Hydrometeor classification from polarimetric radar measurements during STEPS

A fuzzy logic system for classification of hydrometeor type based on polarimetric radar measurements collected during the STEPS ( Severe Thunderstorm Electrification and Precipitation Study ) field experiment is described in this paper. During steps T-28 aircraft collected in-situ samples of hydrometeors and those measurements are used in the validation of the hydrometeor classification algorithm. In addition to application of hydrometeor classification scheme, sensitivity of the inferences to various polarimetric radar measurements are also studied, with the objective of obtaining the best classification with minimum number of observations. Preliminary results of the analysis indicates that when there is significant attenuation due to precipitation, specific differential propagation phase should be given maximum priority, whereas, in the absence of any attenuation, then linear depolarization ratio ( LDR ) and differential reflectivity ( Zdr ), in conjunction with reflectivity should be given the most priority. Results from STEPS will be used to demonstrate such and other inferences with in-situ validation for hydrometeor classification.