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  • Letter
  • Open Access

Ultra-rapid UT1 measurement by e-VLBI

  • 19Email author,
  • 19,
  • 19,
  • 19,
  • 29,
  • 39,
  • 39,
  • 49 and
  • 49
Earth, Planets and Space200860:BF03352838

  • Received: 31 October 2007
  • Accepted: 6 June 2008
  • Published:


The latency of UT1 measurement with Very Long Baseline Interferometry (VLBI) has been greatly reduced by using e-VLBI technology. VLBI observations on the baseline formed by the Kashima 34-m and the Onsala 20-m radio telescopes achieved ultra-rapid UT1 measurements, where the UT1 result was obtained within 30 min after the end of the observing session. A high speed network and a UDP-based data transfer protocol ‘Tsunami’ assisted the high data rate and long-distance data transfer from Onsala to Kashima. The accuracy of the UT1 value obtained from the 1-h single baseline e-VLBI experiment has been confirmed to be as the same level with the rapid combined solution of Bulletin-A. The newly developed technology is going to be transferred to the regular intensive VLBI sessions, and it is expected to contribute to the improved latency and accuracy of UT1 data.

Key words

  • E-VLBI
  • UT1