基于高光谱反射率的棉花冠层叶绿素密度估算
为了进一步提高棉花叶绿素密度高光谱估算精度,该研究以棉花冠层叶绿素密度以及冠层高光谱反射率为数据源,在分析叶绿素密度与原始高光谱反射率(R)、一阶导数光谱反射率(DR)、已有光谱指数及全波段组合指数相关性的基础上,采用线性及多元逐步回归技术构建了叶绿素密度高光谱诊断模型,系统对比分析了以上4种光谱形式用于棉花冠层叶绿素密度诊断的精度。结果表明:1)基于一阶导数光谱反射率的估算模型精度明显优于原始光谱反射率;2)基于比值指数或归一化指数形式的估算模型精度及稳定性要优于单波段或多波段的线性模型;3)单波段变量DR756、全波度组合比值指数DR635/DR643以及归一化指数(DR1055-DR68...
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Published in | 农业工程学报 Vol. 28; no. 15; pp. 125 - 132 |
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Main Author | |
Format | Journal Article |
Language | Chinese |
Published |
中国科学院新疆生态与地理研究所,乌鲁木齐830011%中国科学院研究生院,北京100049
2012
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Subjects | |
Online Access | Get full text |
ISSN | 1002-6819 |
DOI | 10.3969/j.issn.1002-6819.2012.15.020 |
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Summary: | 为了进一步提高棉花叶绿素密度高光谱估算精度,该研究以棉花冠层叶绿素密度以及冠层高光谱反射率为数据源,在分析叶绿素密度与原始高光谱反射率(R)、一阶导数光谱反射率(DR)、已有光谱指数及全波段组合指数相关性的基础上,采用线性及多元逐步回归技术构建了叶绿素密度高光谱诊断模型,系统对比分析了以上4种光谱形式用于棉花冠层叶绿素密度诊断的精度。结果表明:1)基于一阶导数光谱反射率的估算模型精度明显优于原始光谱反射率;2)基于比值指数或归一化指数形式的估算模型精度及稳定性要优于单波段或多波段的线性模型;3)单波段变量DR756、全波度组合比值指数DR635/DR643以及归一化指数(DR1055-DR684)/(DR1055+DR684)均可较好的实现叶绿素密度估算,其中由DR635/DR643为自变量的模型所得到棉花冠层叶绿素密度估算值与实测值拟合最好,相关系数达到0.821。该研究可为高光谱技术在棉花冠层叶绿素密度诊断中的更好应用提供参考。 |
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Bibliography: | Wang Qiangi, Yi Qiuxiang, Bao Anmingi, Luo Yi, Zhao Jin (1. Xinjiang Institute of Ecology and Geography Chinese Academy of Sciences, Xinjiang UR UMQ1830011, China; 2. Graduate University of Chinese Academy of Sciences, Beijing 100049, China) 11-2047/S cotton, chlorophyll, models, hyperspectral reflectance, vegetation index In order to further improve the estimation accuracy of cotton chlorophyll density by hyperspectral reflectance, canopy hyperspectral reflectance and chlorophyll density were recorded at four different growth stages of cotton in a field experiment. All two-band combinations (350 to 1100 nm) in the ratio type of vegetation index (RV1) and the normalized difference type of vegetation index (NDV1) were performed on raw spectral reflectance and the first derivative reflectance, and then the correlation between all two-band combinations and cholorophyll density were determined. The coefficients (r) were presented in matrix plots. Basing on the results of correlation analysis, the estimation models o |
ISSN: | 1002-6819 |
DOI: | 10.3969/j.issn.1002-6819.2012.15.020 |