The current status of K5 eVLBI intensive session Takashima, Kazuhiro; Machida,Morito; Fujisaku, Junichi; Kokado, Kensuke; Shigematsu, Hiromi Geographical survey institute, JAPAN
TOPIC 1. What is intensive session ? 2. System components 1.K5 recording system 2.K5 correlator system 3. eVLBI data transfer 4. Contribution to “Deep Impact Mission” 5. Results of Intensive session
IVS intensive session Monitoring the Rotation of the Earth (UT1) Leap second ( ) Leap second ( ) Leap second ( ) ・ The Earth rotation speed is not constant, disturbed by various dynamic phenomena. ・ VLBI is one of few techniques that can monitor the earth’s rotation.
IVS-INT1 and IVS-INT2 The 1 hour-long 1-baseline intensive sessions for UT1 measurement daily. Monday through Friday Mark 5 is used on the Kokee- Wettzell baseline, and on Saturday and Sunday Mark5/K5 is used on the Wettzell-Tsukuba baseline. SessionDaysBaselineCorrelator INT1Mon-FriWz-KkWACO Mark5 INT2Sat-SunWz-TsGSI K5 eVLBI
Number of INT session K5 K4 Mark*
System component (recording) Reference signal distributor 16ch video amps K5PC Disk alley(SATA disk) Mark5 Wettzell K5 Tsukuba IVS-INT2
hard disk Data server Data server Data server Data server correlator Current form of K5/VSSP at correlator side Current form of K5/VSSP at correlator side Management computer correlator Correlation servers (with 3GHz Intel Xeon dual CPUs) data servers System component K5 correlator Gb-E
System component K5 correlator Optical network K5 PC cluster correlator Data transfer
GSI Correlator downloads Mark5 data from Wz. convert the format from Mark5 to K5 simultaneously. automatic procedures 50Gbyte ncftp Auto-script friendly resume available
gemnet GEANT 2 Super-SINET X-WIN Regensburg Tsukuba Wettzell traceroute to Wettzell Station ( ), 30 hops max, 38 byte packets 1.tsukuba.gemnet.net ( ) ms 2.mecl.gemnet.net ( ) ms 3 nii-IX1-P3-0.sinet.ad.jp ( ) ms 4 NYC-gate1-P3-0.sinet.ad.jp ( ) ms 5 sinet.ny1.ny.geant.net ( ) ms 6 so rt1.ams.nl.geant2.net ( ) ms 7 so rt1.fra.de.geant2.net ( ) ms 8 dfn-gw.rt1.fra.de.geant2.net ( ) ms 9 cr-leipzig1-po4-0.x-win.dfn.de ( ) ms 10 cr-erlangen1-po2-3.x-win.dfn.de ( ) ms 11 ar-regensburg1-po0-0.x-win.dfn.de ( ) ms 12 ar-regensburg2-ge0-0-0.x-win.dfn.de ( ) ms ( ) ms e-VLBI network K5 intensive session
Time Schedule (INT2) Sat Sun Mon JST: UTC+9h FTP convert FTP convert Correlation etc Obs. Submit to IVS Turnaround period (Best case) Sat. session : 2 days Sun. session: 1 day Mark5 to PC Mark5 to PC
Turnaround period (INT1&2) 2006 (Jan.-Aug.)2005 Average days K4K5Mark4/
processing factor (PF) = total length of correlation total length of a session efficiency comparison with PF from intensive session Better
Contribution to Deep Impact mission ( C ) NASA JPL ・ UT1 value provided by INT session eVLBI observations for IVS-INT2 ・ Data transfer for short time Contribution to the success of the mission Traveling at a relative velocity of 10 km/s and from about 864,000 km (536,865 miles) away, the impactor must strike the 6 km (3.7 mile) diameter comet. ( C ) NASA JPL 4 July 2005
UT1 during the Mission Prediction UT1 from VLBI observ. (not yet) 4-July Mission Date 2.2msec Equivalent to orbit error 21km
UT1 during the Mission INT2 (eVLBI) INT1 Result from VLBI (released) 4-July 1.1msec Equivalent to orbit error 10km
UT1 during the Mission 4-July 0.6msec Equivalent to orbit error 6km INT2 (eVLBI) INT1
UT1 during the Mission 4-July 0.6msec Equivalent to orbit error 6km INT2 (eVLBI) INT1
UT1 during the Mission 4-July 0.4msec Equivalent to orbit error 4km INT2 (eVLBI) INT1
UT1 during the Mission IMPACT 5:52 UT 4-July Success! INT2 (eVLBI) INT1 ©NASA JPL
Mon-Fri Sat-Sun Intensive session result (1) Leap second
Intensive session result (2) INT1 INT2 C04: the daily UT1-UTC by IERS CONT05 GSI WACO
CONT05 session ・ 11 VLBI stations participated in CONT05 sessions ・ The 15 days of continuous VLBI observation (September 12, 2005 ~ September 27,2005) ・ The goal is analysis of the high frequency(sub-daily) earth orientation parameter. Observation network
INT1&2 with CONT05 INT1(Kk-Wz) 18:30-19:30 UT INT2(Ts-Wz) 7:30- 8:30 UT 11 hours diff. Sub-daily variation
Thank you