Field strength prediction with a topographical data base: Experience gained in the Federal Republic of Germany

A topographical data base for field strength prediction, organized in area elements with a size of 5 x 5 km is described. The data stored for each area element are the maximum height above sea level and one of 10 figures describing the land morphology. The propagation prediction model is based on the empiriral correction factors and correction factors based on a large number of mobile measurements in the 450 MHz band which can be correlated with information stored in the data base. Measurement and prediction were compared, finding rather small mean errors. In small areas, however, the prediction errors may be large.