Journal of Geodesy

, Volume 85, Issue 7, pp 415–423 | Cite as

Universal time from VLBI single-baseline observations during CONT08

  • Tobias Nilsson
  • Johannes Böhm
  • Harald Schuh
Original Article


The IVS Intensive sessions are single-baseline, 1-h VLBI sessions carried out everyday in order to determine Universal Time (UT1). We investigate different possibilities to improve the results of such sessions. We do this investigation by extracting 2-h single-baseline sessions from the CONT08 data set. These are analysed like normal Intensives, and the results are compared to the results of the analysis of the full CONT08 data set. We find that tropospheric asymmetry is the major error source for the single-baseline sessions. It is possible to improve the accuracy of the estimated UT1 either by using accurate a priori tropospheric gradients or by estimating gradients in the data analysis.


VLBI Universal Time Earth rotation Tropospheric gradients 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Bizouard C, Gambis D (2009) The combined solution C04 for Earth orientation parameters consistent with international terrestrial reference frame 2005. In: Geodetic reference frames, IAG symposium, vol 134. Springer, Munich, Germany, pp 265–270. doi: 10.1007/978-3-642-00860-3_41
  2. Böckmann S, Artz T, Nothnagel A (2010) VLBI terrestrial reference frame contributions to ITRF2008. J Geodesy 84: 201–219. doi: 10.1007/s00190-009-0357-7 CrossRefGoogle Scholar
  3. Böhm J, Schuh H (2007a) Forecasting data of the troposphere used for IVS intensive sessions. In: Böhm J, Pany A, Schuh H (eds) Proceedings of the 18th working meeting European VLBI for geodesy and astrometry, Vienna, Austria, pp 153–157.
  4. Böhm J, Schuh H (2007b) Tropospheric gradients from the ECMWF in VLBI analysis. J Geodesy 81(6–8): 409–421. doi: 10.1007/s00190-006-0126-9 Google Scholar
  5. Böhm J, Spicakova H, Plank L, Teke K, Pany A, Wresnik J, Englich S, Nilsson T, Schuh H, Hobiger T, Ichikawa R, Koyama Y, Gotoh T, Kubooka T, Otsubo T (2009) Plans for the Vienna VLBI software VieVS. In: Proceedings of the 19th working meeting European VLBI for geodesy and astrometry, Bordeaux, France, pp 161–164Google Scholar
  6. Böhm J, Hobiger T, Ichikawa R, Kondo T, Koyama Y, Pany A, Schuh H, Teke K (2010a) Asymmetric tropospheric delays from numerical weather models for UT1 determination from VLBI intensive sessions on the baseline Wettzell–Tsukuba. J Geodesy 84: 319–325. doi: 10.1007/s00190-010-0370-x CrossRefGoogle Scholar
  7. Böhm J, Nilsson T, Schuh H (2010b) Prospects for UT1 measurements from Intensive sessions. In: Proceedings of 6th IVS general meeting, Hobart, Tasmania, Australia (in press)Google Scholar
  8. Fey A, Gordon D, Jacobs CS (eds) (2009) The second realization of the international celestial reference frame by Very Long Baseline Interferometry. IERS Technical Note 35. Verlag des Bundesamts für Kartographie und Geodäsie, Frankfurt am MainGoogle Scholar
  9. Hefty J, Gontier AM (1997) Sensitivity of UT1 determined by single-baseline VLBI to atmospheric delay model, terrestrial and celestial reference frames. J Geodesy 71: 253–261CrossRefGoogle Scholar
  10. Luzum B, Nothnagel A (2010) Improved UT1 predictions through low-latency VLBI observations. J Geodesy 84: 399–402. doi: 10.1007/s00190-010-0372-8 CrossRefGoogle Scholar
  11. Matsuzaka S, Shigematsu H, Kurihara S, Machida M, Kokado K, Tanimoto D (2008) Ultra rapid UT1 experiment with e-VLBI. In: Finkelstein A, Behrend D (eds) Proceedings of the fifth IVS general meeting: measuring the future, pp 68–71.
  12. McCarthy DD, Petit G (eds) (2004) IERS conventions 2003. IERS Technical Note 32. Verlag des Bundesamts für Kartographie und Geodäsie, Frankfurt am MainGoogle Scholar
  13. Nilsson T, Böhm J, Schuh H (2010) Sub-diurnal Earth rotation variations observed by VLBI. Artif Satell 45(2): 49–55. doi: 10.2478/v10018-010-0005-8 CrossRefGoogle Scholar
  14. Nothnagel A, Schnell D (2008) The impact of errors in polar motion and nutation on UT1 determinations from VLBI intensive observations. J Geodesy 82: 863–869. doi: 10.1007/s00190-008-0212-2 CrossRefGoogle Scholar
  15. Ray JR, Carter WE, Robertson DS (1995) Assessment of the accuracy of daily UT1 determinations by very long baseline interferometry. J Geophys Res 100(B5): 8193–8200CrossRefGoogle Scholar
  16. Robertson DS, Carter WE, Campbell J, Schuh H (1985) Daily Earth rotation determinations from IRIS very long baseline interferometry. Nature 316: 424–427CrossRefGoogle Scholar
  17. Schlüter W, Behrend D (2007) The International VLBI Service for Geodesy and Astrometry (IVS): current capabilities and future prospects. J Geodesy 81(6–8): 379–387. doi: 10.1007/s00190-006-0131-z CrossRefGoogle Scholar
  18. Sekido M, Takiguchi H, Koyama Y, Kondo T, Haas R, Wagner J, Ritakari J, Kurihara S, Kokado K (2008) Ultra-rapid UT1 measurement by e-VLBI. Earth Planets Space 60: 865–870Google Scholar
  19. Teke K, Böhm J, Nilsson T, Schuh H, Steigenberger P, Dach R, Heinkelmann R, Willis P, Haas R, Garcia-Espada S, Hobiger T, Ichikawa R, Shimizu S (2010) Multi-technique comparison of troposphere zenith delays and gradients during CONT08. J Geodesy. doi: 10.1007/s00190-010-0434-y, (in press)

Copyright information

© Springer-Verlag 2011

Authors and Affiliations

  1. 1.Institute of Geodesy and GeophysicsVienna University of TechnologyViennaAustria

Personalised recommendations