An Adaptive Rainfall Estimation Algorithm for Dual-Polarization Radar

Dual-polarization radar provides information about precipitation microphysics through drop size distribution and hydrometeor classification, and, therefore, can produce improvement in quantitative precipitation estimation. Rainfall relations combination is an optimization algorithm; however, optimally selecting the rainfall relation is challenging in dual-polarization rainfall estimation. In this study, an adaptive rainfall algorithm is developed using a logistic regression model to guide the choice of the optimal radar rainfall relation. The logistic model is established according to the matched dual-polarization radar data and rain gauge data. Only liquid particles are considered for the rainfall estimation determined by the hydrometeor classification of dual-polarization radar, and the polarimetric rainfall relations are obtained with a neural network algorithm based on the disdrometer data. The proposed algorithm is validated with C-band dual-polarization radar data, and the results show that the adaptive algorithm outperforms the single rainfall relation and conventional combination algorithm.