Some ionosphere scatter techniques

This paper discusses three possible applications of ionospheric scatter which are useful to the high frequency communicator. The first of these involves the use of backscatter to determine the zone of communication for a certain frequency when utilizing normal innosphere modes of propagation. Normal modes are those in which the layer is sufficiently ionized to allow a direct ray to be propagated from the transmitting station to the receiving station via the ionosphere. The second also involves the use of backscatter but in a sense that the intelligence is actually carried from the transmitter to the receiver by way of the backscattered rays from a distant point not necessarily on the great circle path between the stations. Such a technique can often be applied when the frequency to be used is above the maximum usable frequency for the path. The third technique makes use of actual scattering within the layer so that a small amount of energy may be returned to many possible receiving pointseven though most of it is lost into space. Each of these three applications of scatter will be considered separately.