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| Titel |
Monitoring vegetation dynamics in the Amazon with RapidScat |
| VerfasserIn |
Tim van Emmerik, Susan Steele-Dunne, Aaron C. Paget, Nick van de Giesen |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250141819
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| Publikation (Nr.) |
 EGU/EGU2017-5364.pdf |
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| Zusammenfassung |
| Several studies affiliated diurnal variations in radar backscatter over the Amazon [1,2] with
vegetation water stress. Recent studies on tree and corn canopies [3,4] have demonstrated that
during periods of low soil moisture availability, the total radar backscatter is primarily
sensitive to changes in leaf water content, highlighting the potential of radar for water stress
detection.
The RapidScat mission (Ku-band, 13.4GHz), mounted on the International Space Station,
observes the Earth in a non-sun-synchronous orbit [5]. This unique orbit allows for
reconstructing diurnal cycles of radar backscatter. We hypothesize that the state of
the canopy is a significant portion of the diurnal variations observed in the radar
backscatter. Recent, yet inconclusive, analyses support the theory of the impact of
vegetation water content on diurnal variation in RapidScat radar backscatter over the
Amazon and Congo. Linking ground measurements of canopy dynamics to radar
backscatter will allow further exploration of the possibilities for monitoring vegetation
dynamics.
Our presentation focuses of two parts. First, we reconstruct diurnal cycles of
RapidScat backscatter over the Amazon, and study its variation over time. Second, we
analyze the pre-dawn backscatter over time. The water content at this time of day is
a measure of water stress, and might therefore be visible in the backscatter time
series.
References
[1] Frolking, S., et al.: "Tropical forest backscatter anomaly evident in SeaWinds scatterometer morning overpass
data during 2005 drought in Amazonia", Remote Sensing of Environment, 2011.
[2] Jaruwatanadilok, S., and B. Stiles: "Trends and variation in Ku-band backscatter of natural
targets on land observed in QuikSCAT data", IEEE Transactions on Geoscience and Remote Sensing ,
2014.
[3] Steele-Dunne, S., et al.: "Using diurnal variation in backscatter to detect vegetation water stress", IEEE
Transactions on Geoscience and Remote Sensing, 2012.
[4] van Emmerik, T., et al.: "Impact of diurnal variation in vegetation water content on radar backscatter from
maize during water stress", IEEE Transactions on Geoscience and Remote Sensing, 2015.
[5] Paget, A., et al.: "RapidScat Diurnal Cycles Over Land", IEEE Transactions on Geoscience and Remote
Sensing, 2016. |
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