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GOCE: dealing with large attitude variations in the conceptual structure of the space-wise approach

Dr Mirko Reguzzoni(1), Prof Federica Migliaccio(1) , Prof Fernando Sansò(1) , and Dr Paolo Zatelli(2)

(1) Politecnico di Milano, Via Valleggio, 11, 22100 Como, Italy
(2) Università di Trento, Via Mesiano,77, 38050 Trento, Italy

Abstract

The space-wise approach to the analysis of GOCE data utilizes a grid of convenient “geographic” second order derivatives on a boundary sphere at satellite altitude. These derivatives are to be predicted from actually observed data, which include second derivatives along instrumental axes; in fact the instrumental and geographic frames are not perfectly aligned (e.g. the z-axis is not radial). The prediction can be performed by collocation by exploiting the full covariance (and cross-covariance) of the second derivatives tensors in two arbitrarily rotated frames. This solution is being implemented by UCPH and it has to work only with local data for the well-known limitation in the numerical handling of collocation formula. Since the “radial” component Trr is the most informative component, we are particularly interested in the effect of the misalignment on the prediction of Trr. In this respect Tzz is the most important contributor because the z-axis is very close to the radial axis. In the paper we present a study on the possibility of performing this prediction by applying a Wiener filter along the orbit, exploiting the full spatial covariance structure of T, as it has been recently done by POLIMI, in a simpler context.

 

Full paper

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

GOCE04