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	Validation methods of LAI products on the basis of scaling effect
	Liao Yanran; Gai Yingying; Yao Yanjuan; Fan Wenjie; Xu Xiru; Yan Binyan
来源期刊	Journal of Remote Sensing
ISSN	1007-4619
出版年	2015
卷号	19 期号:1 页码:134-142
英文摘要	Validation is one of the most important processes used to evaluate whether remotely sensed products can accurately reflect land surface configuration. Leaf Area Index (LAI) is a key parameter that represents vegetation canopy structures and growth conditions. Accurate evaluation of LAI products is the basis for applying them to land surface models. In this study, validation methods of coarse resolution MODIS and GLASS LAI products for heterogeneous pixels are established on the basis of the scaling effect and the scaling transformation. Considering spatial heterogeneity and growth difference, we transformed LAI from field measurements into a 1 km resolution scale with the aid of middle resolution images. We used average LAI and apparent LAI separately to validate the algorithms and products of MODIS and GLASS LAI. Two study areas,Hebi City and the Yingke Oasis, were selected for validation. Both MODIS and GLASS LAI products underestimate the true LAI in crop area. However, this result cannot be completely attributed to their algorithms. Instead,the primary reason is the heterogeneity and nonuniformity of the coarse pixels. Underestimation is evident in the Yingke Oasis, where heterogeneity is significant. Given that GLASS LAI product is the fusion of multiple LAI products,the mean value of this product is closer to the real situation,but the dynamic range is narrower than that of MODIS LAI product.
英文关键词	validation leaf area index scaling effect scaling transformation
类型	Article
语种	英语
收录类别	CSCD
WOS研究方向	Remote Sensing
CSCD记录号	CSCD:5331353
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/335432
作者单位	Liao Yanran, Institute of Remote Sensing and GIS, Peking University, Beijing Key Laboratory of Spatial Information Integration & Its Applications, Beijing 100871, China.; Fan Wenjie, Institute of Remote Sensing and GIS, Peking University, Beijing Key Laboratory of Spatial Information Integration & Its Applications, Beijing 100871, China.; Xu Xiru, Institute of Remote Sensing and GIS, Peking University, Beijing Key Laboratory of Spatial Information Integration & Its Applications, Beijing 100871, China.; Gai Yingying, Institute of Oceanographic Instrumentation, Shandong Academy of Sciences, Qingdao, Shandong 266001, China.; Yao Yanjuan, Satellite Environment Center, Ministry of Environmental Protection, Beijing 100094, China.; Yan Binyan, Jackson School of Geosciences, the University of Texas at Austin, Austin, 78712, USA.
推荐引用方式 GB/T 7714	Liao Yanran,Gai Yingying,Yao Yanjuan,et al. Validation methods of LAI products on the basis of scaling effect[J],2015,19(1):134-142.
APA	Liao Yanran,Gai Yingying,Yao Yanjuan,Fan Wenjie,Xu Xiru,&Yan Binyan.(2015).Validation methods of LAI products on the basis of scaling effect.Journal of Remote Sensing,19(1),134-142.
MLA	Liao Yanran,et al."Validation methods of LAI products on the basis of scaling effect".Journal of Remote Sensing 19.1(2015):134-142.