Magneto-telluric impedance: fundamental models and possibilities of their generalization
© Shuman V.N.
A problem of impedance description of magnetic field on the surface of heterogenic Earth is discussed in the article. The concepts of impedance tensor, Vise-Parkinson tensor, generalized impedance tensor, Leontovich's impedance approximation and its generalization are analyzed. It is noticed that these models are of particular character and are real only in cases of special forms of giving primary field and do not always correspond to conditions of conducting real magneto-telluric experiment. Generalized system of vector identities of impedance type is given for harmonic electromagnetic field on the closed interfaces and generated on their base generalized accurate differential equation of impedances and the system of scalar equations which determine this surface. It is noticed that in case of necessity of using their incomplete, truncated forms these models in contrast to classical ones, have interior criteria of their application and do not demand for their substantiation any additional empirical or heuristic considerations.