Modified vegetation indices for estimating crop fraction of absorbed photosynthetically active radiation

	Modified vegetation indices for estimating crop fraction of absorbed photosynthetically active radiation
	Dong, Taifeng 1; Meng, Jihua 1; Shang, Jiali 1; Liu, Jiangui 1; Wu, Bingfang 1; Huffman, Ted 1
刊名	INTERNATIONAL JOURNAL OF REMOTE SENSING
	2015
卷号	36 期号:12 页码:350-364
通讯作者	Wu, BF (reprint author), Chinese Acad Sci, Inst Remote Sensing & Digital Earth, Key Lab Digital Earth Sci, Div Digital Agr, Beijing, Peoples R China.
英文摘要	The fraction of absorbed photosynthetically active radiation (FPAR) is an important biophysical parameter of vegetation. It is often estimated using vegetation indices (VIs) derived from remote-sensing data, such as the normalized difference VI (NDVI). Ideally a linear relationship is used for the estimation; however, most conventional VIs are affected by canopy background reflectance and their sensitivity to FPAR declines at high biomass. In this study, a multiplier, the ratio of the green to the red reflectance, was introduced to improve the linear relationship between VIs and crop FPAR. Three widely used VIs - NDVI, the green normalized difference VI (GNDVI), and the renormalized difference VI (RDVI) - were modified this way and were called modified NDVI (MNDVI), modified GNDVI (MGNDVI), and modified RDVI (MRDVI), respectively. A sensitivity study was applied to analyse the correlation between the three modified indices and the leaf area index (LAI) using the reflectance data simulated by the combined PROSPECT leaf optical properties model and SAIL canopy bidirectional reflectance model (PROSAIL model). The results revealed that these new indices reduced the saturation trend at high LAI and achieved better linearity with crop LAI at low-to-medium biomass when compared with their corresponding original versions. This has also been validated using in situ FPAR measurements over wheat and maize crops. In particular, estimation using MNDVI achieved a coefficient of determination (R-2) of 0.97 for wheat and 0.86 for maize compared to 0.90 and 0.82 for NDVI, respectively, while MGNDVI achieved 0.97 for wheat and 0.88 for maize, compared to 0.90 and 0.81 for GNDVI, respectively. Algorithms based on the VIs when applied to both wheat and maize showed that MNDVI and MGNDVI achieved a better linearity relationship with FPAR (R-2 = 0.92), in comparison with NDVI (R-2 = 0.85) and GNDVI (R-2 = 0.82). The study demonstrated that applying the green to red reflectance ratio can improve the accuracy of FPAR estimation.
研究领域[WOS]	Remote Sensing ; Imaging Science & Photographic Technology
收录类别	SCI
语种	英语
WOS记录号	WOS:000357295800005
内容类型	期刊论文
源URL	[http://ir.ceode.ac.cn/handle/183411/38312]
专题	遥感与数字地球研究所_SCI/EI期刊论文_期刊论文
作者单位	1.[Dong, Taifeng 2.Meng, Jihua 3.Wu, Bingfang] Chinese Acad Sci, Inst Remote Sensing & Digital Earth, Key Lab Digital Earth Sci, Div Digital Agr, Beijing, Peoples R China 4.[Dong, Taifeng 5.Shang, Jiali 6.Liu, Jiangui 7.Huffman, Ted] Agr & Agri Food Canada, Eastern Cereal & Oilseed Res Ctr, Ottawa, ON, Canada
推荐引用方式 GB/T 7714	Dong, Taifeng,Meng, Jihua,Shang, Jiali,et al. Modified vegetation indices for estimating crop fraction of absorbed photosynthetically active radiation[J]. INTERNATIONAL JOURNAL OF REMOTE SENSING,2015,36(12):350-364.
APA	Dong, Taifeng,Meng, Jihua,Shang, Jiali,Liu, Jiangui,Wu, Bingfang,&Huffman, Ted.(2015).Modified vegetation indices for estimating crop fraction of absorbed photosynthetically active radiation.INTERNATIONAL JOURNAL OF REMOTE SENSING,36(12),350-364.
MLA	Dong, Taifeng,et al."Modified vegetation indices for estimating crop fraction of absorbed photosynthetically active radiation".INTERNATIONAL JOURNAL OF REMOTE SENSING 36.12(2015):350-364.