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| Titel |
Using vegetation indices for soil-moisture retrievals from passive microwave radiometry |
| VerfasserIn |
E. J. Burke, W. J. Shuttleworth, A. N. French |
| 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 ; 5, no. 4 ; Nr. 5, no. 4, S.671-678 |
| Datensatznummer |
250002716
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| Publikation (Nr.) |
 copernicus.org/hess-5-671-2001.pdf |
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| Zusammenfassung |
| Surface soil moisture
and the nature of the overlying vegetation both influence microwave emission
from land surfaces significantly. One widely discussed but
underused method for allowing for the effect of vegetation on soil-moisture
retrievals from microwave observations is to use remotely
sensed vegetation indices. This paper explores the potential for using the
Normalised Difference Vegetation Index (NDVI) in soil-moisture
retrievals from L-band (1.4 GHz) aircraft data gathered during the Southern
Great Plains '97 (SGP97) experiment. A simplified version
of MICRO-SWEAT, a soil vegetation atmosphere transfer (SVAT) scheme coupled with
a microwave emission model, was used as the retrieval
algorithm. Estimates of the optical depth of the vegetation, the parameter that
describes the effect of the vegetation on microwave emission,
were obtained by calibrating this retrieval algorithm against measurements of
soil moisture at 15 field sites. A significant relationship was
found between the optical depth so obtained and the observed NDVI at these
sites, although this relationship changed with the resolution of
the microwave brightness temperature observations used. Soil-moisture estimates
made with the retrieval algorithm using the empirical relationship
between optical depth and NDVI applied at two additional sites not used in the
calibration show good agreement with field measurements.
Keywords: NDVI, soil moisture, passive microwave, SGP97 |
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