气候变化领域集成服务门户(CCPortal): Evaluation of global leaf area index and fraction of absorbed photosynthetically active radiation products over North America using Copernicus Ground Based Observations for Validation data

CCPortal

DOI	10.1016/j.rse.2020.111935
	Evaluation of global leaf area index and fraction of absorbed photosynthetically active radiation products over North America using Copernicus Ground Based Observations for Validation data
	Brown L.A.; Meier C.; Morris H.; Pastor-Guzman J.; Bai G.; Lerebourg C.; Gobron N.; Lanconelli C.; Clerici M.; Dash J.
发表日期	2020
ISSN	00344257
卷号	247
英文摘要	With a growing number of Earth observation (EO) products available through operational programmes such as the European Union's Copernicus, there is increasing emphasis on product accuracy and uncertainty, necessitating evaluation against in situ reference measurements. Whilst existing reference datasets have proven a valuable resource, they incorporate little data with which products from recent EO instruments can be assessed. A reliance on individual field campaigns has also led to several inconsistencies, whilst limiting the extent to which temporal variations in EO product performance can be captured. Recently established environmental monitoring networks such as the National Ecological Observatory Network (NEON), which collect routine in situ measurements using standardised instruments and protocols, provide a promising opportunity in this respect. The Copernicus Ground Based Observations for Validation (GBOV) service was initiated in recognition of this fact. In the first component of the project, raw observations from existing networks have been collected and processed to provide reference data for a range of EO land products. In this study, we focus on leaf area index (LAI) and the fraction of absorbed photosynthetically active radiation (FAPAR). Raw digital hemispherical photography (DHP) from twenty NEON sites was processed to derive in situ reference measurements, which were then upscaled to provide high spatial resolution reference maps. Using these data, we assess the recently released Copernicus Global Land Service (CGLS) 300 m Version 1 (V1) products derived from PROBA-V, in addition to existing products derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) and Visible Infrared Radiometer Suite (VIIRS). When evaluated against reference data, the CGLS 300 m V1 product demonstrated the best agreement (RMSD = 0.57 for LAI and 0.08 for FAPAR), followed by the Collection 6 VNP15A2H and MOD15A2H products (RMSD = 0.81 to 0.89 for LAI and 0.12 for FAPAR). Differing assumptions of the products and in situ reference measurements, which cause them to be sensitive to slightly different quantities, are thought to explain apparent biases over sparse vegetation and forest environments. To ensure their continued utility, future work should focus on updating the GBOV in situ reference measurements, implementing additional corrections, and improving their geographical representativeness. © 2020 The Authors
英文关键词	Copernicus; digital hemispherical photography; FAPAR; GBOV; LAI; MODIS; PROBA-V; validation; VIIRS
语种	英语
scopus关键词	Forestry; Neon; Radiometers; Solar radiation; Temperature measurement; Earth observation products; Environmental Monitoring; Ground-based observations; Hemispherical photography; High spatial resolution; Moderate resolution imaging spectroradiometer; Operational programmes; Photosynthetically active radiation; Uncertainty analysis; accuracy assessment; data processing; European Union; global perspective; ground-based measurement; in situ measurement; leaf area index; model validation; MODIS; photosynthetically active radiation; satellite data; spatial resolution; VIIRS; North America
来源期刊	Remote Sensing of Environment
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/179232
作者单位	School of Geography and Environmental Science, University of Southampton, Highfield, Southampton, SO17 1BJ, United Kingdom; National Ecological Observatory Network, Boulder, CO 80301, United States; ACRI-ST, Sophia-Antipolis, 06904, France; European Commission Joint Research Centre, Ispra, 21027, Italy
推荐引用方式 GB/T 7714	Brown L.A.,Meier C.,Morris H.,et al. Evaluation of global leaf area index and fraction of absorbed photosynthetically active radiation products over North America using Copernicus Ground Based Observations for Validation data[J],2020,247.
APA	Brown L.A..,Meier C..,Morris H..,Pastor-Guzman J..,Bai G..,...&Dash J..(2020).Evaluation of global leaf area index and fraction of absorbed photosynthetically active radiation products over North America using Copernicus Ground Based Observations for Validation data.Remote Sensing of Environment,247.
MLA	Brown L.A.,et al."Evaluation of global leaf area index and fraction of absorbed photosynthetically active radiation products over North America using Copernicus Ground Based Observations for Validation data".Remote Sensing of Environment 247(2020).