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| Titel |
Developing an improved soil moisture dataset by blending passive and active microwave satellite-based retrievals |
| VerfasserIn |
Y. Y. Liu, R. M. Parinussa, W. A. Dorigo, R. A. M. Jeu, W. Wagner, A. I. J. M. Dijk, M. F. McCabe, J. P. Evans |
| 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. 2 ; Nr. 15, no. 2 (2011-02-01), S.425-436 |
| Datensatznummer |
250012636
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| Publikation (Nr.) |
 copernicus.org/hess-15-425-2011.pdf |
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| Zusammenfassung |
| Combining information derived from satellite-based passive and active
microwave sensors has the potential to offer improved estimates of surface
soil moisture at global scale. We develop and evaluate a methodology that
takes advantage of the retrieval characteristics of passive (AMSR-E) and
active (ASCAT) microwave satellite estimates to produce an improved soil
moisture product. First, volumetric soil water content (m3 m−3)
from AMSR-E and degree of saturation (%) from ASCAT are rescaled against
a reference land surface model data set using a cumulative distribution
function matching approach. While this imposes any bias of the reference on
the rescaled satellite products, it adjusts them to the same range and
preserves the dynamics of original satellite-based products. Comparison with
in situ measurements demonstrates that where the correlation coefficient
between rescaled AMSR-E and ASCAT is greater than 0.65 ("transitional
regions"), merging the different satellite products increases the number of
observations while minimally changing the accuracy of soil moisture
retrievals. These transitional regions also delineate the boundary between
sparsely and moderately vegetated regions where rescaled AMSR-E and ASCAT,
respectively, are used for the merged product. Therefore the merged product
carries the advantages of better spatial coverage overall and increased
number of observations, particularly for the transitional regions. The
combination method developed has the potential to be applied to existing
microwave satellites as well as to new missions. Accordingly, a long-term
global soil moisture dataset can be developed and extended, enhancing basic
understanding of the role of soil moisture in the water, energy and carbon
cycles. |
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