文),2019,6(5):405-416
WU W R,LIU J Z,TANG Y H,et al. China lunar exploration program[J]. Journal of Deep Space Exploration,2019,6(5):405-416
[2] 洪晓瑜,张秀忠,郑为民,等. VLBI技术研究进展及在中国探月工程的应用[J]. 深空探测学报(中英文),2020,7(4):321-331
HONG X Y,ZHANG X Z,ZHENG W M,et al. Research progress of VLBI technology and application to China lunar exploration project[J]. Journal of Deep Space Exploration,2020,7(4):321-331
[3] 吴伟仁,李海涛,李赞,等. 中国深空测控网现状与展望[J]. 中国科学:信息科学,2020,50(1):93-114
WU W R,LI H T,LI Z,et al. Status and prospect of China’s deep space TT&C network[J]. SCIENTIA SINICA Informationis,2020,50(1):93-114
[4] NIELL A,BARRETT J,BURNS A,et al. Demonstration of a broadband very long baseline interferometer system:a new instrument for high-precision space geodesy[J]. Radio Science,2018,53(10):1269-1291
[5] 杨文哲，杨宏雷，赵环，等. 光纤时频传递技术进展[J]. 时间频率学报，2019（3）：214-223.
YANG W Z，YANG H L，ZHAO H，et al. Technical progress of fiber-based time and frequency transfer[J]. Journal of Time and Frequency，2019（3）：214-223.
[6] CALONICO D,BERTACCO E K,CALOSSO C E,et al. High-accuracy coherent optical frequency transfer over a doubled 642-km fiber link[J]. Applied Physics B,2014,117(3):979-986
[7] DROSTE S,OZIMEK F,UDEM T,et al. Optical-frequency transfer over a single-span 1 840 km fiber link[J]. Physical Review Letters,2013,111(11):110801
[8] 刘涛,刘杰,邓雪,等. 光纤时间频率信号传递研究[J]. 时间频率学报,2016,39(3):207-215
LIU T,LIU J,DENG X,et al. Research on fiber-based time and frequency transfer[J]. Journal of Time and Frequency,2016,39(3):207-215
[9] CHEN X,LU J,CUI Y,et al. Simultaneously precise frequency transfer and time synchronization using feed-forward compensation technique via 120 km fiber link[J]. Scientific Reports,2015(5):18343
[10] WANG B,GAO C,CHEN W L,et al. Precise and continuous time and frequency synchronisation at the 5×10^?19 accuracy level[J]. Scientific Reports,2012,2(2):556
[11] GAO C,WANG B,CHEN W L,et al. Fiber-based multiple-access ultrastable frequency dissemination[J]. Optics Letters,2012,37(22):4690-4692
[12] 王锦清,江永琛,苟伟,等. 地面稳相频标传输系统设计和测试[J]. 天文学报,2014(5):427-436
WANG J Q,JIANG Y C,GOU W,et al. Design and testing of a ground-based system for phase stabilized standard frequency transmission[J]. Acta Astronomica Sinica,2014(5):427-436
[13] 江永琛,王锦清,苟伟,等. 基于光纤传输的1.5 GHz信号的稳相系统设计与测试[J]. 时间频率学报,2017,40(3):137-145
JIANG Y C,WANG J Q,GOU W,et al. Design and test of a 1.5 GHz phase stabilization system based on optical fiber transmission[J]. Journal of Time and Frequency,2017,40(3):137-145
[14] YANG N,QIU Q,SU J,et al. Research on the temperature characteristics of optical fiber refractive index[J]. Optik,2014,125(19):5813-5815
[15] JIN L,ZHANG W,HAO Z,et al. An embedded FBG sensor for simultaneous measurement of stress and temperature[J]. IEEE Photonics Technology Letters,2005,18(1):154-156
[16] THOMPSON A R，MORAN J M，SWENSON G，et al. Interferometry and synthesis in radio astronomy[M]. Berlin：Springer，2017.
[17] TAKAHASHI F， KONDO T， TAKAHASHI Y， et al. Very long baseline interferometer[J]. Electronic Systems Magazine IEEE， 2002，17（8）： 43-44.
[18] 舒逢春. 人造卫星实时射电干涉测量方法研究[D]. 上海：中国科学院上海天文台，2008.
SHU F C. Study on the real time application of radio interferometry for satellite tracking[D]. Shanghai：Shanghai Astronomical Observatory，Chinese Academy of Sciences，2008.
[19] LITTLE A G. A phase-measuring scheme for a large radio telescope[J]. IEEE Transactions on Antennas and Propagation,1969,17(5):547-550
[20] SIGMAN E H. Phase calibration generator[C]//The Telecommunications and Data Acquisition Report. Pasadena：Jet Propulsion Laboratory，1988：89-104.
[21] MCCOOL R，BENTLEY M，GARRINGTON S，et al. Phase transfer for radio astronomy interferometers，over installed fiber networks，using a round-trip correction system[C]//Annual Precise Time and Time Interval Systems and Applications Meeting. Reston：Naval Observatory，2008：107-116.
[22] PRIMAS L E，LUTES G F，SYDNOR R L. Stabilized fiber optic frequency distribution system[C]// Telecommunications and Data Acquisition Progress Report. Pasadena：Jet Propulsion Laboratory，1989：88-97.
[23] SHILLUE B. ALMA LO distribution round trip phase correction[EB/OL]. （2002-11-14）[2021-06-21]. http://www.alma.nrao.edu/memos/html-memos/alma443/memo443.pdf.
[24] OH H J，KONDO T，LEE J，et al. Round-trip system available to measure path length variation in korea VLBI system for geodesy[C]//Proceedings from the 2010 General Meeting. [S. l.]：International VLBI Service for Geodesy and Astronomy，2010：449-453.
[25] NAPIER P J,THOMPSON A R,EKERS R D. The very large array:design and performance of a modern synthesis radio telescope[J]. Proceedings of the IEEE,1983,71(11):1295-1320
[26] DENG T，MA M，LIU Q，et al. High-precision carrier tracking algorithm for extremely weak and high-dynamic signals[J]. Radio Science，2021，56（5）：e2021RS007277.