Regional gravity modeling in terms of spherical base functions

This article provides a survey on modern methods of regional gravity field modeling on the sphere. Starting with the classical theory of spherical harmonics,weoutline the transition towards space-localizing methods such as spherical splines and wavelets. Special emphasis is given to the relations among these methods, which all involve radial base functions. Moreover, we provide extensive applications of these methods and numerical results from real space-borne data of M. Schmidt (B) · L. Sánchez Deutsches Geodätisches Forschungsinstitut (DGFI), Alfons-Goppel-Strasse 11, 80539 Munich, Germany e-mail: [email protected] L. Sánchez e-mail: [email protected] M. Fengler Geomathematics Group, Technical University of Kaiserslautern, P.O. Box 3049, 67653 Kaiserslautern, Germany e-mail: [email protected] T. Mayer-Gürr · A. Eicker Institute of Theoretical Geodesy, University of Bonn, Nussallee 17, 53115 Bonn, Germany e-mail: [email protected] A. Eicker e-mail: [email protected] J. Kusche Delft Institute of Earth Observation and Space Systems (DEOS), Delft University of Technology, Kluyverweg 1, P.O. Box 5058, 2600 GB Delft, The Netherlands e-mail: [email protected] S.-C. Han Geodetic Science, Department of Geological Sciences, Ohio State University, Columbus, USA e-mail: [email protected] recent satellite gravity missions, namely the Challenging MinisatellitePayload (CHAMP)and theGravityRecovery and Climate Experiment (GRACE). We also derive high-resolution gravity field models by effectively combining space-borne and surface measurements using a new weighted level-combination concept. In addition, we outline and apply a strategy for constructing spatiotemporal fields from regional data sets spanning different observation periods.