Satellite Gravimetry

The Institute of Geodesy has been working on satellite-based gravity data for years. The spectrum of activities ranges from the calculation of regional (and global) gravity field solutions to extensive data analysis and studies of geophysical phenomena such as permafrost in Siberia.

 

 

© DLR, ESA, JPL (modifiziert)
The gravity field satellite missions CHAMP, GRACE and GOCE.

Satellite Gravimetry investigates the gravity field of the Earth including its time variations, using satellite measurement methods, in particular:

  • by tracking gravitational orbital disturbances of low and medium satellites, e.g. the current three-satellite constellation Swarm,
  • by satellite-to-satellite tracking between low-flying Earth satellites like
  • at present the GRACE Follow-On mission, with satellite gradiometry like the GOCE mission (2009-2013).

 

The measurement data from these missions are part of the Global Geodetic Observing System (GGOS). They are used for the quantification of global processes of change, e.g. the determination of the mass loss of the Polar ice shields, and contribute to the precise realization of global geodetic reference systems.

Data analysis is based on extensive estimation procedures for the joint determination of gravity field, orbit and sensor parameters from multi-annual high-resolution measurement time series.

Here, sensor analysis, mathematical quality evaluation of the parameter estimation as well as the spacial-temporal interpretation of geophysical results are tightly connected. Current research investigates error propagation and stochastic modelling under consideration of satellite orbit dynamics and environmental influences.