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Titel |
Downscaling of METEOSAT SEVIRI 0.6 and 0.8 μm channel radiances utilizing the high-resolution visible channel |
VerfasserIn |
H. M. Deneke, R. A. Roebeling |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1680-7316
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Digitales Dokument |
URL |
Erschienen |
In: Atmospheric Chemistry and Physics ; 10, no. 20 ; Nr. 10, no. 20 (2010-10-18), S.9761-9772 |
Datensatznummer |
250008832
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Publikation (Nr.) |
copernicus.org/acp-10-9761-2010.pdf |
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Zusammenfassung |
An algorithm is introduced to downscale the 0.6 and 0.8 μm
spectral channels of the METEOSTAT SEVIRI satellite imager from
3×3 km2 (LRES) to 1×1 km2 (HRES) resolution
utilizing SEVIRI's high-resolution visible channel
(HRV). Intermediate steps include the coregistration of low- and
high-resolution images, lowpass filtering of the HRV channel with
the spatial response function of the narrowband channels, and the
estimation of a least-squares linear regression model for linking
high-frequency variations in the HRV and narrowband images. The
importance of accounting for the sensor spatial response function for
matching reflectances at different spatial resolutions is
demonstrated, and an estimate of the accuracy of the downscaled
reflectances is provided. Based on a 1-year dataset of Meteosat SEVIRI
images, it is estimated that on average, the reflectance of a HRES
pixel differs from that of an enclosing LRES pixel by standard
deviations of 0.049 and 0.052 in the 0.6 and 0.8 μm channels,
respectively. By applying our downscaling algorithm, explained
variance of 98.2 and 95.3 percent are achieved for estimating these
deviations, corresponding to residual standard deviations of only
0.007 and 0.011 for the respective channels. For this dataset,
a minor misregistration of the HRV channel relative to the
narrowband channels of 0.36±0.11 km in East and 0.06±0.10 km
in South direction is observed and corrected for, which should be
negligible for most applications. |
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