1-D inversion of surface-to-borehole TEM data based on grounded wire source

The surface-to-borehole TEM method has shown great potential in detecting deep minerals. This configuration mostly uses rectangular loops as its source. Considering the advantages of grounded wire sources in EM exploration, which had been successfully applied in ground and marine EM methods, we propose a new surface-to-borehole TEM system that utilizes a grounded wire source with relative short offsets. The 1D inversion of surface and borehole data was realized according to an OCCAM's inversion scheme. The inversion results of synthetic data indicates that only inversion of surface or borehole data will lead to resolution loss in deep or shallow earth. However, joint inversion of both surface and borehole data is an effective way to improve the results obtained from the inversions of individual data sets.