Global gravity field determination with regional refinements by the analysis of GOCE-level-1b data (GLOREGOCE)

Abstract

In this contribution, we present regionally refined gravity field models from GOCE data only using the short arc processing. For easy comparison, regional solutions calculated on small patches all over the globe have been merged and transformed to a spherical harmonic expansion by means of quadrature methods. The power of the regional approach is demonstrated by comparison to the previously calculated ITG-Goce01/ITG-Goce02 spherical harmonic models, which are based on exactly the same processing strategy, standards and data time span. We show, that these global models are comparable in accuracy with respect to the official ESA time-wise models. Second, we verify the gain of regional modelling with respect to our global models: Compared to EGM08 cut to the oceans, using a land/ocean adjustment of regularisation reduces the global noise by 11%. A more tailored choice of the regularisation areas tested for the South Sandwich Trench reveals the significant improvement of 18%.