Effective Skin Depth of Whole EM Field Due to a Grounded Wire Source

The effective skin depth of whole electromagnetic filed due to a grounded wire source over a homogeneous half-space was defined as the depth at which the amplitude fall to 1/e of their value at the surface. With the closed form expression of EM fields generated by a grounded horizontal harmonic electric dipole in a homogeneous half-space, effective skin depth of different EM components were calculated and their variations with different parameters were studied as well. It depicts that effective skin depth due to grounded wire source depends on frequency, offset, conductivity and field components. But all the curves show similar characteristic variation, and the effective skin depth approach to plane wave skin depth at some certain value for all parameters. A theoretical example demonstrates that the effective skin dept can be used as one of effective aids for estimating the optimum parameters in EM survey design and data interpretations.