3D constrained inversion of gravity data based on the Extrapolation Tikhonov regularization algorithm

In the process of the inversion of gravity data, as its solution is ill-posed, a new and stable method for controlling the convergence of computation named extrapolation of the Tikhonov regularization method has been used in the process of the 3D constrained inversion of gravity data to deal with the unstable solution. The error from the regularization parameter introduction in the inversion results reduced greatly. Details about the choosing of the principles based on three choose principles to calculate the Tikhonov regularization solutions were discussed. The model test results show that compared with the original Tikhonov method, the new method improves the fitting precision of the inversion. The depth weighting function improved by the author was applied to operate on the kernel function to counteract the quickly decaying with the depth. Comparing to the original function, the improved weighting function works better in identifying the density distribution of the bottom of the body. It has better effect in recognizing the deeper body than the former method. The upper and lower bound constraining method was employed to control the scope of the density contrast of each prism. The model gravity anomalies and the recovered gravity anomalies fitted well through the application of the algorithm and the produced density model represented the true structure well.