Electromagnetic field of the ground-based source surrounded by a plasma semispheroid

Radiophysical Research Institute, St. Petersburg University, St. Petersburg, Russia

Abstract

[1]  Currently, in geophysics, there is growing interest about the deep layers of the Earth. Information about these layers may be obtained from analysis of the electromagnetic field at relatively low frequencies. Low-frequency antennas are usually very cumbersome. One aim is creation of an antenna that would be effective at low frequencies and compact enough. To do this, electromagnetic fields of ground-based sources in the presence of a plasma coating are studied. Such problems for the well-conducting Earth's surface are solved approximately using the equivalent theorem. This makes it possible to find the field at any distance from the source, including the Earth's surface. For a coating in the form of a two-layer plasma semispheroid, the solution is looked for in spheroidal functions attracting the theorem of addition. The influence of a plasma coating of high curvature is analyzed in the quasi-static approximation.

Received 7 April 2005; revised 17 August 2006; accepted 24 August 2006; published 14 December 2006.

Keywords: Earth's surface; Plasma; Resonance.

Index Terms: 2499 Ionosphere: General or miscellaneous; 2443 Ionosphere: Midlatitude ionosphere; 2427 Ionosphere: Ionosphere/atmosphere interactions.