Assessment of an analytical expression for an evaporation duct refractivity profile

The prediction of radar coverage for systems operating within or near the Marine Surface Boundary Layer (MSBL) requires the knowledge of the vertical refractivity profile. This vertical profile and the corresponding evaporation duct height are generally computed by the means of semi-empirical “bulk” models. Nevertheless, for practical purposes, it could appear very useful to describe the refractivity profile with an analytical expression. The “classical” log-linear law that has been widely used during the past decades has recently been modified and improved. This paper discusses the ability of this new expression to match a physical “bulk” model. Our study concerns both simulated vertical profiles and some corresponding propagation results in X band.