基于无人机成像光谱仪数据的棉花叶绿素含量反演  

Estimation of SPAD Value of Cotton Leaf Using Hyperspectral Images from UAV-based Imaging Spectroradiometer

作　　者：田明璐[1] 班松涛[1] 常庆瑞[1] 马文君[1] 殷紫[1] 王力[1] 

机构地区：[1]西北农林科技大学资源环境学院,陕西杨凌712100

出　　处：《农业机械学报》2016年第11期285-293,共9页Transactions of the Chinese Society for Agricultural Machinery

基　　金：国家高技术研究发展计划(863计划)项目(2013AA102401-2)

摘　　要：以棉花为目标作物,使用低空无人机平台的成像光谱仪获取地表农作物高光谱影像,利用无人机影像光谱分辨率高的特点,提取27个光谱参数,构建棉花叶片叶绿素相对含量(SPAD)的反演模型,并制作棉花叶片SPAD分布图。结果表明:在影像上,不同叶片SPAD的棉花冠层反射率有显著差异。光谱参数中,与SPAD相关性最高的为DR526、DR578、SDy和Db,相关系数绝对值都在0.8以上。在各光谱参数参与建立的SPAD反演模型中,使用多元逐步回归和偏最小二乘回归方法的模型精度最高。对高光谱影像结合各模型制作的SPAD分布图进行精度分析,结果表明,使用SPAD-PLSR模型得到的分布图具有最佳预测效果,可以作为棉花叶片SPAD遥感监测的技术手段。The development of modern technology has made hyperspectral sensors much smaller in size and lighter in weight, which can be carried by unmanned aerial vehicles （UAVs）. A new type of imaging spectroradiometer based on UAV was used to acquire the hyperspeetal images of cotton field, which were used to establish the regression model aiming to predict the SPAD value of cotton leaf and make its distribution map. The results showed that in the wavelength range of 720 ~ 850 nm, the reflectance had positive correlation with SPAD value. Many spectral indexes based on the hyperspectal images were significantly correlated to the SPAD value of cotton leaf on P 〈 0.01 level. The absolute correlation coefficients of four indexes, including DR52~, DR57s, So, and Ob were all above O. 8. DRsz6, DRsTs, So, and Db were used to establish the simple regression model of SPAD respectively. All the spectral indexes whose absolute correlation coefficients with SPAD value were above O. 7 were chosen to establish the multiple regression inversion model of SPAD using multiple stepwise regression （MSR） method and partial least squares regression（PLSR） method. According to the accuracy test, both SPAD- MSR model and SPAD - PLSR model had high accuracy to predict the SPAD value of cotton leaf. The six inversion models of SPAD were used to make the distribution map of cotton leaf SPAD value. The map using SPAD - PLSR model had the best result which was the closest to real SPAD distribution. Thus this research provides a new technology to supervise the growth information of cotton and other crops.

关 键 词：棉花 叶绿素相对含量 低空无人机 成像光谱仪 遥感 反演 

分 类 号：TP79[自动化与计算机技术—检测技术与自动化装置] S127[自动化与计算机技术—控制科学与工程]