Propagation Of Elf And Vlf Waves Near The Earth

This volume is based on lectures and discussions presented at a NATO Advanced Study Institute on ELF and VLF Radio Wave Propagation, which was held in Norway April 1974. The study of propagation of electromagnetic waves with frequen cies below 100 kHz has long traditions in ionospheric physics. To-day, this frequency range is still of great importance, both to the physicist, who uses the waves as diagnostic tools to study the earth's environment and to the engineer who exploits the characteris tics of these waves to improve communications, navigation and timing systems. In recent years the active interest in the field has led to very rapid progress in the development of propagation theory as well as in the application of this theory to the solution of practical problems. The intention of the Organizing Committee for this Conference was to bring together theoreticians and experi mentalists working on the various aspects of wave propagation, in order to stimulate a fruitful discussion and exchange of ideas.

Terrestrial Propagation of Long Electromagnetic Waves deals with the propagation of long electromagnetic waves confined principally to the shell between the earth and the ionosphere, known as the terrestrial waveguide. The discussion is limited to steady-state solutions in a waveguide that is uniform in the direction of propagation. Wave propagation is characterized almost exclusively by mode theory. The mathematics are developed only for sources at the ground surface or within the waveguide, including artificial sources as well as lightning discharges. This volume is comprised of nine chapters and begins with an introduction to the fundamental concepts of wave propagation in a planar and curved isotropic waveguide. A number of examples are presented to illustrate the effects of an anisotropic ionosphere. The basic equations are summarized and plane-wave reflection from a dielectric interface is considered, along with the superposition of two obliquely incident plane waves. The properties of waveguide boundaries are implicitly represented by Fresnel reflection coefficients. Subsequent chapters focus on boundaries of the terrestrial guide; lightning discharges as a natural source of extremely-low-frequency and very-low-frequency radiation; and the mode theory for waves in an isotropic spherical shell. This book will be a useful resource for students and practitioners of physics.

This book deals with the SLF/ELF wave propagation, an important branch of electromagnetic theory. The SLF/ELF wave propagation theory is well applied in earthquake electromagnetic radiation, submarine communication, thunderstorm detection, and geophysical prospecting and diagnostics. The propagation of SLF/ELF electromagnetic waves is introduced in various media like the earth-ionospheric waveguide, ionospheric plasma, sea water, earth, and the boundary between two different media or the stratified media. Applications in the earthquake electromagnetic radiation and the submarine communications are also addressed. This book is intended for scientists and engineers in the fields of radio propagation and EM theory and applications. Prof. Pan is a professor at China Research Institute of Radiowave Propagation in Qingdao (China). Dr. Li is a professor at Zhejiang University in Hangzhou (China).