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Titel |
Dual-polarization C-band weather radar algorithms for rain rate estimation and hydrometeor classification in an alpine region |
VerfasserIn |
H. Paulitsch, F. Teschl, W. L. Randeu |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1680-7340
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Digitales Dokument |
URL |
Erschienen |
In: Observation, Prediction and Verification of Precipitation (EGU Session 2008) ; Nr. 20 (2009-03-09), S.3-8 |
Datensatznummer |
250014327
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Publikation (Nr.) |
copernicus.org/adgeo-20-3-2009.pdf |
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Zusammenfassung |
Dual polarization is becoming the standard for new weather radar systems. In
contrast to conventional weather radars, where the reflectivity is measured
in one polarization plane only, a dual polarization radar provides
transmission in either horizontal, vertical, or both polarizations while
receiving both the horizontal and vertical channels simultaneously. Since
hydrometeors are often far from being spherical, the backscatter and
propagation are different for horizontal and vertical polarization.
Comparing the reflected horizontal and vertical power returns and their
ratio and correlation, information on size, shape, and material density of
cloud and precipitation particles can be obtained. The use of polarimetric
radar variables can therefore increase the accuracy of the rain rate
estimation compared to standard Z-R relationships of non-polarimetric
radars. It is also possible to derive the type of precipitation from dual
polarization parameters, although this is not an easy task, since there is
no clear discrimination between the different values. Fuzzy logic approaches
have been shown to work well with overlapping conditions and imprecisely
defined class output.
In this paper the implementation of different polarization algorithms for
the new Austrian weather radar on Mt. Valluga is described, and first
results from operational use are presented. This study also presents first
observations of rain events in August 2007 during the test run of the radar.
Further, the designated rain rate estimation and hydrometeor classification
algorithms are explained. |
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