Novel approximation for inverting the conductivity profile of pure conducting medium

For a half-space pure conducting medium, Ge and Chen (see IEEE Trans., vol.AP-39, no.7, p.907-9, 1991) have given an approximate formula in closed form, which can be used to directly invert the conductivity profile. Nevertheless, the reconstruction error is obvious. The authors derive a novel approximation by using electromagnetic wave theory, which is also in closed form. Reconstruction examples show that the novel approximation is more accurate than the original one.