Sky Wave Propagation at Medium and High Frequencies

In this article, we shall discuss the following topics: 1. Basic physical properties of sky wave propagation (namely, refraction, reflection, penetration, and absorption) 2. relationships between vertical propagation and oblique propagation 3. ionospheric models 4. characteristics of medium frequencies 5. characteristics of high frequencies 6. prediction programs for ionospheric sky wave performance 7. real-time channel evaluation Keywords: ionosphere; sky wave propagation; medium frequency; high frequency; broadcasting; point-to-point communications