On Upward Migration of Electromagnetic Fields in a Conducting Half-Space

Abstract

We outline the analytical basis of a scheme to excite a specified geometric form of the sub-surface field from the surface of a conducting half-space. The inversion or migration process is exact for the azimuthally symmetric model assumed. The numerical integration to determine the surface aperture field is straightforward. It is shown that, if the sub-surface field is too limited in lateral extent, the required aperture field distribution has a severe oscillatory character.