Abstract
This paper describes a novel single-frequency algorithm to estimate the vertical profiles of drop size distribution (DSD) of rainfall. The algorithm, which does not rely on the surface echoes, is proposed to be adopted in the TRMM precipitation radar (PR). The basic principle is to seek the DSD that can not only reproduce the radar reflectivity profiles at a given wavelength but also the path attenuation that is used for the constraints prior to deriving the DSD profile. The algorithm adjusts the estimate of attenuation factor at the surface iteratively until this estimate retrieves the reflectivity factor that is equal to the original measured reflectivity factor. The algorithm is applied to the spaceborne TRMM/PR radar data. The comparison between the results derived from the Hitschfeld-Bordan (HB) method, Surface Reference Technique (SRT), current TRMM method, and the proposed method is presented and discussed.
