2D inversion of resistivity sounding based on partial derivative and statistics
Cheng Bo1,2, Di Qingyun1
1. Key Laboratory of Engineering Geomechanics,Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China;
2. Graduate University of Chinese Academy of Sciences,Beijing 100049,China
Abstract：In order to obtain detaHs of inversion results, a new inversion method based on partial derivative and statistics for VES is proposed.The inversion would be carried out in two steps.The first step is to judge the electrical structure of a stratum by statistics and partial derivative, and to define the target location.An initial model of the stratum structure is buiit on partial derivative of the stratum parameters and statistics of ID inversion.The second step is to modify the parameters by genetic algorithm and finite element stimulation to decrease fit errors.The advantage of this method is that the initial model for inversion is similar to the actual target, and there is no need to calculate large linear equations, so the calculation amount is much lower.The total fit error and the local fit error caused by anomalies are separately calculated during the inversion to direct the variation.The inversion resuit is visual.Theoretical model and real data experimental tests demonstrate the effectiveness of the method.