DOI: 10.1016/j.jag.2016.05.006
Scopus记录号: 2-s2.0-84997673899
论文题名: L-band Synthetic Aperture Radar imagery performs better than optical datasets at retrieving woody fractional cover in deciduous, dry savannahs
作者: Naidoo L ; , Mathieu R ; , Main R ; , Wessels K ; , Asner G ; P
刊名: International Journal of Applied Earth Observation and Geoinformation
ISSN: 15698432
出版年: 2016
卷: 52 起始页码: 54
结束页码: 64
语种: 英语
英文关键词: LandSAT-5
; Random Forest
; SAR
; Spectral vegetation indices
; Textures
; Woody canopy cover
Scopus关键词: ALOS
; image analysis
; Landsat
; machine learning
; PALSAR
; radar imagery
; savanna
; synthetic aperture radar
; vegetation cover
; South Africa
英文摘要: Woody canopy cover (CC) is the simplest two dimensional metric for assessing the presence of the woody component in savannahs, but detailed validated maps are not currently available in southern African savannahs. A number of international EO programs (including in savannah landscapes) advocate and use optical LandSAT imagery for regional to country-wide mapping of woody canopy cover. However, previous research has shown that L-band Synthetic Aperture Radar (SAR) provides good performance at retrieving woody canopy cover in southern African savannahs. This study's objective was to evaluate, compare and use in combination L-band ALOS PALSAR and LandSAT-5 TM, in a Random Forest environment, to assess the benefits of using LandSAT compared to ALOS PALSAR. Additional objectives saw the testing of LandSAT-5 image seasonality, spectral vegetation indices and image textures for improved CC modelling. Results showed that LandSAT-5 imagery acquired in the summer and autumn seasons yielded the highest single season modelling accuracies (R2 between 0.47 and 0.65), depending on the year but the combination of multi-seasonal images yielded higher accuracies (R2 between 0.57 and 0.72). The derivation of spectral vegetation indices and image textures and their combinations with optical reflectance bands provided minimal improvement with no optical-only result exceeding the winter SAR L-band backscatter alone results (R2 of ∼0.8). The integration of seasonally appropriate LandSAT-5 image reflectance and L-band HH and HV backscatter data does provide a significant improvement for CC modelling at the higher end of the model performance (R2 between 0.83 and 0.88), but we conclude that L-band only based CC modelling be recommended for South African regions. © 2016 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/80030
Appears in Collections: 气候变化事实与影响
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作者单位: Ecosystem Earth Observation, Natural Resources and the Environment, CSIR, Pretoria, South Africa; Department of Geography, Geoinformatics and Meteorology, University of Pretoria, Pretoria, South Africa; Remote Sensing Unit, Meraka Institute, CSIR, Pretoria, South Africa; Department of Global Ecology, Carnegie Institution for Science, Stanford, CA, United States
Recommended Citation:
Naidoo L,, Mathieu R,, Main R,et al. L-band Synthetic Aperture Radar imagery performs better than optical datasets at retrieving woody fractional cover in deciduous, dry savannahs[J]. International Journal of Applied Earth Observation and Geoinformation,2016-01-01,52