Choice of a suitable method for the prediction of the field strength in planning land mobile radio systems

Aiming at the choice of a method for the field strength prediction over irregular terrain in land mobile radio service which could be adopted as the most suitable for engineering purposes, six out of the known methods have been analyzed. To verify their prediction accuracy, complex field tests have been carried out. With the moving vehicle, the field strength has been measured along well defined path profiles. Statistical processing of the recorded data has yielded the median field strength levels in a number of points of the path serving as reference for the accuracy assessment. Other features of the compared methods, such as their operativeness, complexity, suitability for the computer application, influence of subjective factors, and tolerances in determining the initial data, have been discussed. The "clearance angle" method, recently proposed and experimentally verified in detail during the field test described in this paper, has been chosen, after an argued analysis, as the most suitable field strength prediction method for engineering purposes.