Modeling evaporation duct based on pseudo-refractivity and its comparisons with direct measurement results [radio-wave propagation]

In this paper, the theoretical method used for calculating evaporation ducts and its comparisons with direct measurements of evaporation ducts are described. The theoretical method of modeling evaporation ducts is based on planetary boundary layer theory with pseudo-refractivity N_p as a similarity variable. With the approximation of refractivity independent of air pressure in the vicinity of the sea surface, a parameter, the pseudo-refractivity N_p(h), as we call it, is defined. The M profile of evaporation ducts, which is always not available in references, is given explicitly. An evaporation duct profile is measured with a microwave refractometer, and the experiment is described. The modeling results of evaporation duct profiles from the measured weather data are compared with the direct measurement results.