The ITS Irregular Terrain Model, version 1.2.2: The Algorithm

George A. Hufford

Abstract: This white paper documents the algorithm of the ITM (the Irregular Terrain Model) as implemented in 1999. There are probably, however, some features of the model that are not documented here but present in the original Fortran source code. The purpose of the model is to estimate some of the characteristics of a received signal level for a radio link. This usually means cumulative distributions for what really appears to be a random phenomenon. The original model was developed in the late 1960's when land mobile radio and television broadcasting were important systems that required better engineering. Perhaps that explains the emphasis on low and hidden antennas and on the long-distance fields that might cause interference.

Keywords: propagation prediction; Irregular Terrain Model (ITM)

(HuffordITMalgWhitePaper.pdf)

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