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