Question

In communications
what is meant by the terms what does the atmosphere absorb power from waves propagating from it ? at what frequencies does this absoprtion become apparent

Answer 1

The power in the wire when once radiated into space through antenna converts into electromagnetic wave. These electromagnetic waves are attenuated by the atmosphere based on their frequencies. The atmospheric attenuation is nothing but decreasing the strength or power of the electromagnetic wave. The atmosphere absorbs energy of the electromagnetic wave by converting into atoms and molecules. The absorption is not significant at low frequencies which are below 10 GHz and it is more in some frequency ranges like 60 GHz to 120 GHz. There are also some high frequencies like 33 GHz and 110 GHz where absorption is significantly low. There frequencies are called windows.