The Propagation of Radio Waves


Book Description

This book is concerned with the ionosphere and the magnetosphere, and the theory of their effect on radio waves. It includes accounts of some mathematical topics now widely used in this study, particularly W. K. B. approximations, Airy integral functions and integration by steepest descents. The subject is divided into ray theory and full wave theory. Ray theory is useful for high frequencies when the ionosphere is treated as a horizonally stratified medium. The discussion of the magnetosphere, whose structure is more complicated, includes an account of whistlers and ion cyclotron whistlers. The book has been planned both for final year undergraduates and as a reference book for research. It is suitable as a course book on radio propagation for students of physics or electrical engineering or mathematics. Some of the topics are presented from an elementary viewpoint so as to help undergraduates new to the subject. The later parts are more advanced. Because the subject is so large and has seen many important recent advances, some topics have had to be treated briefly, but there is a full bibliography with about 600 references.




Terrestrial Radio Waves


Book Description




Ionospheric Radio


Book Description

This introductory text replaces two earlier publications (Davies 1965, 1969). Among the topics: characteristics of waves and plasma, the solar-terrestrial system, the Appleton formula, radio soundings of the ionosphere, morphology of the ionosphere, oblique propagation, importance of amplitude and phase, earth-space propagation. Annotation copyrighted by Book News, Inc., Portland, OR







Terrestrial Propagation of Long Electromagnetic Waves


Book Description

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.







NBS Technical Note


Book Description







VLF Radio Engineering


Book Description

Electromagnetic Waves, Volume 14: VLF Radio Engineering provides a detailed coverage of the fields involved in very low frequency (VLF) radio engineering. This book serves as a guide for applying the information in the solution of practical problems. Comprised of seven chapters, this volume starts with an overview of the communications aspect following the flow of information carrying energy from the transmitting to receiving locations. This text then presents the complete systems that consider the interrelationship of the various factors. Other chapters explain the basic concept of a VLF antenna, which is a vertical electric monopole over a perfectly conducting flat plane. This book discusses as well the radio wave propagation at VLF, which has been studied theoretically and experimentally for many years. The final chapter deals with the primary components of a complete VLF radio system. This book is a valuable resource for radio engineers, scientists, and researchers.




Theoretical LF, VLF Field Calculations with Spherical Wave Functions of Integer Order


Book Description

The propagation of LF and VLF terrestrial radio waves is simulated on the computer with a precise theory of spherical wave functions of integer order. Anisotropic reflections from an electron and ion density profile of the ionosphere are accommodated by the analysis. Variations in the profile and the magnetic field with distance along the propagation path can be introduced ad hoc. The analysis method is incorporated into a computer program which is written in a flexible manner so that it can be applied to a variety of scientific studies of low-frequency ionospheric wave propagation. Calculations of current interest are presented to illustrate use of the technique. Amplitude perturbations of approximately 15 decibels are described at 60 kHz as a result of an electron density profile perturbation. It is also found that the 26 kHz signal is comparatively insensitive to a variation in magnetic dip angle when propagation occurs in the daytime near the magnetic equator. Thus, using values of the magnetic field vector at the center of the propagation path is a good approximation in certain circumstances.