Frequencies in the UHF range normally propagate by means of: (a) Ground waves. (b) Sky waves. (c) Surface waves. (d) Space waves.
(d) Space waves An ultra high frequency (UHF)wave cannot travel down the ground's trajectory or be reflected by the ionosphere due to its high frequency. Line-of-sight communication, which is nothing more than space wave propagation, is used to transmit UHF signals
