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Estimating chlorophyll content from hyperspectral vegetation indices: Modeling and validation

文献类型: 外文期刊

作者: Wu, Chaoyang 1 ; Niu, Zheng 1 ; Tang, Quan 1 ; Huang, Wenjiang 3 ;

作者机构: 1.Chinese Acad Sci, Inst Remote Sensing Applicat, State Key Lab Remote Sensing Sci, Beijing 100101, Peoples R China

2.Chinese Acad Sci, Grad Univ, Beijing 100039, Peoples R China

3.Natl Engn Res Ctr Informat Technol Agr, Beijing 100089, Peoples R China

关键词: vegetation indices; sensitivity; chlorophyll content; LAI; validation

期刊名称:AGRICULTURAL AND FOREST METEOROLOGY ( 影响因子:5.734; 五年影响因子:5.964 )

ISSN: 0168-1923

年卷期: 2008 年 148 卷 8-9 期

页码:

收录情况: SCI

摘要: Leaf chlorophyll content, a good indicator of photosynthesis activity, mutations, stress and nutritional state, is of special significance to precision agriculture. Recent studies have demonstrated the feasibility of retrieval of chlorophyll content from hyperspectral vegetation indices composed by the reflectance of specific bands. in this paper, a set of vegetation indices belonged to three classes (normalized difference vegetation index (NDVI), modified simple ratio (MSR) index and the modified chlorophyll absorption ratio index (MCARI, TCARI) and the integrated forms (MCARI/OSAVI and TCARI/OSAVI)) were tested using the PROSPECT and SAIL models to explore their potentials in chlorophyll content estimation. Different bands combinations were also used to derive the modified vegetation indices. In the sensitivity study, four new formed indices (MSR[705,750], MCARI[705,750], TCARI/OSAVI[705,750] and MCARI/ OSAVI[705,750]) were proved to have better linearity with chlorophyll content and resistant to leaf area index (LAI) variations by taking into account the effect of quick saturation at 670 nm with relatively low chlorophyll content. Validation study was also conducted at canopy scale using the ground truth data in the growth duration of winter wheat (chlorophyll content and reflectance data). The results showed that the integrated indices TCARI/OSAVI[705,750] and MCARI/OSAVI[705,750] are most appropriate for chlorophyll estimation with high correlation coefficients R-2 of 0.8808 and 0.9406, respectively, because more disturbances such as shadow, soil reflectance and nonphotosynthetic materials are taken into account. The high correlation between the vegetation indices obtained in the developmental stages of wheat and Hyperion data (R-2 of 0.6798 and 0.7618 for TCARI/OSAVI[705,750] and MCARI/OSAVI[705,750], respectively) indicated that these two integrated index can be used in practice to estimate the chlorophylls of different types of corns. (C) 2008 Elsevier B.V. All rights reserved.

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