Diversity effect on VHF space communications

The signals in VHF space communications fluctuate rapidly on the propagational path through the turbulent ionosphere, and fading is of Rayleigh distribution, if circularly polarized waves are received. The diversity effect on VHF communications between an earth station and a satellite in a stationary orbit is about 10 to 20 dB, where transmitted linearly polarized waves are received by the use of circular or linear polarization diversity, when fading exists. The polarization diversity reception is effective in diminishing the time when signals fade out, and it will be one of the best methods for more reliable VHF space communications through the turbulent ionosphere.