DOI: 10.1016/j.jag.2016.09.008
Scopus记录号: 2-s2.0-85018662122
论文题名: Canopy foliar nitrogen retrieved from airborne hyperspectral imagery by correcting for canopy structure effects
作者: Wang Z ; , Skidmore A ; K ; , Wang T ; , Darvishzadeh R ; , Heiden U ; , Heurich M ; , Latifi H ; , Hearne J
刊名: International Journal of Applied Earth Observation and Geoinformation
ISSN: 15698432
出版年: 2017
卷: 54 起始页码: 84
结束页码: 94
语种: 英语
英文关键词: Essential biodiversity variables
; Foliar nitrogen
; Forest canopy structure
; Hyperspectral remote sensing
Scopus关键词: airborne sensing
; biodiversity
; canopy
; leaf area
; nitrogen
; remote sensing
; spectral analysis
; wavelet analysis
英文摘要: A statistical relationship between canopy mass-based foliar nitrogen concentration (%N) and canopy bidirectional reflectance factor (BRF) has been repeatedly demonstrated. However, the interaction between leaf properties and canopy structure confounds the estimation of foliar nitrogen. The canopy scattering coefficient (the ratio of BRF and the directional area scattering factor, DASF) has recently been suggested for estimating %N as it suppresses the canopy structural effects on BRF. However, estimation of %N using the scattering coefficient has not yet been investigated for longer spectral wavelengths (>855 nm). We retrieved the canopy scattering coefficient for wavelengths between 400 and 2500 nm from airborne hyperspectral imagery, and then applied a continuous wavelet analysis (CWA) to the scattering coefficient in order to estimate %N. Predictions of %N were also made using partial least squares regression (PLSR). We found that %N can be accurately retrieved using CWA (R2 = 0.65, RMSE = 0.33) when four wavelet features are combined, with CWA yielding a more accurate estimation than PLSR (R2 = 0.47, RMSE = 0.41). We also found that the wavelet features most sensitive to %N variation in the visible region relate to chlorophyll absorption, while wavelet features in the shortwave infrared regions relate to protein and dry matter absorption. Our results confirm that %N can be retrieved using the scattering coefficient after correcting for canopy structural effect. With the aid of high-fidelity airborne or upcoming space-borne hyperspectral imagery, large-scale foliar nitrogen maps can be generated to improve the modeling of ecosystem processes as well as ecosystem-climate feedbacks. © 2016 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/79944
Appears in Collections: 气候变化事实与影响
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作者单位: Faculty of Geo-Information Science and Earth Observation (ITC), University of Twente, P.O. Box 217, Enschede, Netherlands; School of Mathematical and Geospatial Sciences, RMIT University, GPO Box 2476, Melbourne, Victoria, Australia; Department of Land Surface, German Remote Sensing Data Center (DFD), German Aerospace Center (DLR), Oberpfaffenhofen, Wessling, Germany; Bavarian Forest National Park, Freyunger Straße 2, Grafenau, Germany; Department of Remote Sensing in Cooperation with German Aerospace Center, University of Würzburg, Oswald-Külpe-Weg 86, Würzburg, Germany
Recommended Citation:
Wang Z,, Skidmore A,K,et al. Canopy foliar nitrogen retrieved from airborne hyperspectral imagery by correcting for canopy structure effects[J]. International Journal of Applied Earth Observation and Geoinformation,2017-01-01,54