Theory And Methods Of The Earth's Gravity Field Model Recovery From GOCE Data

This dissertation focuses on the theory and methods of earth's gravity field model recovery from GOCE data. The main work and innovation points are listed as follows:(1) The traditional and non-singular detailed calculation models of all disturbing gravity gradient tensor components are constructed with the non-singular calculation formula of m 2 Pn m(cos ? ) sin2? is derived.(2) The downward continuation methods such as analytical method, Poisson integral iteration method and the data gridding methods such as moving average method, inverse distance weighting method, ordinary kriging method of satellite gravity gradients(SGG) are studied and modeled, which are applied in two schemes i.e. direct method and remove-restore method to test the downward continuation and gridding accuracy.(3) Each error of the energy balance approach method that influences the calculation of disturbing potential along the orbit is analyzed. The practical mathematic models of direct least squares method, harmonic analysis method and least squares collocation(LSC) method for solving earth's gravity field model from disturbing potential data are established.(4) The non-singular models of direct leasts square method and calculation model of harmonic analysis method for solving earth's gravity field model using each component and combined components of disturbing gravity gradient are constructed. Besides, the practical variance and covariance formulae of the disturbing gravity tensor components and the gravity potential coefficients are deduced.(5) Combined adjustment model for earth's gravity field model determination from various types of gravimetry data is derived, in which the basic principles of parametric covariance approach(PCA) method and variance components estimation(VCE) method in the best selection of weight ratio are introduced and analyzed.(6) The basic principle of spectral combination method is discussed before the general expressions of the spectral weight and spectral combination using various types of gravimetry data are shown. What's more, based on harmonic analysis, the detailed forms of spectral combination formula and the corresponding spectral weights in the earth's gravity model determination using SST+SGG, SST+SGG+Δg and SST+SGG+Δg+N are derived.(7) Basic formulae of earth's gravity field model recovery using iteration method from the combination of various types of gravimetry data are deduced, and the detailed realization steps are given.(8) The design index of gravity satellite orbit altitude, inter-satellite range and the orbit inclination are studied and calculated. The issues towards the two satellites such as alignment of the semimajor axes, pitch attitude control and time interval to keep the satellite formation are discussed.(9) The precision index of inter-satellite range of KBR system, range change and inter-satellite acceleration are determined, and that of the satellite position, velocity and accelerometer surveying data through satellite-borne GPS receiver. Then, the adjustment distance precision index between the quality center of accelerometer and satellite is calculated, and the measurement accuracy and stability of the star sensor in attitude angles measurement are analyzed. Besides, the influences of reference gravity model towards the accumulated geoid accuracy and the integral satellite orbit are calculated.(10)A calculation platform for earth's gravity field model recovery from satellite gravimety data is developed.