Talk:Ionosphere Layers

Radio Waves

H.F. (High Frequency 3 to 30MHz)

Long Range communications. Shipping, Aircraft, World Broadcast Communications, Radio Amateurs. Use involves reflecting the signal off the ionosphere back down to waiting recieving stations. Prone to atmospheric changes causing fading and noise. Range from 500 to thousands of Kilometres.

V.H.F. (Very High Frequency 30 - 300 MHz)

Medium range communications. Fleet vehicles, mobile, coastal shipping and air to tower communications. Range 70-100km (aircraft several hundred km).

U.H.F (Ultra High Frequency 300-3000 MHz)

This is the domain of such things as Police handheld radios, cell-phones, T.V., and spacecraft to ground communications. In the high U.H.F. range the signal can "bounce" off buildings and reflect until it is detected by a receiver.