扫描成像光谱仪和地物光谱仪在单叶尺度上的对比研究

【目的】对图谱合一的冬小麦叶片高光谱数据进行分析,验证扫描成像光谱仪(PIS)在近地使用的可行性。【方法】利用扫描成像光谱仪和地物光谱仪(ASD)获取冬小麦关键生育期的叶片光谱信息,比较两仪器在450—850nm获得的光谱曲线;选取15种植被指数,对两仪器获得的光谱值进行植被指数运算,并将结果与叶片叶绿素含量进行相关分析。【结果】在冬小麦的不同生育期,扫描成像光谱仪和地物光谱仪获得叶片的反射率曲线趋势一致,在对应的波段均表现出相应的波峰、波谷、高反射区等特征,但扫描成像光谱仪获得的反射率值都高于地物光谱仪。对比两仪器15种植被指数和叶绿素含量之间的相关系数得出,扫描成像光谱仪获得的相关系数普遍高于地物光谱仪。【结论】扫描成像光谱仪和地物光谱仪获取的数据有相同的曲线特征,说明扫描成像光谱仪获得的数据是可靠的;植被指数与叶绿素含量的相关系数比较结果表明,扫描成像光谱仪获得的图谱合一的数据在近地遥感研究中有很大的优势。

Assessment of the Developed Pushbroom Imaging Spectrometer in Single Leaf Scale

【Objective】 The objective of this study was to verify the feasibility of pushbroom imaging spectrometer（PIS）in the field. 【Method】 Spectral information of wheat leaves in the key growth periods was collected by PIS and ASD Fieldspec-FR2500 (ASD); Meanwhile, the chlorophyll contents of wheat leaves were tested in the lab. A total 15 vegetation indices were calculated by using two instruments’ data which were spectral values from 450 nm to 850 nm. Then correlation coefficients between the same vegetation indices and chlorophyll contents for two applications were analyzed and compared. 【Result】 The results showed that there were same spectrum curve trends of leaf reflectance between PIS and ASD, including the same reflectance peak, valley and high reflectance platform. However, the PIS reflectance data were higher than the ASD data in whole range. Compared with ASD spectrum parameters, PIS got higher correlation coefficients between 15 vegetation indices and chlorophyll contents. 【Conclusion】 It is concluded that PIS spectral data are reliable, and PIS has an important application potential in the near ground remote sensing for it’s advantage of combination image with spectrum.