Transmission of Electromagnetic Waves Through Normal and Disturbed Ionospheres


Book Description

The report presents the results of an analysis of the transmission of electromagnetic waves through the ionosphere. The objective of the calculations is to provide estimates of the propagation losses to be expected on communication links between satellites and the ground. A wide range of frequencies, 0.001 to 10 to the 10th power Hz, is considered, and normal and disturbed nighttime and daytime conditions are analyzed. The models and computational methods are summarized briefly in Section 2, extensive numerical results for the total transmission loss and height dependence of ionospheric attenuation are presented in Section 3, and the conclusions are given in Section 4. (Author).







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.




Wave Propagation in the Ionosphere


Book Description

In this book, the author draws on his broad experience to describe both the theory and the applications of wave propagations. The contents are presented in four parts and the sequence of these parts reflect the development of ionospheric and propagational research in areas such as space research geophysics and communications. The first part of the book presents an outline of the theory of electromagnetic waves propagating in a cold electron plasma. For reference, vector analysis, dyadics and eigenvalues introduced in this part are presented in the appendices. Practical aspects of radio wave propagation are the subject of the second part. The typical conditions in different frequency ranges are discussed and the irregular features of the ionospheric structure such as sound and gravity waves are also considered. Warm plasma and the effects of ions are considered in the third part, which includes a discussion of sound-like waves in electron and ion plasmas. Nonlinear effects and instabilities are described in the fourth part.




Scientific and Technical Aerospace Reports


Book Description

Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.




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.




Radio Waves in the Ionosphere


Book Description

First published in 1961, this book gives the full mathematical theory of the propagation of radio waves in the ionosphere and their reflection from it. It is complementary to J. A. Ratcliffe's books The Magneto-ionic Theory, which concentrates on the physical principles involved, since Dr Budden gives the mathematical development of many topics mentioned by Ratcliffe. The book will serve as a textbook for those comparatively new to the subject and as a reference book for practising engineers and research workers in the field of radio communication, for whom an understanding of the mathematical methods is important in solving practical problems.




Ionospheric Radio Propagation


Book Description







The Propagation of ELF Waves


Book Description

Theoretical analysis of the propagation of electromagnetic waves in the frequency range 30 Hz to 1000 Hz in the earth-ionosphere waveguide. Full wave methods incorporating the vertical inhomogeneity of the ionosphere are used. The model ionospheres, which correspond to both normal and disturbed (polar cap absorption - PCA) conditions, are chosen to illustrate the sensitivity of the propagation to various ionospheric properties. Attenuation constants and phase velocities pertinent to various models are calculated. In addition, detailed calculations of the height dependences of the electromagnetic fields and Joule heating are presented. Resulting conclusions are drawn as to which ionospheric properties and altitude regions most strongly influence the mode structure in the various cases. For example, it is concluded that ions always dominate ELF propagation under moderately disturbed (PCA) conditions, but under ambient conditions, ions are an important factor only for frequencies lower than a few hundred Hz. (Author).