Rain/no-rain discrimination for TRMM precipitation radar

An algorithm for discrimination whether rain exists or not in the TRMM PR (Precipitation Radar) data is being developed. The rain/no-rain discrimination will provide us with useful information for on-line data processing, data storage control, and data analysis in post processing. A simple rain/no-rain discrimination with a flag output representing the possibility of rain is employed. The flag expresses the three states of rain as 'rain certain', 'rain possible', and 'rain little' at each PR footprint. Rain top height is also determined in this algorithm. The algorithm described here is implemented as one of TRMM standard algorithms.