Acta Geodaetica et Cartographica Sinica

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The Simulation Research on the Tikhonov Regularization Applied in Gravity Field Determination of GOCE Satellite Mission

  

  • Received:2009-11-02 Revised:2010-03-15 Online:2010-10-25 Published:2010-10-25

Abstract: GOCE satellite has been launched in 17 March 2009, the main objective of which is to provide a global gravity field model up to the degree and order 200. At the same time, the accuracies of the geoid and the gravity anomaly are 1-2 cm and 1 mGal respectively. Because of the distribution of observation data (Polar Gap) and the downward continuation problem, to the determination of the high-degree gravity field model using GOCE data is usually an ill-posed problem, which can be dealt with by regularization techniques. The Tikhonov regularization is widely applied in the geodesy, the principle of which is discussed in this paper, also including the mathematical models of four types of regularization matrices (zero-order, first-order, second-order and Kaula) and the regularization parameter selection methods: L-curve and GCV. The validation of zero-order, first-order and Kaula regularization matrices applied in the gravity field determination with GOCE simulated data is analyzed based on the SA method. And also the applicability of L-curve and GCV is discussed using the simulated data. The results show that the accuracies of the optimized solutions (selected by minimizing geoid MSE) with the three types of regularization matrices are at the same level. The key point is the selection of the corresponding regularization parameter. The results also show that GCV and L-curve can be applied in the regularization parameter estimation, and the former method is more stable than the latter one.