[G03-P] Poster

[G03-P-02] Combination of monthly gravity fields on normal equation level

Ulrich Meyer, ^○Adrian Jaeggi, Yoomin Jean, Daniel Arnold (University of Bern, Bern, Switzerland)

In the frame of the Scientific Combination Service of the European Gravity Service for Improved Emergency Management (EGSIEM), monthly gravity fields of different analysis centers are combined on normal equation (NEQ) level. While common standards for reference frame, Earth rotation and satellite geometry ensure consistency of the NEQs, the different processing centers are free to apply their own processing strategies and to select different background models for de-aliasing and signal separation. The applied noise models are very inhomogeneous, too, and consequently standard procedures for NEQ combination like Variance Component Estimation fail. We present an alternative NEQ combination strategy where relative weights are defined based on the solution noise, as determined by pairwise comparisons of the individual contributions on solution level. We further investigate combination approaches where the individual NEQs are scaled prior to combination, with the goal to reach homogeneous levels of formal errors.