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| Titel |
Potential of high-resolution detection and retrieval of precipitation fields from X-band spaceborne synthetic aperture radar over land |
| VerfasserIn |
F. S. Marzano, S. Mori, M. Chini, L. Pulvirenti, N. Pierdicca, M. Montopoli, J. A. Weinman |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1027-5606
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| Digitales Dokument |
URL |
| Erschienen |
In: Hydrology and Earth System Sciences ; 15, no. 3 ; Nr. 15, no. 3 (2011-03-11), S.859-875 |
| Datensatznummer |
250012686
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| Publikation (Nr.) |
 copernicus.org/hess-15-859-2011.pdf |
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| Zusammenfassung |
| X-band Synthetic Aperture Radars (X-SARs), able to image the Earth's surface
at metric resolution, may provide a unique opportunity to measure rainfall
over land with spatial resolution of about few hundred meters, due to the
atmospheric moving-target degradation effects. This capability has become
very appealing due to the recent launch of several X-SAR satellites, even
though several remote sensing issues are still open. This work is devoted
to: (i) explore the potential of X-band high-resolution detection and
retrieval of rainfall fields from space using X-SAR signal backscattering
amplitude and interferometric phase; (ii) evaluate the effects of spatial
resolution degradation by precipitation and inhomogeneous beam filling when
comparing to other satellite-based sensors. Our X-SAR analysis of
precipitation effects has been carried out using both a TerraSAR-X (TSX)
case study of Hurricane "Gustav" in 2008 over Mississippi (USA) and a
COSMO-SkyMed (CSK) X-SAR case study of orographic rainfall over Central
Italy in 2009. For the TSX case study the near-surface rain rate has been
retrieved from the normalized radar cross section by means of a modified
regression empirical algorithm (MREA). A relatively simple method to account
for the geometric effect of X-SAR observation on estimated rainfall rate and
first-order volumetric effects has been developed and applied. The
TSX-retrieved rain fields have been compared to those estimated from the
Next Generation Weather Radar (NEXRAD) in Mobile (AL, USA). The rainfall
detection capability of X-SAR has been tested on the CSK case study using
the repeat-pass coherence response and qualitatively comparing its signature
with ground-based Mt. Midia C-band radar in central Italy. A numerical
simulator to represent the effect of the spatial resolution and the antenna
pattern of TRMM satellite Precipitation Radar (PR) and Microwave Imager
(TMI), using high-resolution TSX-retrieved rain images, has been also set up
in order to evaluate the rainfall beam filling phenomenon. As expected, the
spatial average can modify the statistics of the high-resolution
precipitation fields, strongly reducing its dynamics in a way non-linearly
dependent on the rain rate local average value. |
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