Sun Lin, Cheng Li-juan
Geomatics College, Shandong University of Science and Technology, Qingdao 266510, China.
Guang Pu Xue Yu Guang Pu Fen Xi. 2010 Nov;30(11):3031-5.
Based on the leaf spectra data measured with LOPEX'93, the authors analyzed the relationship between leaf spectra and leaf biochemical components including leaf chlorophyll and leaf water content. It was showed that leaf chlorophyll was highly correlated with the second derivation of leaf reflectance at wavelengths 700, 670, 600, 500, 490, 440, and 410 nm; similarly, it was also showed that leaf water content was highly correlated with the continuum removed leaf reflectance at wavelengths 2350, 2180, 2130, 2120, 1870, and 1820 nm, which correspond to the absorption features of water in shortwave infrared bands. In addition, the authors found that ND (Normalized Difference) has a higher response to chlorophyll than other spectral indexes and the correlation coefficient is 0.618; Ratio975 has a very high response to water content and the correlation coefficient is up to 0.996. Based on the above evidences, the authors built a model to retrieve leaf chlorophyll and leaf water content through ground measured leaf spectra data and the simulated leaf chlorophyll and leaf water content are very accurate as compared to the ground measurements.
基于用LOPEX'93测量的叶片光谱数据,作者分析了叶片光谱与包括叶片叶绿素和叶片含水量在内的叶片生化成分之间的关系。结果表明,叶片叶绿素与700、670、600、500、490、440和410 nm波长处叶片反射率的二阶导数高度相关;同样,也表明叶片含水量与2350、2180、2130、2120、1870和1820 nm波长处的连续统去除叶片反射率高度相关,这些波长对应于短波红外波段水的吸收特征。此外,作者发现归一化差异(ND)对叶绿素的响应比其他光谱指数更高,相关系数为0.618;Ratio975对含水量的响应非常高,相关系数高达0.996。基于上述证据,作者建立了一个通过地面测量的叶片光谱数据反演叶片叶绿素和叶片含水量的模型,与地面测量相比,模拟的叶片叶绿素和叶片含水量非常准确。