The teaching of propagation over flat and spherical surfaces

Propagation over flat and spherical surfaces is the practical basis of radiowave propagation. In each case the theoretical solution for the received field strength, where it is known, will depend on the transmitter power, the antenna power gain, the geometry of the propagation path, the ground constants, the refractive index variation over the air path and the frequency. A measure of uncertainty is associated with calculations alone, and they must be supplemented by a number of measurements. The purpose of this paper is to emphasise what can be calculated, so as to minimise the cost of experimental measurements. These calculations will relate to propagation over planar and spherical surfaces since it will be assumed that propagation in free space is understood