Multi-Spectral Classification of Hydrometeors Using AMSU-B Data

Abstract: The Advanced Microwave Sounding Unit-B (AMSU-B), flying on the NOAA-15, 16, and 17 satellites, is the new generation of a series of microwave imagers/sounders that can sense atmospheric moisture and other hydrometeors through clouds. This paper demonstrates the potential of multi-frequency AMSU-B data for classifying different types of hydrometeors. Ten of these classes have been found using data (station report, radiosonde, and infrared and water vapour images) over Iran. Co-located AMSU-B data are used to perform a quantitative classification of these meteorological situations. Three main classes, heavy precipitating, moderate precipitating, and non-precipitating hydrometeors are found based on the multi-frequency brightness temperature signatures. The results suggest that the signatures of precipitating and non-precipitating hydrometeors are sufficiently reliable. The distinguishing points, for this type of analysis, are: (a) brightness temperature at 89 GHz, (b) slops between 89 and 150 GHz and (c) cross over of brightness temperature curves at 183 GHz with respect to 89 GHz.