Retrieval of parameters of a horizontal hydrometeor distribution within the field of view of a satellite microwave radiometer

The information about variations in a small-scale horizontal hydrometeor distribution (HHD) within the microwave radiometers field of view (FOV) is necessary to subdue "beam-filling" errors in rainfall retrieval. The present study substantiates the potentiality and the method of the determination of some HHD parameters along with a footprint-averaged rainfall from spectral/polarization microwave radiometer measurements. HHD parameters selected for the retrieval provide an effective description of the HHD, and at the same time their variations are detectable and distinguishable from radiometer measurements. In addition, availability of the HHD parameters allows the interpretation of the procedure of screening rainless footprints as a detection of the rainfall signal on the background of the retrieval errors. The method is tested for available hydrometeor profile simulation and demonstrated with the example of tropical rainfall measuring mission microwave imager (TRMM TMI) measurements processing.