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The effect of row structure on soil moisture retrieval accuracy from passive microwave data.

Xingming Z, Kai Z, Yangyang L, Jianhua R, Yanling D - ScientificWorldJournal (2014)

Bottom Line: Based on the observed C-band TB, field soil and vegetation parameters, row structure rough surface assumption (Q p model and discrete model), including the effect of row structure, and flat rough surface assumption (Q p model), ignoring the effect of row structure, are used to model microwave TB of soil surface.The results show that soil moisture retrieval accuracy based on the row structure rough surface assumption is approximately 0.02 cm(3)/cm(3) better than the flat rough surface assumption for vegetated soil, as well as 0.015 cm(3)/cm(3) better for bare and wet soil.This result indicates that the effect of row structure cannot be ignored for accurately retrieving soil moisture of farmland surface when C-band is used.

View Article: PubMed Central - PubMed

Affiliation: Northeast Institute of Geographical and Agroecology, Chinese Academy of Sciences, Changchun 130102, China ; Changchun Jingyuetan Remote Sensing Test Site, Chinese Academy of Sciences, Changchun 130102, China.

ABSTRACT
Row structure causes the anisotropy of microwave brightness temperature (TB) of soil surface, and it also can affect soil moisture retrieval accuracy when its influence is ignored in the inversion model. To study the effect of typical row structure on the retrieved soil moisture and evaluate if there is a need to introduce this effect into the inversion model, two ground-based experiments were carried out in 2011. Based on the observed C-band TB, field soil and vegetation parameters, row structure rough surface assumption (Q p model and discrete model), including the effect of row structure, and flat rough surface assumption (Q p model), ignoring the effect of row structure, are used to model microwave TB of soil surface. Then, soil moisture can be retrieved, respectively, by minimizing the difference of the measured and modeled TB. The results show that soil moisture retrieval accuracy based on the row structure rough surface assumption is approximately 0.02 cm(3)/cm(3) better than the flat rough surface assumption for vegetated soil, as well as 0.015 cm(3)/cm(3) better for bare and wet soil. This result indicates that the effect of row structure cannot be ignored for accurately retrieving soil moisture of farmland surface when C-band is used.

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Related in: MedlinePlus

The change in s/cl (a) and VWC (b) with the sampling date. s/cl (the ratio of root mean square height and correlation length) denotes surface roughness parameter and VWC denotes vegetation water content.
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Related In: Results  -  Collection


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fig5: The change in s/cl (a) and VWC (b) with the sampling date. s/cl (the ratio of root mean square height and correlation length) denotes surface roughness parameter and VWC denotes vegetation water content.

Mentions: Figure 5(a) shows the change of surface roughness with the sampling date in vegetated soil. The ratio of surface root mean square height and correlation length (s/cl) increases first and then decreases with the change of the sampling date. The maximum of s/cl appears at the day of 203 because soil surface is tilled. Then, due to the influence of rain, wind, and gravity, the surface roughness decreases until it becomes constant.


The effect of row structure on soil moisture retrieval accuracy from passive microwave data.

Xingming Z, Kai Z, Yangyang L, Jianhua R, Yanling D - ScientificWorldJournal (2014)

The change in s/cl (a) and VWC (b) with the sampling date. s/cl (the ratio of root mean square height and correlation length) denotes surface roughness parameter and VWC denotes vegetation water content.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4216705&req=5

fig5: The change in s/cl (a) and VWC (b) with the sampling date. s/cl (the ratio of root mean square height and correlation length) denotes surface roughness parameter and VWC denotes vegetation water content.
Mentions: Figure 5(a) shows the change of surface roughness with the sampling date in vegetated soil. The ratio of surface root mean square height and correlation length (s/cl) increases first and then decreases with the change of the sampling date. The maximum of s/cl appears at the day of 203 because soil surface is tilled. Then, due to the influence of rain, wind, and gravity, the surface roughness decreases until it becomes constant.

Bottom Line: Based on the observed C-band TB, field soil and vegetation parameters, row structure rough surface assumption (Q p model and discrete model), including the effect of row structure, and flat rough surface assumption (Q p model), ignoring the effect of row structure, are used to model microwave TB of soil surface.The results show that soil moisture retrieval accuracy based on the row structure rough surface assumption is approximately 0.02 cm(3)/cm(3) better than the flat rough surface assumption for vegetated soil, as well as 0.015 cm(3)/cm(3) better for bare and wet soil.This result indicates that the effect of row structure cannot be ignored for accurately retrieving soil moisture of farmland surface when C-band is used.

View Article: PubMed Central - PubMed

Affiliation: Northeast Institute of Geographical and Agroecology, Chinese Academy of Sciences, Changchun 130102, China ; Changchun Jingyuetan Remote Sensing Test Site, Chinese Academy of Sciences, Changchun 130102, China.

ABSTRACT
Row structure causes the anisotropy of microwave brightness temperature (TB) of soil surface, and it also can affect soil moisture retrieval accuracy when its influence is ignored in the inversion model. To study the effect of typical row structure on the retrieved soil moisture and evaluate if there is a need to introduce this effect into the inversion model, two ground-based experiments were carried out in 2011. Based on the observed C-band TB, field soil and vegetation parameters, row structure rough surface assumption (Q p model and discrete model), including the effect of row structure, and flat rough surface assumption (Q p model), ignoring the effect of row structure, are used to model microwave TB of soil surface. Then, soil moisture can be retrieved, respectively, by minimizing the difference of the measured and modeled TB. The results show that soil moisture retrieval accuracy based on the row structure rough surface assumption is approximately 0.02 cm(3)/cm(3) better than the flat rough surface assumption for vegetated soil, as well as 0.015 cm(3)/cm(3) better for bare and wet soil. This result indicates that the effect of row structure cannot be ignored for accurately retrieving soil moisture of farmland surface when C-band is used.

Show MeSH
Related in: MedlinePlus