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| Titel |
Performance of high-resolution X-band weather radar networks – the PATTERN example |
| VerfasserIn |
K. Lengfeld, M. Clemens, H. Münster, F. Ament |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1867-1381
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Measurement Techniques ; 7, no. 12 ; Nr. 7, no. 12 (2014-12-05), S.4151-4166 |
| Datensatznummer |
250115977
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| Publikation (Nr.) |
 copernicus.org/amt-7-4151-2014.pdf |
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| Zusammenfassung |
This publication intends to prove that a network of low-cost local area
weather radars (LAWR) is a reliable and scientifically valuable complement to
nationwide radar networks. A network of four LAWRs has been installed in
northern Germany within the framework of the Precipitation and Attenuation
Estimates from a High-Resolution Weather Radar Network (PATTERN) project
observing precipitation with a temporal resolution of 30 s, a range
resolution of 60 m and a sampling resolution of 1° in the azimuthal
direction. The network covers an area of 60 km × 80 km. In this
paper, algorithms used to obtain undisturbed precipitation fields from raw
reflectivity data are described, and their performance is analysed. In order
to correct operationally for background noise in reflectivity measurements,
noise level estimates from the measured reflectivity field are combined with
noise levels from the last 10 time steps. For detection of non-meteorological
echoes, two different kinds of clutter algorithms are applied: single-radar
algorithms and network-based algorithms. Besides well-established algorithms
based on the texture of the logarithmic reflectivity field (TDBZ) or sign
changes in the reflectivity gradient (SPIN), the advantage of the unique
features of the high temporal and spatial resolution of the network is used
for clutter detection. Overall, the network-based clutter algorithm works
best with a detection rate of up to 70%, followed by the classic TDBZ
filter using the texture of the logarithmic reflectivity field.
A comparison of a reflectivity field from the PATTERN network with the
product from a C-band radar operated by the German Meteorological Service
indicates high spatial accordance of both systems in the geographical
position of the rain event as well as reflectivity maxima. Long-term
statistics from May to September 2013 prove very good accordance of the
X-band radar of the network with C-band radar, but, especially at the border
of precipitation events, higher-resolved X-band radar measurements provide
more detailed information on precipitation structure because the 1 km range
gate of C-band radars is only partially covered with rain. The standard
deviation within a range gate of the C-band radar with a range resolution of
1 km is up to 3 dBZ at the borders of rain events. The probability of
detection is at least 90%, the false alarm ratio less than 10% for
both systems. Therefore, a network of high-resolution low-cost LAWRs can give
valuable information on the small-scale structure of rain events in areas of
special interest, e.g. urban regions, in addition to the nationwide radar
networks. |
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