Estimation of Evaporation Duct and Surface-Based Duct Parameters from a Combined Refractivity Model

The study of atmospheric refractive conditions is essential in the shipboard radars and radio communication conditions in the maritime environment. Especially at low altitudes, as radio refractivity can vary considerably with both height and range, characterizing marine atmospheric boundary layer properties, ducting in particular, is thus crucial for air-sea interaction research. This paper proposes a novel refractivity profile model and describes a way to estimate parameters defining both evaporation duct and surface-based duct using the measured one-way propagation loss from a receiving X-band array at multiple range. The data was measured during the CASPER-West at-sea experimental campaign, which was conducted off the coast of Point Mugu, CA, during October-November of 2017.