Ionosphere
Posted: Mon Jul 12, 2004 1:50 pm
The ionosphere is a charged layer of the atmosphere that can reflect radio waves. Actually it is a series of layers from 30-275 miles in elevation. It enables communication beyond the horizon for a band of frequencies, and with multiple reflections can reach half way around the globe. What those frequencies are depends on the time of day, the time of year, and time within the 11-year sunspot cycle.
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