Earth System Parameters and Orbit Dynamics

Head: Prof. Dr. Rolf König

Typical Earth system parameters are parameters which describe the Earth's geometrical and physical shape (ground station coordinates or gravity field spherical harmonic coefficients) and its orientation in space (Earth orientation parameters (EOP)). We estimate these Earth system parameters based on observations of satellite orbit dynamics which can be observed by various types of tracking data such as Satellite Laser Ranging (SLR), Global Navigation Satellite System (GNSS), Doppler Orbitography and Radiopositioning Integrated by Satellite (DORIS) and other data. The satellite orbit dynamics are driven by conservative (the gravity field) and non-conservative (the drag by the atmosphere, pressure by solar radiation, etc.) forces. Both these types of forces are modeled and parameterized in our core Earth Parameter and Orbit System software package EPOS. By evaluating the observations in EPOS in a least squares sense, the parameters we are interested in can be inferred with high accuracy and at the same time highly accurate orbits can be determined.

For this we

  • keep and develop knowledge in satellite orbit dynamics,
  • maintain and develop our sophisticated software package EPOS,
  • integrate a huge ensemble of terrestrial and space-borne observation types and space missions in our solutions
  • solve for orientation, center location and shape of the Earth
  • share our findings and take an active part in the IAG services IERS for geodetic satellites ILRS and 'International DORIS Service' (IDS) and 'International GNSS Service' (IGS)
  • deal with fundamental physics by cooperating internationally in testing of the general relativity principle by means of satellite dynamics.

The most important projects of Topic 3 are therefore:


Ciufolini, I., Paolozzi, A., Pavlis, E., Koenig, R., Ries, J., Gurzadyan, V., Matzner, R., Penrose, R., Sindoni, G., Paris, C., Khachatryan, H., Mirzoyan, S. (2016): A Test of General Relativity using the LARES and LAGEOS Satellites and a GRACE Earth's Gravity Model. European Physical Journal C, 76:120

Rudenko, S., Dettmering, D., Esselborn, S., Fagiolini, E., Schoene, T. (2016): Impact of Atmospheric and Oceanic De-aliasing Level-1B (AOD1B) products on precise orbits of altimetry satellites and altimetry results. Geophysical Journal International, 204, 3, p. 1695-1702,

Schuh, H., Koenig, R., Ampatzidis, D., Glaser, S., Flechtner, F., Heinkelmann, R., Nilsson, T.J. (2016 online): GGOS-SIM - Simulation of the Reference Frame for the Global Geodetic Observing System. International Association of Geodesy Symposia, Symposium 2014 on Reference Frames for Applications in Geosciences, Luxembourg, Springer, doi:10.1007/1345_2015_217

Jaeggi, A., Montenbruck, O., Moon, Y., Wermuth, M., Koenig, R., Michalak, G., Bock, H., Bodenmann, D. (2012): Inter-agency comparison of TanDEM-X baseline solutions. Advances in Space Research, doi: 10.1016/j.asr.2012.03.027

Zhu, S., Reigber, Ch., Koenig, R. (2004): Integrated Adjustment of CHAMP, GRACE, and GPS Data. Journal of Geodesy, Vol. 78, No. 1-2, pp. 103-108


Mr. Prof. Dr. Rolf König
Global Geomonitoring and Gravity Field

Münchner Str. 20
Building c/o DLR Oberpfaffenhofen, room 106
82234 Weßling
tel. +49 8153 90832 14