Radiowave Propagation in Communications was written with two basic objec­ tives: (l) to present an up-to-date review of the major radiowave propagation phenomena which hinder reliable space communications, and (2) to describe how these propagation phenomena affect the design and performance of satellite communications systems. Earth-orbiting satellites are employed extensively for the relay of information in a vast array of telecommunications, meteorological, government, and sci­ entific applications. Satellite systems rely on the transmission of radiowaves to and from the satellite and are dependent on the propagation characteristics of the transmission path, primarily the earth's atmosphere. Radiowave propagation thus plays a very important part in the design and ultimate performance of space communications systems. This book presents, for the first time, the meshing in a single publication of the fundamentals of radiowave propagation factors with a discussion of the practical consequences of these factors on satellite communications systems. Two major subfie1ds are involved in this book. Radiowave propagation, which is basically applied electromagnetic theory, provides the theory and an­ alytical tools for the first several chapters. Later chapters then apply propagation effects to the field of electrical engineering involved with satellite communications. The material progresses from the essential aspects of radiowave prop­ agation to the application of practical methods and techniques in the design and performance of satellite communications systems.