Simulation and modeling of rainfall radar measurements for hydrological applications

A procedure is described for the simulation of rainfall radar reflectivity (absolute and differential) measurements by dual linear polarization meteorological radars. The basic requirement that the proposed procedure aims at satisfying is that radar data obtained at the end of the process be correlated in a physically plausible manner to the rainfall field at ground, the latter being generated by means of a stochastic space-time rainfall model. The main goal of the model is to give the possibility to easily check the accuracy of radar rainfall estimates derived by means of procedures and algorithms aimed at minimizing or compensating for the effects of measurement errors associated with several types of meteorological events, with particular reference to requirements of hydrogeological forecast systems. Within the limits imposed by the validity of the adopted model, an analysis was carried out indicating general criteria that may be adopted to achieve a better accuracy in rainfall estimates and a full exploitation of the advantages offered by the radar dual polarization measurement technique.