An experimental investigation of the propagation of radiation having wavelengths of 2 and 3 metres

The paper describes the results of an experimental investigation of the characteristics within optical range of the propagation over land of radiation having wavelengths of 2 and 3 metres. It is shown both theoretically and experimentally that for such conditions the propagation of horizontally and vertically polarized waves is identical over a range of transmitter and receiver heights which are small compared with the distance between transmitter and receiver but not small compared with the wavelength. In these circumstances, for a receiver at height hR metres the field strength in volts per metre at a distance d metres from a half-wavelength radiator at a height hr metres is given by ¿ = 90¿PhThR/¿d2 in which P is the power (watts) radiated at a wavelength ¿ (metres). Continuous observations of field strength showed that within optical range of the transmitter the fading was less than ±3 db.