ELECTROMAGNETIC FIELDS OF AN OSCILLATING MAGNETIC DIPOLE OVER AN ANISOTROPIC EARTH

Abstract

The problem of electromagnetic wave propagation from an oscillating magnetic dipole placed over a uniaxially anisotropic earth has been considered. Formal expressions for the vector potentials inside the earth have been derived. It has been shown that for a vertical magnetic dipole, the field components are identical to those in the case of an isotropic medium in which the conductivity is the “horizontal or longitudinal conductivity.” For a horizontal dipole, directed along the x axis, it has been shown that the vector potential inside the earth will have a y component as well as x and z components. Formal expressions for the vector potentials in air have been obtained for the case of a horizontal magnetic dipole. However when the conductivity of air is considered to be negligibly small, the field components are not affected by the anisotropy.