Approximation of Regional Gravity Fields from Multi-Scale Data
In this paper, a framework for the multiresolution approximation of regional gravity fields is formulated. Two estimation approaches, one in the signal domain, the other in the measurement domain, are then developed. In this framework, the estimation of a gravity field signal is done based on all available data, taking into account different resolutions from the coarsest scale to the finest scale. A discrete wavelet transform or a multirate system are used as a bridge, effectively linking different resolution levels. To validate the proposed framework, both methods have been programmed and applied to different scenarios. Two of them are briefly discussed in this paper. Results show a reduction of errors for the multiscale solution when compared to a solution with one scale only. From an operational point of view, the measurement domain approach currently offers greater flexibility in handling non-integer scale ratios.
KeywordsGravity Field Discrete Wavelet Coarse Scale Resolution Level Satellite Altimetry
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