Comparison of resolution of various types of electromagnetic soundings

Different types of electromagnetic soundings are characterized by different investigation depth, productivity and resolution. For estimation of their resolution capability the curves of residual functions are used. Model calculation are shown that transient EM soundings (used near-field zone) posses the maximal accuracy of 1D geoelectric sections parameters assessment. Slightly worse are MT soundings. Resistivity soundings with symmetric offset are adequate for investigation only of over-shielded sections. As for differentially normalized parameters, they are relatively cruder instrument of resistivity evaluation. Even in the class of polarized strata simple EM curves, calculated with geometry and current normalization are sufficiently better resolved in comparison with DN-parameters.