A Hybrid Prediction Model for Propagation over Irregular Terrain in the VHF and UHF Bands

This paper proposes a hybrid model for the calculation of diffraction by terrain irregularities in the VHF and UHF bands. The model is based on the theories of diffraction by multiple obstacles and over a smooth spherical earth. It includes also an interpolation procedure to solve the problem in the transition between these two solutions. A MATLAB tool was employed for testing the proposed hybrid model by comparison with 8934 measurements available in the ITU-R (Radiocommunication Sector of ITU) data bank. It has shown a RMS error at least 3 dB smaller than other models developed for the same purpose.