High Resolution Gravity Field Modeling with Full Variance-Covariance Matrices

High resolution gravity field models currently are computed by a combination of least squares adjustment with the full variance-covariance matrix for the lower degrees and a simplified approach for the higher degrees. Simplification means, that numerical quadrature is applied or that the structure of the covariance matrix is reduced to block-diagonals. Both methods have been used since several years to compute high resolution gravity field models. With recent improvements in algorithms and by the usage of parallel computers the degree and order for full variance-covariance matrices could be increased to 180. Several test solutions with combination of full and block-diagonal normals were computed and compared to independent data sets. Comparisons between the simplified and the rigorous approach show, that especially in the spectral domain better results can be reached with the full variance-covariance matrix.