Propagation of Waves focuses on the wave propagation around the earth, which is influenced by its curvature, surface irregularities, and by passage through atmospheric layers that may be refracting, absorbing, or ionized. This book begins by outlining the behavior of waves in the various media and at their interfaces, which simplifies the basic phenomena, such as absorption, refraction, reflection, and interference. Applications to the case of the terrestrial sphere are also discussed as a natural generalization. Following the deliberation on the diffraction of the "ground wave around the earth, this text summarizes the role and properties of the troposphere and ionosphere from a general physical point of view. Examples and maps are provided to illustrate the use of the various methods in the determination of ranges or favorable wavelengths. A brief discussion on problems encountered in the field of space communications is also included. This publication is a good source for students and individuals researching on wave propagation, specifically on the principles of radiation and propagation in a homogeneous, isotropy, and lossless dielectric.