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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 scatter plot between field and retrieved volumetric soil moisture (vsm). (◯: Qp model, ◊: discrete model and Qp model, and —: 1 : 1 line).
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fig7: The scatter plot between field and retrieved volumetric soil moisture (vsm). (◯: Qp model, ◊: discrete model and Qp model, and —: 1 : 1 line).

Mentions: Based on multiangle (40°, 50°, 55°, 60°, and 70°) C-band brightness temperature in vegetated soil, soil moisture is retrieved based on two different farmland surface assumptions. Compared with field volumetric soil moisture, the rmse of retrieval soil moisture based on row structure rough surface assumption (discrete model and Qp model) is 0.0253 cm3/cm3, and the rmse of retrieval soil moisture for flat rough surface assumption (Qp model) is 0.046 cm3/cm3. The rmse of retrieval soil moisture based on row structure rough surface assumption is 0.021 cm3/cm3 lower than that of flat rough surface assumption. Also found from Figure 7, the retrieval volumetric soil moisture based on row structure surface assumption is closer to 1 : 1 line than the flat surface assumption. This result indicates that row structure surface assumption can improve the accuracy of retrieval soil moisture even if vegetation exists on the soil surface.


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 scatter plot between field and retrieved volumetric soil moisture (vsm). (◯: Qp model, ◊: discrete model and Qp model, and —: 1 : 1 line).
© Copyright Policy - open-access
Related In: Results  -  Collection

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

fig7: The scatter plot between field and retrieved volumetric soil moisture (vsm). (◯: Qp model, ◊: discrete model and Qp model, and —: 1 : 1 line).
Mentions: Based on multiangle (40°, 50°, 55°, 60°, and 70°) C-band brightness temperature in vegetated soil, soil moisture is retrieved based on two different farmland surface assumptions. Compared with field volumetric soil moisture, the rmse of retrieval soil moisture based on row structure rough surface assumption (discrete model and Qp model) is 0.0253 cm3/cm3, and the rmse of retrieval soil moisture for flat rough surface assumption (Qp model) is 0.046 cm3/cm3. The rmse of retrieval soil moisture based on row structure rough surface assumption is 0.021 cm3/cm3 lower than that of flat rough surface assumption. Also found from Figure 7, the retrieval volumetric soil moisture based on row structure surface assumption is closer to 1 : 1 line than the flat surface assumption. This result indicates that row structure surface assumption can improve the accuracy of retrieval soil moisture even if vegetation exists on the soil surface.

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