Hydrometeor classification methodology for C-band polarimetric radars

Classification of hydrometeors has a wide variety of applications such as validation of cloud microphysical models, choice of algorithm for precipitation estimation and evaluation of assumptions made in the precipitation retrieval processes as well as validation of space borne observations. Dual-polarization radar measurements are sensitive to hydrometeors properties such as size, shape, phase state and fall behavior, they can be used for hydrometeor classification purposes. Over the last decade the topic of dual-polarization radar measurements to classify hydrometeors has been investigated extensively at S-band. Fuzzy logic based approaches to perform robust hydrometeor classification have emerged because of their ability to provide distinct decisions with overlapping conditions and noisy data. Essentially, two classes of independent models, for hydrometeor classification have evolved, namely the CSU model and the NCAR/NSSL model. Most of available literature on this topic is from S-band radar observations. Only recently, some work related to hydrometeor classification at C-band is being initiated. Adapting a hydrometer scheme devised for S-band to C-band measurements is not straightforward. Different backscattering and propagation properties, attenuation effects on radar observations should be taken into account in the classification scheme. This paper discusses issues related to advancing the CSU hydrometeor classification scheme for C-band frequencies. Results of preliminary development are presented.