Rain profiling algorithm for TRMM Precipitation Radar data Original Research Article

This paper describes the TRMM standard algorithm 2A25 which estimates the instantaneous vertical profile of rain from Precipitation Radar (PR) data. Major challenges in rain profilling from the TRMM PR lie in the corrections for the effects of rain attenuation and non-uniform beam filling (NUBF) and in the rejection of surface clutter. A combination of the Hitschfeld-Bordan and surface reference methods is used to correct the attenuation effect in radar returns. The NUBF effects are estimated from the spatial variations of the estimated total path integral of attenuation from the top of the rain to the surface in the vicinity of the radar beam concerned. This paper outlines the critical part of the algorithm, and shows some results of comparisons of data taken nearly simultaneously by the TRMM PR and a ground-based radar.