HR: 1340h
AN: G43B-0808    [Abstracts]
TI: Near Real-time UT1 Measurement by Using e-VLBI Technique
AU: * Kondo, T
EM: kondo@nict.go.jp
AF: Kashima Space Research Center/NICT, 893-1 Hirai, Kashima, Ibaraki, 314-0012 Japan
AU: Koyama, Y
EM: koyama@nict.go.jp
AF: Kashima Space Research Center/NICT, 893-1 Hirai, Kashima, Ibaraki, 314-0012 Japan
AU: Takeuchi, H
EM: ht@nict.go.jp
AF: Kashima Space Research Center/NICT, 893-1 Hirai, Kashima, Ibaraki, 314-0012 Japan
AU: Hirabaru, M
EM: masaki@nict.go.jp
AF: National Institute of Information and Communications Technology, 4-2-1 Nukui-kita, Koganei, Tokyo, 184-8795 Japan
AU: Takashima, K
EM: takasima@gsi.go.jp
AF: Geographical Survey Institute, 1 Kitasato, Tsukuba, Ibaraki, 305-0811 Japan
AU: Lapsley, D
EM: dlapsley@haystack.mit.edu
AF: Haystack Observatory, MIT, Off Route 40, Westford, MA 01886-1299 United States
AU: Dudevoir, K
EM: kad@planck.haystack.edu
AF: Haystack Observatory, MIT, Off Route 40, Westford, MA 01886-1299 United States
AU: Whitney, A
EM: awhitney@haystack.mit.edu
AF: Haystack Observatory, MIT, Off Route 40, Westford, MA 01886-1299 United States
AB: Recent progress of e-VLBI technique and the increase of network speed made rapid UT1 measurements possible. On June 30, 2004 we performed a one-hour e-VLBI session with the baseline between Kashima and Westford stations to estimate UT1 as rapid as possible. Observation data were recorded with the K5/VSSP system at Kashima and the Mark-5 system at Westford. Immediately after the session was finished, Mark-5 data were transferred to Kashima through the Internet. The Mark-5 data were then converted to K5 format data. In the next step, the converted data were correlated with those recorded at Kashima by using the K5 software correlator combined with the network-distributed processing system named VLBI@home. Finally we succeeded to obtain estimated UT1 value in as short as 4.5 hours after the session was over. To shorten the turn-around time of UT1 estimation further, we are improving the K5 software correlator so as to correlate K5 data with Mark-5 data directly. We are also developing software to send K5 data over network according to the standard data format (VSI-E). In addition to the rapid UT1 measurement results, we will report about current status of these software developments.
DE: 6924 Interferometry
DE: 6974 Signal processing
DE: 1239 Rotational variations
DE: 1294 Instruments and techniques
SC: Geodesy [G]
MN: 2004 AGU Fall Meeting