Global gravity field recovery by merging regional focusing patches: an integrated approach
Usually the gravity potential is modelled by a spherical harmonic expansion. Simulation tests and real-data investigations based on POD (precise orbit determination) and SST (satellite-to-satellite tracking) data demonstrated that the heterogeneity of the gravity field cannot be properly taken into account by base functions with global support. It is preferable to model the gravity field only up to a moderate safely determinable spherical harmonic degree without any regularization to cover the long and medium wavelengths characteristics; the specific detailed features tailored to the individual gravity field characteristics in areas of rough gravity field signal can be modelled additionally by space localizing base functions. In a final step, a spherical harmonic expansion up to a maximum degree, only limited by the most detailed structures of the gravity field, can be derived based on a Gauss-Legendre-Quadrature procedure. This last step can be performed without stability problems and without losing the regional details of the gravity field. The proposed integrated gravity field recovery approach integrates consistently a regional gravity field zoom-in into a global gravity field solution. The technique has been applied to the determination of gravity field models based on SST data of GRACE.
KeywordsCHAMP GRACE global gravity field recovery regional gravity field recovery
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- Eicker A, Mayer-Gürr T, Ilk, KH (2005) Global Gravity Field Solutions Based on a Simulation Scenario of GRACE SST Data and Regional Refinements by GOCE SGG Observations, in C. Jekeli, et al.: Gravity, Geoid and Space Missions — GGSM2004, Porto, Portugal, IAG International Symposium, International Association of Geodesy Symposia, Vol. 129, pp. 66–71, SpringerGoogle Scholar
- Förste C, Flechtner F, Schmidt R, Meyer U, Stubenvoll R, Barthelmes F, Neumayer KH, Rothacher M, Reigber C, Biancale R, Bruinsma S, Lemoine JM, Raimondo JC (2005) A New High Resolution Global Gravity Field Model Derived From Combination of GRACE and CHAMP Mission and Altimetry/Gravimetry Surface Gravity Data, Poster presented at EGU General Assembly 2005, Vienna, Austria, 24–29, April 2005Google Scholar
- Freeden W, Gervens T, Schreiner M (1998) Constructive Approximatiuon on the Sphere, Oxford University Press, OxfordGoogle Scholar
- Ilk KH, Mayer-Gürr T, Eicker A, Feuchtinger M, (2004) The Regional Refinement of Global Gravity Field Models from Kinematical Orbits, New Satellite Mission Results for the Geopotential Fields und Their Variations, Proceedings Joint CHAMP/GRACE Science Meeting, GFZ Potsdam, July 6–8Google Scholar
- Mayer-Gürr T, Eicker A, Ilk KH (2005b) Gravity field recovery from GRACE-SST data of short arcs, in: R. Rummel, et al. Observation of the Earth System from Space (in preparation), SpringerGoogle Scholar
- Reigber C, Schwintzer P, Lühr H (1999) The CHAMP geopotential mission, Boll. Geof. Teor. Appl., 40:285–289Google Scholar
- Stroud AH, Secrest D (1966) Gaussian Quadrature Formulas, Prentice-Hall, Englewood Cliffs, N.J.Google Scholar