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Giga-bit Geodesy e-VLBI Using the Super-Sinet

Giga-bit Geodesy e-VLBI Using the Super-Sinet. Hiroshi Takaba (Gifu University, Japan). Collaborators. N. Kawaguchi, Y. Kono, H. Suda (NAOJ) K. Takashima, M. Ishimoto, M. Machida (GSI) Y. Koyama, T. Kondo, M. Sekido (NICT) H. Takeuchi (ISAS) N. Nakai (Tsukuba Univ.)

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Giga-bit Geodesy e-VLBI Using the Super-Sinet

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  1. Giga-bit Geodesy e-VLBI Using the Super-Sinet Hiroshi Takaba (Gifu University, Japan)

  2. Collaborators N. Kawaguchi, Y. Kono, H. Suda (NAOJ) K. Takashima, M. Ishimoto, M. Machida (GSI) Y. Koyama, T. Kondo, M. Sekido (NICT) H. Takeuchi (ISAS) N. Nakai (Tsukuba Univ.) H. Sudou, K. Wakamatsu (Gifu Univ.) and Japanese e-VLBI network group

  3. 1) Giga-bit Geodesy e-VLBI by using the Super-Sinet between GSI Tsukuba 32m and Gifu 11m (311km apart) 2) Recent progress of the Japanese Giga-bit e-VLBI Network

  4. What is Super-Sinet? Super-Sinet is the 10Gbps class dedicated network operated by Ministry of Edu. & Sci. for 5 research regions, 1) High Energy Physics & Nuclear Fusion 2) Space Science & Astronomy 3) Bio-informatics 4) Distributed computing (GRID) 5) Nano-technology connects some National Institutes & Universities

  5. Super-sinet Sinet

  6. Last 1-mile to the Super-Sinet We have to prepare the access fibers to the node! • A CATV company provided fibers from High Energy Laboratory to GSI 32m at Tsukuba (about 10 km) with reasonable cost • Gifu Prefecture operates Information Super-Highway, we borrowed two dark fibers from Fusion Research Laboratory to Gifu University (about 100km) free, we obtain two 2.4Gbps links by the WDM technique.

  7. WDM(Wavelength Division Multiplexer) transceiver modules at a Gifu Prefecture’s Information Super Highway link station. We only use two wavelengths, up to 8links (OC48 or GbE) extensions are possible

  8. Properties of our Giga-bit Geodesy e-VLBI System • Dedicated Network - 2.4Gbps (OC48) x 2ATM links - By using up and down links, we realized 4Gbps, 8Gbps will be possible! • Real-time correlation , no recording for the raw data - XF type hardware correlator with 256lags - Fringes are found within 5min. and stable for 24hs. • Simultaneous observations with K5/Giga-bit system - To check repeatability, reliability and for debugging

  9. Giga-bit Real-time e-VLBI instruments at Gifu University Correlator Control Computer A/D Converter (ADS1000) 2 channels XF type Correlator For 3 Baselines 256lags Optical Transceiver 2.4Gbps x2 links With GbE

  10. Giga-bit Geodesye-VLBI using the Super-Sinet Gifu Univ. Tsukuba X 11m Telescope 32m Telescope S X S X Real time Correlator A/D converter 2Gbps×2ch A/D converter 2Gbps×2ch S Optical Transceiver OC48(2.4Gbps)×２ Optical Transceiver OC48(2.4Gbps)×２ Tsukuba CATV 100km Gifu Prefecture’s Information Super Highway 10km WDM WDM Real time Correlator Super- Sinet Super- Sinet Super-Sinet OC48(2.4Gbps) Super-Sinet OC48(2.4Gbps) Super-Sinet OC48(2.4Gbps) Fusion Research Lab. High Energy Lab. 500km? NAOJ（Mitaka City） 100km?

  11. Real Time e-VLBI S band Processes at Mitaka X band Processes at Gifu Display the fringe pictures every 1 seconds Gifu Correlator S Mitaka Correlator X

  12. Results of Geodesy VLBI with K4/K5 and e-VLBI Results of the K4/K5 and e-VLBI coincide within 3mm !

  13. X Band 2ch extension （JD0608: Aug. 2006） Gifu Correlator X high 8180-8680MHz Mitaka Correlator X low 7780-8280MHz

  14. Some Problems • Jitter of the sampler about 20ps for about 100 seconds integration (Koyama-san said it should be within several ps) • 1 sec. slip of the Correlator outputs It sometimes happens for ch1 and ch3 correlators • Systematic drifts of the delay time compared with K4/K5 and Giga-bit e-VLBI systems 　　　 ～ 1ns for 24hours experiment

  15. Differences of the delay time for K4 and Giga-bit e-VLBI Xband pico-seconds 1nsｓ Obs. #

  16. K5 and Giga-bit e-VLBI Almost same as K4 - Giga-bit e-VLBI! Xband pico-seconds

  17. K4 and K5 No large drift！ Xband pico-seconds

  18. Xband Sband

  19. Why Drift exists? • K4 and K5 uses band width synthesis technique • Giga-bit e-VLBI uses all IF bands and no-band width synthesis • Some drifts which can be canceled by the band synthesis technique, i.e. cable length change by the temperature, are seen?

  20. Next Plan, 22GHz e-VLBI • Install 22GHz band receivers for both Gifu 11m (November 2006) Tsukuba 32m (Nov.2006? by Tsukuba Univ.) • 8Gbps(4ch) e-VLBI Oct. 2007 Move a 3stn correlator from Mitaka to Tsukuba Add 4 more ADS1000 samplers (or 2 more ADS3000?) Make 4ch down-converters • Apply 32GHz sampler to 22GHz receivers to make narrow beam Water Vapor Radiometers (2008?)

  21. 8Gbps e-VLBI using the Super-Sinet Gifu Univ. Tsukuba 11m Telescope 32m Telescope Real time Correlator Real time Correlator A/D converter 2Gbps×4ch A/D converter 2Gbps×4ch Optical Transceiver OC48(2.4Gbps)×２ Optical Transceiver OC48(2.4Gbps)×２ Real time Correlator Real time Correlator Super- Sinet Super- Sinet Super-Sinet OC48(2.4Gbps) Super-Sinet OC48(2.4Gbps) Super-Sinet OC48(2.4Gbps) Fusion Research Lab. High Energy Lab. NAOJ（Mitaka City）

  22. Recent Progress of the Japanese Giga-bit e-VLBI Network • Connected two Stations Nobeyama 45m (Dec. 2005) 22GHz/43GHz Yamaguchi 32m (April 2006) 8GHz => 2/8/22/43GHz, 55-800km extension • New FX correlator with 16K lags completed • InP HBT sampler with 32GHz/3bit testing

  23. Japanese Giga-bit e-VLBI Network 4.8 Gbps by Super-Sinet 2.4 Gbps by NTT or JGN2 Future Plan ISAS Usuda64m HokkaidoUniv.11m NAO Mizusawa20m NAO Nobeyama45m GSI Tsukuba32m NAO HQ(Mitaka) NAO Yamaguchi32m Gifu Univ.11m NAO Kagoshima20m NICT Kashima34m

  24. First Fringes detected between Yamaguchi 32m and Tsukuba 32m April 23, 2006 3C84 in 8-GHz band New FX type correlator with 16K lags expands fringe search windows from 256ns to 16μs ! -14 μs

  25. InP HBT AD Converter DMX A 32-GHz signal was successfully digitized with 3 bits. Ask Kawaguchi-san for more details RF Signal DMX ADC

  26. Imaging trial with fiber connected stations (8GHz band) 3C66B 1928+738 Four station image (U64-T32-K34-G11) 2005 Five station image Coming soon! Aug. 2006 Three station image (U64-T32-G11) 2004

  27. Future Plan • Connect VERA telescopes ～2011 • Apply 22GHz/43GHz ultra-wide band geodesy e-VLBI to determine telescope positions within 1mm • 2Beam+High speed switching e-VLBI observations for phase referencing => 10μas astrometry & sub-millimeter geodesy Also, connect KVN, China & Australian telescopes to make Asia Pacific e-VLBI network!

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