Prediction and calculation of transmission loss in different types of terrain

A model for the calculation of transmission loss in the VHF and UHF regions has been developed. It has been used in service area predictions in different types of irregular terrain in Sweden with much better results than the existing models. The method is very easy to handle and needs no complicated computer technique. It takes proper account of the ground dielectric constant and the terrain profile including vegetation. It is thus a deterministic model giving the long-term median of the basic transmission loss. In planning terrestrial radio systems it is also necessary to have a knowledge of the variability in time and with location. On that account measurements are presented giving the additional loss for various percentages of time and locations. The best possible use of the capacity of telecommunication systems is often limited by the depolarization produced by absorption and scattering in the terrain. The effect of depolarization is given for various percentages of locations.