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| Titel |
Roughness characterizations in active and passive microwave soil moisture retrieval |
| VerfasserIn |
Ying Gao, Jeffrey Walker, Rocco Panciera, Alessandra Monerris, Dongryeol Ryu |
| Konferenz |
EGU General Assembly 2014
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250087768
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| Publikation (Nr.) |
 EGU/EGU2014-1825.pdf |
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| Zusammenfassung |
| Passive microwave remote sensing at L-band is widely recognized as the preferred technique
to measure surface soil moisture globally, with resolution ranging from 40-100km. However,
passive microwave soil moisture retrieval is highly dependent on ancillary data such as
surface roughness, which is difficult to characterize at such a large footprint by ground
measurement. NASA’s Soil Moisture Active Passive (SMAP) mission, scheduled for launch
in Nov 2014, will deploy both active and passive microwave instruments to enhance soil
moisture retrieval capabilities. This provides an opportunity to characterize the
roughness parameter in passive observations with active measurements. However, the
roughness parameters derived from active measurements cannot be directly used in the
passive soil moisture retrieval models. While roughness is usually characterized
by surface Root Mean Square (RMS) height in active microwave, roughness in
passive microwave is described using a parameter HR. This paper compares the two
roughness parameters, retrieved from active and passive scattering and emission models
respectively, using data sets from the third Soil Moisture Active Passive Experiment
(SMAPEx-3) conducted in south-eastern Australia in 2011. Analysis was done
over a series of grassland surfaces located within the experiment focus areas. The
retrieved surface RMS heights from active measurements were validated against
ground samples, after which the relationship between HR and RMS was examined. |
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