Based on Cauchy criteria, the regularized sparse inversion can be made by using pre-conditional conjugate gradient algorithm (PCGA) in simultaneously iterative inversion of reflection factor and wavelet.

However,two-dimensional inversion of EH-4 data has a problem.

Considering the influence of the topography, the authors analyzed in detail the geoelectric section model and made CSAMT two-dimensional inversion for the direct calculation data of the model.

: In order to enhance the capacity of data inversion in the electrical method and to find out a better inversion method, we have introduced and developed the Box-Kanemasu method successfully in this paper in addition to studying the application of the modified damping least-square method in a two-dimensional inversion.

The 2 D inversion is the best method in the interpretation of DC resistivity sounding profiles data owing to its high speed, but the 3 D inversion, by contrast, needs more measured data and more computer time.