植被冠层水平叶绿素含量的高光谱估测  

Estimation of Canopy Chlorophyll Content Using Hyperspectral Data

作　　者：董晶晶[1,2] 王力[1] 牛铮[1] 

机构地区：[1]中国科学院遥感应用研究所遥感科学国家重点实验室,北京100101 [2]中国科学院研究生院,北京100049

出　　处：《光谱学与光谱分析》2009年第11期3003-3006,共4页Spectroscopy and Spectral Analysis

基　　金：国家重点基础研究发展规划项目(2007CB714406);中国科学院知识创新工程重要方向项目(KZCX2-YW-313);遥感科学国家重点实验室科研基金项目(KQ060006);国家高技术研究发展专项经费项目(2006AA120108)资助

摘　　要：植物的叶绿素含量指示了其健康状况。大区域范围内植被叶绿素含量信息的提取可以用于评价植被的生长状况,实现对生态环境的监测。对于农田系统而言,作物叶绿素含量的估测还可以对施肥等田间操作提供支持。文章利用辐射传输模型模拟多组不同状态下的植被冠层光谱反射率,通过对模拟数据的冠层叶绿素含量以及冠层光谱之间关系的分析,构建了估测植被冠层水平叶绿素含量的光谱指数模型。该模型对冠层叶绿素含量的方差解释量达到了75%以上。分别使用野外实测冠层光谱和Hyperion高光谱遥感影像对试验区进行验证。结果证明该模型对冠层水平的叶绿素含量估测效果较好,具有应用价值。Many researches have developed models to estimate chlorophyl content at leaf and canopy level,but they were species-specific. The objective of the present paper was to develop a new model. First,canopy reflectance was simulated for different species and different canopy architecture using radiative transfer models. Based on the simulated canopy reflectance,the relationship between canopy reflectance and canopy chlorophyll content was studied,and then a chlorophyll estimation model was built using the method of spectral index. The coefficient of determination （R2） between spectral index based model and canopy chlorophyll content reached 0.75 for simulated data. To investigate the applicability of this chlorophyll model,the authors chose a field sample area in Gansu Province to carry out the measurement of leaf chlorophyll content,canopy reflectance and other parameters. Besides,the authors also ordered the synchronous Hyperion data,a hyperspectral image with a spatial resolution of 30 m. Canopy reflectance from field measurment and reflectance from Hyperion image were respectively used as the input parameter for the chlorophyll estimation model. Both of them got good results,which indicated that the model could be used for accurate canopy chlorophyll estimation using canopy reflectance. However,while using spaceborne hyperspectral data to estimate canopy chlorophyll content,good atmospheric correction is required.

关 键 词：冠层叶绿素含量 光谱指数 辐射传输模型 

分 类 号：P283[天文地球—地图制图学与地理信息工程] TP79[天文地球—测绘科学与技术]