The sun’s radiation activity has a decisive influence on the reflection ability of the ionosphere and thus on the spatial diffusion of short waves. Visible sunspots (see NASA picture on the left) reliably reflect the sun’s activity. An increase in number and size indicates greater solar activity. More radiation reaches the earth and the upper frequency limit of the reflected short waves rises. As a result, a wider range of the short wave spectrum can be used.
The relative number of sunspots is an important parameter for calculating the frequency forecast. SE-430-users will find the current charging file SE-430 under the ‘Current forecast’ link on the left. The source of the data is indicated on the data sheets.
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