Estimation of Hydrometeor Fall Velocity from ST Radar Spectrum using Bi-Gaussian Fitting and its Validation with Micro Rain Radar

A novel approach using Hybrid Bi-Gaussian fitting is developed and applied to ST Radar raw spectrum for the identification of clear air and rain echoes. The algorithm proved efficient in separating the echoes for all classes of rainfall which enables further computation of clear air vertical velocity and hydrometeor fall velocity from multi-peaked power spectra. The validity of this novel algorithm is established by comparing the profiles derived from adaptive fitting with that obtained using fall velocity directly obtained from Micro Rain Radar (MRR). In this study, the hydrometeor fall velocity derived from ST Radar rain echo after applying the adaptive hybrid fitting is validated against the fall velocity obtained from Micro Rain Radar(MRR) operating at 24.23 GHz. The vertical profiles of fall velocity derived from ST Radar spectrum compares well with that obtained from MRR during heavy and light rainfall intensities.