Study on the Basic Matters of EM Explorations System Using Electromagnetic Field Analysis

摘要

TDEM method is a popular used method in exploration geophysics. The method detects the underground resistivity structures by analyzing the transient phenomena of the EM field occurred when the source current is rapidly shut out. A problem that we often embarrassed is that the above surface measurements failed to detect the structures in the depth in case that the near surface layer were conductive. To solve this problem EM tomography measuring system is suggested, which, by putting the sensor through borehole into the subsurface, extended our measuring domain from two to three dimension. This is a leading edge in this field under its developing way.