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DOI	10.1016/j.rse.2020.112110
	Validation of ICESat-2 terrain and canopy heights in boreal forests
	Neuenschwander A.; Guenther E.; White J.C.; Duncanson L.; Montesano P.
发表日期	2020
ISSN	00344257
卷号	251
英文摘要	NASA's Ice, Cloud and Land Elevation Satellite-2 (ICESat-2) launched in the fall of 2018 and is collecting vegetation canopy height and terrain measurements globally. In this paper we validate the terrain and canopy heights estimated from 11 months of ICESat-2 data using airborne lidar data collected in southern Finland. Overall, the terrain heights from the ATL08 data product agreed with the airborne lidar with vertical errors less than 75 cm (mean = −0.07 m; MAE = 0.53 m, RMSE = 0.73 m; n observations = 909,467). ATL08 terrain heights had positive bias (33 cm) when permanent snow cover was present compared to the airborne lidar. Canopy heights derived from ICESat-2 varied significantly by the beam selection (i.e. strong versus weak). Use of the weak beams increased the underestimation of canopy height by 1.06 m and increased RMSE% by 8.08%. The lowest canopy height errors were associated with strong beam/night/summer ATL08 acquisitions, which underestimated canopy height by 0.56 m (Bias% = 3.18; RMSE% of 13.75%), followed by strong beam/day/summer acquisitions (Bias% = 2.85%; RMSE% = 14.77%). For this study area with managed, coniferous-dominated boreal forests, we found that ATL08 canopy height errors were lowest for canopy cover ranging from 40 to 85% and within this range, we found that on average, ICESat-2 missed the top 11–13% of canopy heights. At low canopy cover (<40%), photons are more likely to be reflected from the terrain surface rather than the canopy due to the lower amount of vegetation present. Although not designed for canopy height retrievals, herein we have demonstrated that ICESat-2 can provide a useful source of canopy height information in boreal forests. By quantifying the accuracy with which terrain and canopy heights are characterized by ATL08, we provide insights on the capabilities and limitations of these data for these applications. Our results indicate that end users interested in canopy height retrievals in particular should avoid the use of weak beam data in boreal forest conditions. © 2020 The Author(s)
英文关键词	ATL08; Boreal; Canopy height; Forest; ICESat-2; LiDAR; Terrain; Validation
语种	英语
scopus关键词	Errors; Forestry; NASA; Optical radar; Snow; Vegetation; Airborne lidar data; Beam selection; Canopy heights; Ice , cloud and land elevation satellites; Southern Finland; Terrain height; Terrain surfaces; Vegetation canopy height; Landforms; airborne sensing; boreal forest; canopy architecture; forest management; ICESat; lidar; model validation; snow cover; terrain; Finland
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/179104
作者单位	Applied Research Laboratories, University of Texas at Austin, United States; Canadian Forest Service, (Pacific Forestry Centre), Natural Resources Canada, 506 West Burnside Road, Victoria, BC V8Z 1M5, Canada; Department of Geographical Sciences, University of Maryland, United States; Biospheric Sciences, NASA Goddard Space Flight Center, Greenbelt, MD, United States
推荐引用方式 GB/T 7714	Neuenschwander A.,Guenther E.,White J.C.,et al. Validation of ICESat-2 terrain and canopy heights in boreal forests[J],2020,251.
APA	Neuenschwander A.,Guenther E.,White J.C.,Duncanson L.,&Montesano P..(2020).Validation of ICESat-2 terrain and canopy heights in boreal forests.Remote Sensing of Environment,251.
MLA	Neuenschwander A.,et al."Validation of ICESat-2 terrain and canopy heights in boreal forests".Remote Sensing of Environment 251(2020).