GOCOnAUT - Combined High-resolution Global Gravity Field Model from Satellite Gravity Missions GOCE, GRACE and CHAMP, Complemented by Terrestrial Gravity, Altimetry and SLR Data
These different data types are complementary with respect to their measurement principle, accuracy, spatial distribution and resolution, and spectral (error) characteristics. By means of data combination, benefit can be taken from their individual strengths and favourable features, and at the same time specific deficiencies can be reduced, leading finally to global models of the Earth’s gravity field with high spatial resolution and accuracy.
The models are parameterized in terms of coefficients of a spherical harmonic expansion including a proper error description in terms of a variance/covariance matrix. The data combination of the individual contributions is done on the basis of normal equations. In the frame of a synthetic test environment different challenges and issues of data combination are studied by several numerical simulations.
These simulations are to consider theoretical and methodological aspects and to evaluate, e.g., the effect of potential systematic errors, different reference frames and standards, optimum weighting techniques, full or block diagonal normal equation matrices, and regularization issues.
A high-accuracy and detailed global map of the Earth’s gravity field is an important product in many branches of Earth system sciences. In geophysics it is applied to improve the modelling of the Earth’s interior and geodynamic processes.
In combination with satellite radar altimetry, it improves the accuracy of the models of global ocean circulation, which is responsible for a large part of the global heat and energy transport, and thus plays a crucial role in climate regulation. It also contributes to observing and understanding sea-level change as a result of melting of ice sheets associated with a changing climate. Finally, also geodesy benefits from a unified definition of physical height systems.
Graz University of Technology, Institute of Navigation and Satellite Geodesy - Helmut Goiginger
Austrian Academy of Sciences, Space Research Institute, Department of Satellite Geodesy - Walter Hausleitner
Graz University of Technology - Institute of Navigation and Satellite Geodesy
Tel.: +43 (316) 873 6831