基于DART模型的PROBA/CHRIS数据叶面积指数反演
DART Model-Based Inversion of Leaf Area Index from PROBA/CHRIS Data
王明常 1牛雪峰 2陈圣波 2王亚楠 3汪自军4
作者信息
- 1. 吉林大学地球探测科学与技术学院,长春 130026;千叶工业大学建筑与城市环境学院,日本 千叶 275-0016
- 2. 吉林大学地球探测科学与技术学院,长春 130026
- 3. 长春市测绘院,长春 130021
- 4. 上海工程卫星研究所,上海 200240
- 折叠
摘要
叶面积指数(LAI)是生态环境研究中一个关键的生物物理变量,是陆地植被能量交换的重要途径.基于多角度高光谱植被辐射传输理论,根据DART模型,将天项角和方位角离散成61个方向组合,建立适于多角度高光谱遥感数据的叶面积指数反演查找表；选取长白山地区高光谱多角度PROBA/CHRIS遥感数据,在进行CHRIS数据预处理的基础上,利用最小二乘原理进行CHRIS数据与LAI查找表匹配,反演研究区的LAI;并对490 nm和700 nm波长在不同LAI和61个离散方向的BRDF敏感性因子进行评价分析:随着LAI值的增大,490 nm波长的BRDF值先增大后减小,700 nm波长的BRDF值减小；BRDF值沿天顶角增大的方向下降,在天顶附近时值为最小.
Abstract
Leaf Area Index(LAI) is a key structural and functional biophysical variable in the study of ecological environment research,also,an important path of energy exchange of terrestrial vegetation.Through the study on radiative transfer theory of vegetation from multi-angular,hyper-spectral data,LAI is estimated by bidirectional reflectance distribution function (BRDF).According to discrete anisotropic radiative transfer(DART) model,the zenith angle and azimuth are discretized to 61 direction combinations,look-up-table(LUT) of LAI inversion which is suitable for multi-angular and hyperspectral data is constructed.Then,PROBA/CHRIS data in Changbai Mountain area is selected,pre-processed,and matched with LUT based on least squares principle,LAI in the research area is retrieved.Subsequently,the sensitive factors of LAI to BRDF,of 470 nm and 700 nm bands,in the 61 discrete directions,are evaluated.With LAI values increasing,BRDF value of 490 nm wavelength increases firstly and decreases successively,and BRDF value of 700 nm wavelength decreases; BRDF value decreases when zenith angle increases,and reaches minimum near the zenith.
关键词
遥感/高光谱图像/DART模型/叶面积指数/CHRIS数据/查找表Key words
remote sensing/hyperspectral imagery/DART model/leaf area index, CHRIS data/look-up-table引用本文复制引用
基金项目
国家自然科学基金(40971187)
中央高校基本科研业务费专项项目(200903046)
出版年
2013
NETL
NSTL
维普
万方数据