Thomas.boerner@dlr.de, slide 1 German Aerospace CenterMicrowaves and Radar Institute Methodology for obtaining physical parameters from fully polarimetric.
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thomas.boerner@dlr.de, slide 1German Aerospace Center Microwaves and Radar Institute
Methodology for obtaining physical parameters from fully polarimetric
coherent weather radar data: A first approach to unsupervised
Entropy-Alpha-classification
Dr. Thomas BörnerDLR Oberpfaffenhofen
Microwaves and Radar InstituteD-82234 Weßling
thomas.boerner@dlr.de, slide 2German Aerospace Center Microwaves and Radar Institute
Outline
• Introduction to the H- decomposition theorem• Classification scheme• Analysis and interpretation of the polarimetric time
series data set• Conclusions• Future activities
thomas.boerner@dlr.de, slide 3German Aerospace Center Microwaves and Radar Institute
Decomposing the Scattering Matrix
yyyx
xyxxL SS
SSS TyyxyxxL SSSs 23
0
0
01
10
10
01
10
01
i
idcba
baidc
idcbaS
TxyyyxxyyxxLP SSSSSss 22
1
020
101
101
2
133
thomas.boerner@dlr.de, slide 4German Aerospace Center Microwaves and Radar Institute
Entropy H and angle
3
1
*
*
3
2
1
3
2
1
321*33
00
00
00
|||
|||
i
Tiii
T
TPP ww
w
w
w
wwwssC
.wherelog3
1
3
13
jj
ii
iii PPPH
3
1iiiP
sinsin
cossin
cos
with33i
iPP
e
ewwss
thomas.boerner@dlr.de, slide 5German Aerospace Center Microwaves and Radar Institute
What does tell us?
= 0 = 90 = 45
thomas.boerner@dlr.de, slide 6German Aerospace Center Microwaves and Radar Institute
H- feasible area
thomas.boerner@dlr.de, slide 7German Aerospace Center Microwaves and Radar Institute
“Classic” Products
Zyy [dBZ] ZDR [dB]
thomas.boerner@dlr.de, slide 8German Aerospace Center Microwaves and Radar Institute
Extracted Products
Entropy H angle [deg]
thomas.boerner@dlr.de, slide 9German Aerospace Center Microwaves and Radar Institute
Populated H- plane
thomas.boerner@dlr.de, slide 10German Aerospace Center Microwaves and Radar Institute
Zyy and Classification
Zyy [dBZ] Classes
thomas.boerner@dlr.de, slide 11German Aerospace Center Microwaves and Radar Institute
15 consecutive PPI Sector Scans
Zyy [dBZ] Classes
thomas.boerner@dlr.de, slide 12German Aerospace Center Microwaves and Radar Institute
Is there a Z-H relation?
thomas.boerner@dlr.de, slide 13German Aerospace Center Microwaves and Radar Institute
Is there a Z- relation?
thomas.boerner@dlr.de, slide 14German Aerospace Center Microwaves and Radar Institute
Conclusions
• It has been shown that it is possible to apply the H- 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.
thomas.boerner@dlr.de, slide 15German Aerospace Center Microwaves and Radar Institute
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 1 or the anisotropy to refine the classification scheme.
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