Three-dimensional Inversion Method Of Gravity Data

In recent years, with the rapid development of hardware equipment and the upgrading of the computer technology, gravity prospecting equipment precision and efficiency have improved a lot, also data processing and interpretation methods also interpreted by traditional semi quantitative gradually to quantitative interpretation. With the in-depth study of gravity data interpretation and inversion of two dimensional has been difficult to meet the finely defined the requirements of geological structure, so 3D inversion occasion and become an important research direction of inversion in recent years.Constitute the basic elements in based on gravity data in the inverse process, model structure system, the objective function and optimization method. Therefore, this paper based on gravity anomaly inversion theory, from the three elements of tested different model construction method, different objective function and different weighting factors to the inversion result influence.First, in semi underground space mesh, using two strategies: first is the uniform mesh points, half space partition into uniform vertical cuboid, the interval for decomposing a simple, relatively easy to operate; the second is non uniform meshes, because with the increase of the depth of, potential field data resolution down, so when the depth increases can appropriately increase the grid, which improves the calculation speed and the precision of the inversion has little effect.Secondly, the commonly used objective function is formed by the data constraint, constraint model and regularization factor, due to the different data constraints and model constraints Lianggang, regularization factor bear two functions of adjusting dimension and weight coefficient. As a result regularization factor is hard to determine, after the study, the amplitude or mean normalized and eliminate the dimension effect, the regularization factor is the role of weight coefficient, so in this case, the regularization factor known as the weight factor.Finally, the optimization method is selected by the trust region method. After the theoretical model test and the actual data processing of a certain mine in Jiangxi, this paper tests the validity and efficiency of the method.