Radar parameters calculations for Γ distribution of cloud particles in single scattering approximation

A code developed by Mishchenko based on T-matrix approach has been modified. In addition to the single scattering evaluations of C(ext), C(sca), C(abs), w (albedo), < cos q > (asymmetry parameter) and the non-zero elements of Mueller matrix at different scattering angles, we can now estimate a set of parameters which are even more useful to radar applications: backscattering cross section, attenuation coefficient, reflectivity Z (expressed in dBZ), IW C and LW C, either for ice or water clouds. Hydrometeor's models shapes can be spheroids (prolate/oblate) and Chebyshev particles (even order). The calculations are made at different frequencies (78, 94 and 125 GHz). It's possible to choose different kinds of size distributions (most used are a modified Gamma and a power law Hansen and Travis). Backscattering cross sections have been compared with a simplified code developed for validation. Reflectivity and IWC/LWC detections have been compared with semi empirical laws derived by direct measurements. Calculations have been made for five different types of cloud models, assumed as statistically uniform ensembles. Results have shown that reflectivity Z is quite independent of frequency for all the models which are not far from Rayleigh approach. Sizes have strong influence on results, while shapes are not determinant. Further aims are the investigations on depolarizations parameters, the construction of cumulative curves to define detectability of radar systems and the study of output sensitivity on size distributions parameters.