The Sun and HF radio propagation

A summary of the way in which the Sun affects ionospheric propagation (HF radio propagation) for two way radio communications, mobile radio communications, broadcasting, etc.

The Sun has an enormous impact on HF radio propagation because it affects the ionosphere which gives rise to most of the long distance effects that enable long distance radio communications on the HF bands. As a result is greatly affects many forms of radio communications from the typically two way radio communications systems that are sued by many organisations, and various forms of mobile radio communications using the HF bands to radio broadcasting, point to point radio communications and radio amateur transmissions. As a result, a knowledge of how the conditions on the Sun affect radio signal propagation is essential for radio planning and prediction HF propagation conditions. Radio propagation prediction software also takes the state of the Sun into consideration when it calculates its estimates of the propagation conditions.

To look at the way the Sun affects the ionosphere and radio propagation conditions, it is necessary to take a quick look at the various areas in the atmosphere to see which areas influence radio propagation and how the sun affects them. These factors are important in being able to predict propagation conditions and when using radio propagation prediction programmes.