Living Planet   


GOCE Quick-Look Gravity Field Analysis

Dr Roland Pail(1)

(1) Graz University of Technology, Steyrergasse 30, 8010 GRAZ, Austria


The satellite mission GOCE, the first Core Mission of ESA's Living Planet Explorer Programme funded by ESA, is dedicated to the precise modeling of the Earth's gravity field from satellite gravity gradiometry (SGG) and high-low satellite-to-satellite tracking (hl-SST) observations. The mathematical models for its parameterization are based on a series expansion into spherical harmonics, yielding a huge number of unknown coefficients, and efficient solution strategies are required to solve the corresponding large normal equation systems. The Quick-Look Gravity Field Analysis (QL-GFA) tool is based on the semi-analytic method. The purpose of QL-GFA is to analyze partial and/or incomplete data sets of SGG and hl-SST data, in order to derive a fast diagnosis of the GOCE system performance, by detecting potential distortions of statistical significance (e.g. systematic errors) in the input data, and to give a fast feedback to the GOCE mission control (Payload Data Segment). This procedure includes the estimation of the noise characteristics of the SGG time series, which is checked against the gradiometer error PSD, and of hl-SST time series, as well as the fast analysis of the information content of these data on the level of the gravity field solution. By means of an iterative strategy, QL-GFA can overcome the negative effect of data gaps, partial data sets and non-repeat orbits. The feasibility of the method to fulfill the intended tasks is demonstrated on the basis of numerical simulations with a realistic GOCE configuration, and special concern given to a realistic noise modelling of SGG and SST data.


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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