Accuracy Analysis of the Millington's Prediction Method in the Medium Waveband

Millington's field strength prediction method is analyzed under different simulation conditions on the basis of the results of a medium waveband (MW or medium wave band extends from 530 to 1600 kHz) digital radio mondiale (DRM) measurement campaign. Millington technique applies the reciprocity condition by simply averaging the forward and reverse field strength values. This simplified approach could be a source of field strength prediction error in the MW planning tools. Critical path features for the fulfillment of the reciprocity condition are identified and their influence on predicted values is stated. Reciprocity effect on the predictions error is evaluated by means of the difference between digital medium wave field strength measured values of certain critical selected paths, and the corresponding Millington's method predicted ones. It has been found that the prediction error can be as high as 15 dB when comparing Millington's method results and measurements but the simple reciprocity approach made by Millington procedure is not the most remarkable source of error.