• Spectroscopy and Spectral Analysis
  • Vol. 33, Issue 9, 2546 (2013)
ZHAO Juan1、2、*, HUANG Wen-jiang1, ZHANG Yao-hong1, and JING Yuan-shu2
Author Affiliations
  • 1[in Chinese]
  • 2[in Chinese]
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    DOI: 10.3964/j.issn.1000-0593(2013)09-2546-07 Cite this Article
    ZHAO Juan, HUANG Wen-jiang, ZHANG Yao-hong, JING Yuan-shu. Inversion of Leaf Area Index during Different Growth Stages in Winter Wheat[J]. Spectroscopy and Spectral Analysis, 2013, 33(9): 2546 Copy Citation Text show less

    Abstract

    Being orientated to the low prescion of crop leaf area index (LAI) inversion using the same spectral vegetation index during different crop growth stages, the present paper analyzed the precision of LAI inversion by employing NDVI(normalized difference vegetation index). Ten vegetation indices were chosen including six broad-band vegetation indices and four narrow-band vegetation indices responding to vegetation cover to inverse LAI in different growth stages. Several conclusions were drawn according to the analysis. The determinant coefficient (R2) and root mean square error(RMSE) between LAI inversion value and true value were 0.558 5 and 0.320 9 respectively during the whole growth duraton. The mSR(modified simple ratio index) index was appropriate to inverse of LAI during earlier growth stages (before jointing stage) in winter wheat. The R2 and RMSE between LAI inversion value and true value were 0.728 7 and 0.297 1 respectively. The SR(simple ratio index) index was suitable enough to inverse of LAI during medium growth stages (from joingting stagess to heading stagess). The R2 and RMSE between LAI inversion value and true value were 0.654 6 and 0.306 1 respectively. The NDVI(normalized difference vegetation index) index was proven to be fine to inverse LAI during later growth stages(from heading stage to ripening stage). The R2 and RMSE between LAI inversion value and true value were 0.679 4 and 0.316 4 respectively. Therefore it was indicated that the results of LAI inversion was much better inverse of winter wheat LAI choosing different vegetation indices during differen growth stages for winter wheat according to the change of vegetation cover and canopy reflectance than merely with NDVI to inverse LAI in the whole growth stages. It was concluded that the precision of LAI inversion was significantly improved with segmented models based on different vegetation indices.
    ZHAO Juan, HUANG Wen-jiang, ZHANG Yao-hong, JING Yuan-shu. Inversion of Leaf Area Index during Different Growth Stages in Winter Wheat[J]. Spectroscopy and Spectral Analysis, 2013, 33(9): 2546
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