A Forward-Transmission Echo-Ranging System

A new type of echo-ranging system is described in which the receiver is located at a distance from the transmitter. It is shown that, with a configuration of this type, the range of the target with respect to the receiving station is equal to the difference in path between the direct and reflected waves divided by the versine of the angle of elevation of the receiving antenna (p = δ/1-cos θ). By making the radial writing speed proportional to this function, a PPI presentation system can be realized which shows a profile of the propagation path viewed from the side. This system has particular application in detecting targets such as, for example, atmospheric irregularities, which have a low reflection coefficient at normal incident angles. The system, therefore, promises to be useful in the study of propagation problems.