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Methodology for obtaining physical parameters from fully polarimetric coherent weather radar data: A first approach to unsupervised Entropy-Alpha-classification. Dr. Thomas Börner DLR Oberpfaffenhofen Microwaves and Radar Institute D-82234 Weßling. Outline.
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Methodology for obtaining physical parameters from fully polarimetric coherent weather radar data: A first approach to unsupervised Entropy-Alpha-classification Dr. Thomas Börner DLR Oberpfaffenhofen Microwaves and Radar Institute D-82234 Weßling
Outline • Introduction to the H-a decomposition theorem • Classification scheme • Analysis and interpretation of the polarimetric time series data set • Conclusions • Future activities
a = 0 a = 45 a = 90 What does a tell us?
“Classic” Products Zyy [dBZ] ZDR [dB]
Extracted Products Entropy H a angle [deg]
Zyy and Classification Zyy [dBZ] Classes
15 consecutive PPI Sector Scans Zyy [dBZ] Classes
Conclusions • It has been shown that it is possible to apply the H-a decomposition to polarimetric weather radar data and to retrieve meaningful results. • The classification provides knowledge about different types of scatterers without having to access empirical a-priori knowledge. • Proper interpretation of PPI scans is difficult, because it is unclear what the radar beam is actually scanning. • Regions with ground clutter can be easily detected, which might help to enhance clutter filtering.
Future Activities • Analyse RHI scans: different layers are easier to distinguish enhance the classification scheme! • Compare results with other sources of information about particles, preferably simultaneously collected. • Compare results with other classification methods. • Use additional parameters as l1 or the anisotropy to refine the classification scheme.