What is HF Wave Propagation?

HF Wave Propagation describes the behavior of radio signals at high frequencies (HF), typically in the range of 3-30 MHz. These waves can travel hundreds of kilometers, allowing for long-distance communication. The free electron density of the ionosphere influences the reflection of these radio waves. During the day, the ionosphere becomes more ionized, with higher frequencies reflected back to Earth. At night, it becomes less ionized, with lower frequencies reflected back to Earth. Extended explanations: An introduction to HF radio propagation, as well as scientific and technical concepts that you should be familiar with.

_{This project, "Understanding HF Propagation," provides radio amateurs with a detailed overview and tutorials on several aspects of HF propagation.}