Soil isoline equations in the red-NIR reflectance subspace describe a heterogeneous canopy
Soil isoline equations in the red-NIR reflectance subspace describe a heterogeneous canopy
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红近红外反射子空间中的土壤等值线方程描述了异质冠层
DOI：
10.1117/1.jrs.10.016013
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发表时间：
2016
影响因子：
1.7
通讯作者：
Kenta Obata and Hiroki Yoshioka
中科院分区：
文献类型：
--
作者：
Kenta Taniguchi;Kenta Obata and Hiroki Yoshioka
本研究介绍了部分冠层覆盖情况下土壤等值线方程的推导。该推导依赖于扩展先前推导的土壤等值线方程，该方程假设完全的冠层覆盖。这一扩展是通过采用双波段线性混合模型实现的，其中植被覆盖率（FVC）被明确视为生物物理参数。由此推导出考虑 FVC 影响的土壤等值线方程的参数形式。分析探讨了完全覆盖和部分覆盖情况下土壤等值线之间的差异。本研究导出了通过选择参数形式的截断阶数定义的九种情况的近似等值线方程。使用耦合的叶子和冠层辐射传输模型进行了一组数值实验。数值结果表明，土壤等值线的精度随着截断阶次的增加而增加，并证实了推导表达式的有效性。
This study introduces derivations of the soil isoline equation for the case of partial canopy coverage. The derivation relied on extending the previously derived soil isoline equations, which assumed full canopy coverage. This extension was achieved by employing a two-band linear mixture model, in which the fraction of vegetation cover (FVC) was considered explicitly as a biophysical parameter. A parametric form of the soil isoline equation, which accounted for the influence of the FVC, was thereby derived. The differences between the soil isolines of the fully covered and partially covered cases were explored analytically. This study derived the approximated isoline equations for nine cases defined by the choice of the truncation order in the parametric form. A set of numerical experiments was conducted using coupled leaf and canopy radiative transfer models. The numerical results revealed that the accuracy of the soil isoline increased with the truncation order, and they confirmed the validity of the derived expressions.