Journal of Geodesy

, Volume 81, Issue 6–8, pp 529–541 | Cite as

Combined Earth orientation parameters based on homogeneous and continuous VLBI and GPS data

  • Daniela ThallerEmail author
  • Manuela Krügel
  • Markus Rothacher
  • Volker Tesmer
  • Ralf Schmid
  • Detlef Angermann
Original Article


The CONT02 campaign is of great interest for studies combining very long baseline interferometry (VLBI) with other space-geodetic techniques, because of the continuously available VLBI observations over 2 weeks in October 2002 from a homogeneous network. Especially, the combination with the Global Positioning System (GPS) offers a broad spectrum of common parameters. We combined station coordinates, Earth orientation parameters (EOPs) and troposphere parameters consistently in one solution using technique- specific datum-free normal equation systems. In this paper, we focus on the analyses concerning the EOPs, whereas the comparison and combination of the troposphere parameters and station coordinates are covered in a companion paper in Journal of Geodesy. In order to demonstrate the potential of the VLBI and GPS space-geodetic techniques, we chose a sub-daily resolution for polar motion (PM) and universal time (UT). A consequence of this solution set-up is the presence of a one-to-one correlation between the nutation angles and a retrograde diurnal signal in PM. The Bernese GPS Software used for the combination provides a constraining approach to handle this singularity. Simulation studies involving both nutation offsets and rates helped to get a deeper understanding of this singularity. With a rigorous combination of UT1–UTC and length of day (LOD) from VLBI and GPS, we showed that such a combination works very well and does not suffer from the systematic effects present in the GPS-derived LOD values. By means of wavelet analyses and the formal errors of the estimates, we explain this important result. The same holds for the combination of nutation offsets and rates. The local geodetic ties between GPS and VLBI antennas play an essential role within the inter-technique combination. Several studies already revealed non-negligible discrepancies between the terrestrial measurements and the space-geodetic solutions. We demonstrate to what extent these discrepancies propagate into the combined EOP solution.


CONT02 Rigorous combination Sub-daily Earth rotation Nutation Local ties 


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  1. Altamimi Z, Sillard P, Boucher C (2002) ITRF2000: A new release of the International Terrestrial Reference Frame for Earth science applications. J Geophys Res 107(B10):2214, doi:10.1029/2001JB000561CrossRefGoogle Scholar
  2. Altamimi Z, Boucher C, Willis P (2005) Terrestrial reference frame requirements within GGOS perspective. J Geodyn 40(4,5):363–374, doi:10.1016/j.jog.2005.06.002CrossRefGoogle Scholar
  3. Andersen PH (2000) Multi-level arc combination with stochastic parameters. J Geod 74(7,8):531–551, doi:10.1007/ s001900000115CrossRefGoogle Scholar
  4. Angermann D, Drewes H, Krügel M, Meisel B, Gerstl M, Kelm R, Müller H, Seemüller W, Tesmer V (2004) ITRS Combination Center at DGFI: a terrestrial reference frame realization 2003. Deutsche Geodätische Kommission, Reihe B, Heft Nr. 313, MunichGoogle Scholar
  5. Brockmann E (1997) Combination of solutions for geodetic and geophysical applications of the global positioning system (GPS). PhD Thesis. Geodätisch-Geophysikalische Arbeiten in der Schweiz, Band 55. Available at: Scholar
  6. Dill R, Rothacher M (2003) IERS analysis campaign to align EOP to ITRF2000 / ICRF. In: Observation of the system earth from space, status seminar at the Bavarian State Mapping Agency (BLVA), Munich, 12–13 June 2003, Programme and Abstracts, GEOTECHNOLOGIEN Science Report No. 3, Koordinierungsbüro GEOTECHNOLOGIEN, Potsdam, ISSN 1619–7399Google Scholar
  7. Gambis D (1986) On the possibility of detecting some terms of the diurnal polar motion by the study of satellite orbits. Adv Space Res 6(9):33–36, doi:10.1016/0273-1177(86)90347-9CrossRefGoogle Scholar
  8. Gambis D (2004) Monitoring Earth orientation using space- geodetic techniques: state-of-the-art and prospective. J Geod 78(4,5):295–303, doi:10.1007/s00190-004-0394-1CrossRefGoogle Scholar
  9. Goupillaud P, Grossmann A, Morlet J (1984) Cycle-octave and related transforms in seismic signal analysis. Geoexploration 23(1):85–102, doi:10.1016/0016-7142(84)90025-5CrossRefGoogle Scholar
  10. Gross RS (2000) Combinations of Earth-orientation measurements SPACE97, COMB97, and POLE97. J Geod 73(12): 627–637, doi:10.1007/s001900050001CrossRefGoogle Scholar
  11. Gross RS, Eubanks TM, Steppe JA, Freedman AP, Dickey JO, Runge TF (1998) Kalman-filter-based approach to combining independent Earth-orientation series. J Geod 72(4):215–235, doi:10.1007/s001900050162CrossRefGoogle Scholar
  12. Heflin MB (2003) IGS reference site candidates. IGSMAIL-4281. msg00059.htmlGoogle Scholar
  13. Hefty J, Rothacher M, Springer T, Weber R, Beutler G (2000) Analysis of the first year of Earth rotation parameters with a sub-daily resolution gained at the CODE processing center of the IGS. J Geod 74(6):479–487, doi:10.1007/s001900000108CrossRefGoogle Scholar
  14. Herring TA, Dong D (1994) Measurement of diurnal and semidiurnal rotational variations and tidal parameters of Earth. J Geophys Res 99(B9):18051–18071, doi:10.1029/94JB00341CrossRefGoogle Scholar
  15. Hugentobler U, Dach R, Fridez P, Meindl M (eds) (2005) Bernese GPS Software Version 5.0. Astronomical Institute of the University of Berne, Switzerland. Draft version available at: Scholar
  16. Krügel M, Thaller D, Tesmer V, Schmid R, Rothacher M, Angermann D (2006) Tropospheric parameters: Combination studies based on homogeneous input data. J Geod (submitted)Google Scholar
  17. McCarthy DD, Petit G (2004) IERS conventions 2003. IERS technical note No. 32. Verlag des Bundesamts für Kartographie und Geodäsie, Frankfurt am MainGoogle Scholar
  18. Moritz H, Mueller II (1987) Earth rotation: theory and observation. Ungar Publishing Company, New York, ISBN 0-8044-4671-7Google Scholar
  19. Ray J, Altamimi Z (2005) Evaluation of co-location ties relating the VLBI and GPS reference frames. J Geod 79(4,5):189–195, doi:10.1007/s00190-005-0456-zCrossRefGoogle Scholar
  20. Ray J, Kouba J, Altamimi Z (2005) Is there utility in rigorous combinations of VLBI and GPS Earth orientation parameters? J Geod 79(9):505–511, doi:10.1007/s00190-005-0007-7CrossRefGoogle Scholar
  21. Rothacher M, Beutler G, Herring TA, Weber R (1999) Estimation of nutation using the Global Positioning System. J Geophys Res 104(B3):4835–4859, doi:10.1029/1998JB900078CrossRefGoogle Scholar
  22. Thaller D, Rothacher M (2003) Comparison and combination of GPS, VLBI and SLR solution series. In: Observation of the system Earth from space, status seminar at the Bavarian State Mapping Agency (BLVA), Munich, 12–13 June 2003, Programme and Abstracts, GEOTECHNOLOGIEN Science Report No. 3, Koordinierungsbüro GEOTECHNOLOGIEN, Potsdam, ISSN 1619–7399Google Scholar
  23. Thaller D, Krügel M, Angermann D, Rothacher M, Schmid R, Tesmer V (2005) Combination Studies Using the CONT02 Campaign. In: Behrend D, Baver K (eds) International VLBI service for geodesy and astrometry 2004 annual report, NASA/TP-2005-212772. NASA Goddard Space Flight Center, Greenbelt, MDGoogle Scholar
  24. Thaller D, Krügel M, Tesmer V, Rothacher M, Schmid R, Angermann D (2006) Combination of Earth Orientation Parameters. In: Proceedings of the IERS Workshop on Combination, held at GFZ Potsdam, 10–11 October 2005, Bundesamt für Kartographie und Geodäsie, Frankfurt am Main (in press)Google Scholar
  25. Thomas C, MacMillan DS (2003) CORE operation center report. In: Vandenberg NR, Baver KD (eds) International VLBI service for geodesy and astrometry 2002 annual report, NASA/TP-2003-211619. NASA Goddard Space Flight Center, Greenbelt, MDGoogle Scholar
  26. Thomas C, MacMillan DS (2006) CORE operation center report. In: Behrend D, Baver KD (eds) International VLBI service for geodesy and astrometry 2005 annual report, NASA/TP-2006-214136. NASA Goddard Space Flight Center, Greenbelt, MDGoogle Scholar
  27. Titov O, Tesmer V, Böhm J (2004) OCCAM V 6.0 software for VLBI data analysis. In: Vandenberg N, Baver K (eds) IVS 2004 General meeting proceedings, NASA/CP-2004-212255. NASA Goddard Space Flight Center, Greenbelt, MDGoogle Scholar
  28. Watkins MM, Eanes RJ (1994) Diurnal and semidiurnal variations in Earth orientation determined from LAGEOS laser ranging. J Geophys Res 99(B9):18073–18079, doi:10.1029/94JB00805CrossRefGoogle Scholar
  29. Yaya P (2002) Apport des combinaisons de techniques astrométriques et géodésiques à l’estimation des paramètres d’orientation de la terre. PhD thesis, Observatoire de ParisGoogle Scholar

Copyright information

© Springer-Verlag 2006

Authors and Affiliations

  • Daniela Thaller
    • 1
  • Manuela Krügel
    • 2
  • Markus Rothacher
    • 1
  • Volker Tesmer
    • 2
  • Ralf Schmid
    • 3
  • Detlef Angermann
    • 2
  1. 1.Department 1GeoForschungsZentrum Potsdam (GFZ)PotsdamGermany
  2. 2.Deutsches Geodätisches Forschungsinstitut (DGFI)MünchenGermany
  3. 3.Institut für Astronomische und Physikalische GeodäsieTU MünchenMünchenGermany

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