Study the Impact of the Distance Factor on the Optimal Workable Frequencies for the Long Distance Radio Communications

Abstract

In this research, the influence of the distance factor on the optimal working
frequency (FOT) parameter has been studied theoretically for the ionosphere layer
over the Middle East Zone. The datasets of the (FOT) parameter have been
generated using the (VOACAP) model which considers as one of the recommended
modern international communication models that used to calculate the ionosphere
parameters. The calculations have been made for the connection links between the
capital Baghdad and many other locations that distributed on different distances and
directions over the Middle East region. The years (2011-2013) of the solar cycle 24
have been adopted to study the influence of the distance factor on the FOT
parameter. The results of the conducted study showed that the distance factor has a
clear influence on the values of the FOT parameter, also the day/night effect is more
significant in the long distance HF links (i.e. more than a 500 Km).