Aerodynamic roughness retrieval from polarimetric ALOS-2 data in urban areas

Aerodynamic roughness is an important parameter for urban meteorological and climate studies. Buildings in urban areas alter the surface roughness and the drag effect of urban surfaces, which in turn affects urban boundary layer dynamics. Polarimetric Synthetic Aperture Radar is considered to be an effective means for aerodynamic roughness retrieval because polarimetric parameters are sensitive to the surface roughness and geometric structure of a given target. In this paper, the correlation between radar polarimetric parameters and aerodynamic roughness in urban areas are analyzed. And then the optimal polarimetric parameter for the aerodynamic roughness calculation was determined. Finally a quantitative relationship was set up to retrieve the aerodynamic roughness length in urban areas from polarimetric SAR data.