Integration of Earth rotation, geometry and gravity field using geodetic space techniques

This project is funded within the research group "Earth rotation and global dynamic processes" (FOR584) of the German Research Foundation (DFG). The aim of the project is to deliver long time series of consistently estimated parameters of the Earth's rotation and their derivatives (EOPs: coordinates of the terrestrial and celestial pole, UT1), the Earth's geometry (station positions and their non-linear time-dependent evolution) and the Earth's gravity field (low degree spherical harmonics). These parameters play a fundamental role in various projects of the research group.

Input data are long time series of the geodetic space observation techniques GPS, VLBI and SLR. Much attention is drawn on the usage of homogeneous models and constants. The observation techniques show different strengths in deriving the Earth's parameters and therefore the combination of the data allows a consistent estimation. Possible systematic effects of the individual techniques could be discovered and separated from the estimated parameters in the combination.

The main subtasks are:

  • Implementation of the EOPs time derivatives in the combination
  • Improved estimation of the low-degree spherical harmonic coefficients
  • Development of advanced combination methods
  • Generation of observation time series by homogeneous processing
Upper part: estimated coordinates of the terrestrial pole in x-direction using observations to the geodetic space techniques GPS (green), VLBI (red) and SLR (blue). Additionally the weekly combination of all techniques is shown (black). Lower part: estimated coordinates of the terrestrial pole in x-direction of the 4-weekly (magenta) and the weekly (black) combination of all techniques.

Selected Publications

Göttl F., Schmidt M., Seitz F., Bloßfeld M.: Separation of atmospheric, oceanic and hydrological polar motion excitation mechanisms based on a combination of geometric and gravimetric space observations. Journal of Geodesy 89(4): 377-390, Springer, 10.1007/s00190-014-0782-0, 2015
Schmidt M., Göttl F., Heinkelmann R.: Towards the combination of data sets from various observation techniques. In: Kutterer H., Seitz F., Alkhatib H., Schmidt M. (Eds.) The 1st International Workshop on the Quality of Geodetic Observation and Monitoring Systems (QuGOMS'11), IAG Symposia 140: 35-43, Springer, 10.1007/978-3-319-10828-5_6, 2015
Bloßfeld M., Müller H., Gerstl M., Stefka V., Bouman J., Göttl F., Horwath M.: Second-degree Stokes coefficients from multi-satellite SLR. Journal of Geodesy 89(9): 857-871, 10.1007/s00190-015-0819-z, 2015
Bloßfeld M., Seitz M., Angermann D.: Non-linear station motions in epoch and multi-year reference frames. Journal of Geodesy 88(1): 45-63, Springer, 10.1007/s00190-013-0668-6, 2014
Bloßfeld M., Gerstl M., Hugentobler U., Angermann D., Müller H.: Systematic effects in LOD from SLR observations. Advances in Space Research 54(6): 1049-1063, 10.1016/j.asr.2014.06.009, 2014
Seitz M., Angermann D., Drewes H.: Accuracy assessment of the ITRS 2008 realization of DGFI: DTRF2008. In: Altamimi Z., Collilieux X. (Eds.) Reference Frames for Applications in Geosciences, IAG Symposia 138: 87-93, Springer, 10.1007/978-3-642-32998-2_15, 2013
Göttl F.: Kombination geodätischer Raumbeobachtungen zur Bestimmung von geophysikalischen Anregungsmechanismen der Polbewegung. Deutsche Geodätische Kommission, Reihe C, Heft 714, Verlag der Bayerischen Akademie der Wissenschaften, ISBN 978-3-7696-5126-3, 2013
Göttl F., Schmidt M., Heinkelmann R., Savcenko R., Bouman J.: Combination of gravimetric and altimetric space observations for estimating oceanic polar motion excitations. J. Geophys. Res., 117, C10022, 10.1029/2012JC007915, 2012
Schmidt M., Angermann D., Bloßfeld M., Göttl F., Richter B., Seitz M.: Erdrotation und geophysikalische Anregungsmechanismen. Zeitschrift für Vermessungswesen, 135, Heft 2, 2010
Göttl F.: Earth rotation variations from geometric, gravimetric and altimetric observations and geophysical models. DGFI Report 84, Deutsches Geodätisches Forschungsinstitut (DGFI), Mänchen, 2008
Göttl F., Seitz F.: Contribution of non-tidal oceanic mass variations to polar motion determined from space geodesy and ocean data. in: Sideris, M.G. (ed.) Observing our Changing Earth, IAG Symposia 133: 439-445, Springer, 10.1007/978-3-540-85426-5_53, 2008

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