Skriv i debatforum
Annuller indlæg
Grå linje... OD123 16. januar 2013 kl. 19:54.
God info for dem der ikke ved det..... The grey line is a band around the Earth that separates the daylight from darkness. Radio propagation along the grey line is very efficient. One major reason for this is that the D layer, which absorbs HF signals, disappears rapidly on the sunset side of the grey line, and it has not yet built upon the sunrise side. Ham radio operators and shortwave listeners can optimize long distance communications to various areas of the world by monitoring this area as it moves around the globe. This map shows the current position of the grey line terminator.
kik map her...
http://dx.qsl.net/propagation/greyline.html |