Print Email Facebook Twitter The Impact of Noise in a GRACE/GOCE Global Gravity Model on a Local Quasi-Geoid Title The Impact of Noise in a GRACE/GOCE Global Gravity Model on a Local Quasi-Geoid Author Slobbe, D.C. (TU Delft Physical and Space Geodesy) Klees, R. (TU Delft Physical and Space Geodesy) Farahani, H. (Geodätisches Institut, Stuttgart) Huisman, L. (Kadaster) Alberts, Bas (Ministry of Infrastructure and the Environment) Voet, Pierre (Nationaal Geografisch Instituut, Brussel) Doncker, Filip De (Nationaal Geografisch Instituut, Brussel) Date 2019 Abstract We present a local quasi-geoid (QG) model which combines a satellite-only global gravity model with local data sets using weighted least squares. The QG is computed for an area comprising the Netherlands, Belgium, and the southern North Sea. It uses a two-scale spherical radial basis function model complemented by bias parameters to account for systematic errors in the local gravity data sets. Variance factors are estimated for the noise covariance matrices of all involved data sets using variance component estimation. The standard deviation (SD) of the differences between the computed QG and GPS/leveling data is 0.95 and 1.52 cm for the Netherlands and Belgium, respectively. The fact that the SD of the control data is about 0.60 and 1.20 cm for the Netherlands and Belgium, respectively, points to a lower mean SD of the computed QG model of about 0.7 cm for the Netherlands and 1.0 cm for Belgium. The differences to a QG model computed with the remove-compute-restore technique range from −5.2 to 2.6 cm over the whole model domain and from −1.5 to 1.5 cm over the Netherlands and Belgium. A variogram analysis of the differences with respect to GPS/leveling data reveals a better performance of the computed QG model compared to a remove-compute-restore-based QG model for wavelengths >100 km for Belgium but not for the Netherlands. The latter is due to the fact that at the spatial scales resolved by the global gravity model, variance component estimation assigns significantly lower weights to the local data set in favor of the global gravity model. Subject geoidGPS/levelingsatellite-only global gravity modelspherical radial basis functionsweighted least squares To reference this document use: http://resolver.tudelft.nl/uuid:417447d4-c1a5-472b-95c4-b4000d663b93 DOI https://doi.org/10.1029/2018JB016470 ISSN 2169-9313 Source JGR Solid Earth, 124 (3), 3219-3237 Part of collection Institutional Repository Document type journal article Rights © 2019 D.C. Slobbe, R. Klees, H. Farahani, L. Huisman, Bas Alberts, Pierre Voet, Filip De Doncker Files PDF Slobbe_et_al_2019_Journal ... _Earth.pdf 3.06 MB Close viewer /islandora/object/uuid:417447d4-c1a5-472b-95c4-b4000d663b93/datastream/OBJ/view