HF signal fading may not always be Rayleigh: both fading and transmission loss are greatly influenced by practical transmitting and receiving antennas

摘要

The author discusses HF broadcasting and HF propagation. The short-term fading of HF signals, i.e. fading within the hour is examined because the data available is only applicable to that variable. It is also a logical starting point. Two interrelated variables are examined, antenna performance and ground loss. The gain of all practical antennas varies with elevation angle and is asymptotic to zero at zero degrees of elevation. Ground loss also varies with elevation angle and with the properties of the ground. The interrelationship of these effects is examined.