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A regularized solution of boundary problems in combining terrestrial and satellite gravity field data

Petr Holota(1) and Otakar Nesvadba(2)

(1) Research Institute of Geodesy, 250 66 Zdiby 98, Praha-vychod, Czech Republic
(2) Land Survey Office, Pod Sídlistem 9, 182 11 Praha 8, Czech Republic

Abstract

The purpose of this paper is to discuss an optimization concept in combining terrestrial and satellite gravity field data and to show its spectral and space domain interpretation. The problems under study are overdetermined by nature. Therefore, methods typical for the solution of boundary-value problems have been applied together with an optimization approach. Two cases are treated in this paper. They are motivated by the use of satellite-only models of the gravity field of the Earth and by data coming from satellite missions like e.g. GOCE (treated within the so-called space-wise approach) in common with terrestrial gravity measurements. For the results reached in the spectral domain the use of series summation techniques has been investigated in order to find their interpretation in terms of Green’s functions related to the particular combination scheme. This makes it possible to show the tie between the global and the local modelling of the gravity field. In order to check the efficiency of the procedure discussed in this paper extensive simulations have been done. The whole approach has been tested numerically by means of simulated input data derived from the potential of the gravity field model EGM96 and the potential of the Somigliana-Pizzetti normal gravity field with parameters given in GRS1980. Differences in the “closed loop” simulation do not exceed 0.06 GeoPotential Units. Problems of theoretical and practical nature are discussed in this connection.

 

Workshop poster

Keywords: ESA European Space Agency - Agence spatiale europeenne, observation de la terre, earth observation, satellite remote sensing, teledetection, geophysique, altimetrie, radar, chimique atmospherique, geophysics, altimetry, radar, atmospheric chemistry