1/16 Entrusted by BSMI, MOEA, Taiwan 2014 Status Report of National Time and Frequency Standard Laboratory, TL, Taiwan Time Transfer Group Time Keeping & Dissem. Group H. T. Lin F. D. Chu W. H. Tseng Y. J. Huang C. S. Liao S. Y. Lin C. C. Lin P. C. Chang J. L. Wang Z. J. Huang
2/16 Introduction Harmonized with international standard (12 Cs clocks & 4 H-masers) TAI Time Transfer Met industrial and public requirement T/F researches UTC Geoscience Power Comp Manufactory Cal. Labs. GPS remote calibration T/F calibration Speaking Clock T/F Dissemination ACTS servi ces Lease-line T/F LF Station (Planning) NTP (Internet) 3C equipment Daily life Wall clock watch alarm clock Transportation Airports Telecom. E-commer. TSA MID
3/16 Clocks and Time Scales Cesium clocks ensemble: Symmetricom 5071A (high performance tube) 13 -Running: 12 clocks -Under fixing: 1 clock TA(TL) is generated by 12 Cs-Clocks Active H-masers: Kvarz CH1-75 2(without CAT) imaser-3000 (with CAT) Microsemi MHM-2010 (operated on May 2014) Time Scale: imaser 3000 5 MHz AOG-110 Steered base on UTC and TA(TL) UTC(TL)
4/16 UTC-UTC(TL) 10 ns -20ns 40 days
Microwave Frequency Measurement Capability Current microwave frequency measurement capability at TL using a down-convert technique : 300 MHz~26.5 GHz In 2014, a active microwave amplifier doubler was successfully used to upgrade capability of the system from 26.5 GHz to 40 GHz When in a common clock test, frequency stability of the system is about 2.0E-12 (carrier frequency 40 GHz ; τ =1 sec) Fig 1. Diagram of microwave frequency measurement at TL using a down-convert technique 5/2 Fig 2. A active microwave doubler and a power supply 5/16
TWSTFT Links Telecommunication Laboratories 6/16
Earth Stations TL04, 2.4 m Eutelsat 172A; Asia-USNO Link TL03, 1.8 m Eutelsat 172A; R/D &backup station TL01, 2.4 m Eutelsat 172A; Asia-pacific Link Cable Tray TL02, 2.4 m AM2; EuroAsia TAI Link Telecommunication Laboratories 7/16
8/16 Common-Clock TWSTFT Test 2.4m, TL04 Eutelsat 172A 1.8m, TL03 2.5Mcps 70.02MHz P/S P/S 2.5Mcps 69.98MHz TX RX ADC ADC RX TX SATRE #73 VSSP32 UTC(TL) T4Science imaser 3000 USRP N210 SATRE #63 ADC is used to implement our technique on software-defined receiver (SDR) for TWSTFT
Common Clock Difference (ns) Common-Clock TWSTFT Results 1 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 SATRE Modem SDR 0 0 2 4 6 8 10 12 14 Elapsed Time since MJD 56636 (2013/12/10) SATRE Modem offset: +0.55 ns SDR offset: + 0.2 ns 9 9/16
10/16 T/F Synchronization via Optical Network Surveying the requirements of Telecom synchronization Study on Asymmetry Compensation for Accurate Time/Phase Transport Over Optical Transport Network
Ionospheric Electrodynamics Effects on TWSTFT 11/16 1. The TWSTFT time differences often appear local minimum during 18-21 UTC (02-05 LST at TL), as indicated by blue arrows. 2. This result is much clearer when the counterpart at higher latitude than at lower latitude. 3. The predawn local minimum in TWSTFT time difference pattern maybe results from ionospheric neutral winds.
12/16 A Robust Speaking Clock Design Added a protecting sub-system A multi-time selecting system is against link failure. A back up system is against speaking clock failure. Added a monitoring sub-system measure the input and output time error. Sending out a message alerts operators if an error happens.
13/16 Automatic Adjustment of a Leap Second IEEE-1344 protocol extends to cover leap second information for IRIG-B code. A FPGA-based IRIG-B module was designed to meet the adjustment need.
14/16 2014 IEEE IFCS & ATF meeting IFCS 2014 was successfully held at the Taipei International Convention Center, May 19-22, 2014. The ATF 2014 workshop is a technical co-sponsor of the symposium. TL supports 3 Technical Program Committee members, and 3 Session Chairs.
15/16 Recent 3 years 近三年計畫產出及研發成果 本實驗室對國際原子時 (TAI) 貢獻之權重, 在全球實驗室間名列前茅 Published over 40 international papers, 含 SCI 期刊論文 13 篇 研討會論文 25 篇 As referees for more than 8 SCI journals NTP service: ~300 millions/day; 117speaking clock service : 120 thousands/day International activities 與日本 NICT 合作, 完成全球首例之衛星雙向傳時 DPN 國際比對實驗 2012 首度成功爭取 APMP TC initiative 計畫, 於紐西蘭舉辦 GNSS 校正展示活動 完成舉辦 ATF 2013 workshop 研討會 - 與 AP-RASC 13 合辦, 十餘個國家的 60 多位專家與會 2013.09 完成舉辦 CCTF TWSTFT 工作小組年度會議 2013.10~2014/01 參與完成 BIPM GNSS 鏈路校正先鋒計畫之量測實驗 2014.05 完成與 2014 IEEE IFCS 研討會聯合舉辦之 ATF 2014 workshop 國際會議, 此為 IEEE IFCS 會議首度在亞洲舉辦, 亦為 APMP 與 IEEE 聯合舉辦活動之首例 Awards 同仁擔任 APMP TCTF( 時頻技術委員會 ) 主席 並擔任國際同儕評鑑之評審員 同仁應邀加入 CCTF( 國際時頻技術諮詢委員會 ) 之 ATFT GNSS 等工作小組 同仁連續榮獲內政部役政署 2011 及 2012 年度 績優研發替代役役男 同仁榮獲 2012 年度之中華民國計量工程師獎 同仁論文榮獲 the 2014 NCSLI Measure Editor s Choice Award
Future Researches keep on studying SDR & CP TWSTFT setup T/F optical laboratory search for synchronization applications such as power smart grid + telecom NGN + cloud network + Telecommunication Laboratories 16/16