Toward a physically-based identification of vertical profiles of reflectivity from volume scan radar data

A method for identifying VPRs from volumetric radar data is presented that takes into account radar sampling. Physically-based constraints are introduced with a simple VPR model so as to provide a physical description of the vertical structure of rainfall over time-varying geographic domains in which the type of precipitation is homogeneous. The model parameters are identified in the framework of an extended Kalman filter, which ensures their temporal consistency. The method is assessed using the dataset from a volume-scanning strategy for radar quantitative precipitation estimation designed in 2002 for the Bollene radar (France). Positive results have been obtained; the physically-based identified VPRs: (i) present physically consistent shapes and characteristics considering beam effects, (ii) show improved robustness in the difficult radar measurement context of the Cevennes-Vivarais region, and (iii) provide consistent physical insight into the rainfield.