Modelling evaporation duct effects on microwave propagation with experiment validation

Microwave propagation is adversely affected by evaporation duct, which can occur as often as 85% of the time in the sea of the world. Evaporation duct propagation is the abnormal bending and diversion of electromagnetic radiation from the intended paths, that resulting in the problems of extended propagation of microwave signals well beyond the radio horizon, radar holes, and anomalous clutter. This paper describes a software package, evaporation duct propagation-parabolic equation (EDP-PE), a MATLAB-based implementation of the parabolic equation(PE).The EDP-PE provides a PE solution for propagation loss in the inhomogeneous atmosphere and the rough sea surface, which is more useful in the coastal regions where topographically-induced changes in refractive index profiles are common place. To validate the purposes the paper shows a comparison between EDP-PE calculations and the measurements. The calculated path loss for several evaporation duct profiles shows an excellent agreement with the measurement. Coverage diagram examples presented serve to illustrate the complicated nature of the propagation patterns which arise from evaporation ducting layers.