ABSTRACT
The frequencies of the communication, navigation, and remote sensing applications treated in this book range all the way from extremely low frequencies (ELF) to microwaves. The mathematics of electromagnetic wave propagation in stratified media is very complicated, and progress in propagation theory in the early 1900s was fairly slow. The mathematical theory of electromagnetic wave propagation is based on Maxwell's equations, formulated by James Clerk Maxwell in the 1860s. Experimental propagation studies in free space and over the earth also go back over 100 years. Research in radio science, standards, and measurements began in National Bureau of Standards (NBS) in the early 1900s, and the long history of radio in NBS has been thoroughly covered by Snyder and Bragaw. Central Radio Propagation Laboratory (CRPL) was moved to Boulder in 1954, and Wait joined the organization in 1955.
