Geophysical Journal | 2003 volume 25 3

Field sources and electrodynamic features of the material media and electromagnetic sounding systems: applied aspect

© Shuman V.N.

The methods and results of asymptotic presentations of accurate solutions of 1-D boundary value problems of geoelectrics with controlled field excitation of different type, obtained by the method of eigenfunctions and integral transformations are discussed. A great attention is given to heuristic approaches with invoking different geophysical ideas, in particular to the ray method, methods of asymptotic disturbances of the fundamental solution and equivalent mirror reflections. The problem of the correspondence of the excitation type and the excited field type urgent for application is analyzed. The incompleteness and limitation of the physical presentations used for describing the process of the interaction of electromagnetic fields of elementary sources with a geologic medium are noted. Thus, the classical analysis, identification of the fronts of a totality of direct, converted, diving waves and those directed by adiscontinuity are a much more complicated problem than that assumed earlier. Some possibilities of describing interaction of the electromagnetic field with the polarizing and magnetizing medium in a high-frequency range based on the Maxwell equations system containing the vector of the generalized electric induction are discussed.

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