Characterization of Rainfall/Cloud Signature Using Fully Polarimetric X-Band SAR Data

Applications of physical scattering models using fully polarimetric SAR data have demonstrated their use in several applications for Earth observation. In this paper, the authors demonstrate that the application of scattering powers derived from decomposition models is very useful in extracting information about the constituents of precipitating rain clouds. A hypothesis has been made that rain clouds consisting of ice particles would impart different scattering signatures compared to a water-only cloud. The detection of rain signature is identified by the normalized radar cross-section (backscattering) method as well as the ratio of individual scattering powers. However, additional information about the presence of ice particles in the rain cloud is detected by scattering powers derived from the latest seven-component scattering power decomposition (7SD) model. In addition to detecting the signature of rain clouds, fully polarimetric SAR data demonstrate the possibility of differentiating constituents of precipitating clouds. The presence of clouds and rain during polarimetric SAR data acquisitions and results of the study are further verified with optical data from Landsat 8 and ground-based weather data.