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DOI	10.1016/j.jag.2018.10.017
	Reflectance variation in boreal landscape during the snow melting period using airborne imaging spectroscopy
	Heinilä K.; Salminen M.; Metsämäki S.; Pellikka P.; Koponen S.; Pulliainen J.
发表日期	2019
ISSN	15698432
起始页码	66
结束页码	76
卷号	76
英文摘要	We aim a better understanding of the effect of spring-time snow melt on the remotely sensed scene reflectance by using an extensive amount of optical spectral data obtained from an airborne hyperspectral campaign in Northern Finland. We investigate the behaviour of thin snow reflectance for different land cover types, such as open areas, boreal forests and treeless fells. Our results not only confirm the generally known fact that the reflectance of a melting thin snow layer is considerably lower than that of a thick snow layer, but we also present analyses of the reflectance variation over different land covers and in boreal forests as a function of canopy coverage. According to common knowledge, the highly variating reflectance spectra of partially transparent, most likely also contaminated thin snow pack weakens the performance of snow detection algorithms, in particular in the mapping of Fractional Snow Cover (FSC) during the end of the melting period. The obtained results directly support further development of the SCAmod algorithm for FSC retrieval, and can be likewise applied to develop other algorithms for optical satellite data (e.g. spectral unmixing methods), and to perform accuracy assessments for snow detection algorithms. A useful part of this work is the investigation of the competence of Normalized Difference Snow Index (NDSI) in snow detection in late spring, since it is widely used in snow mapping. We conclude, based on the spectral data analysis, that the NDSI -based snow mapping is more accurate in open areas than in forests. However, at the very end of the snow melting period the behavior of the NDSI becomes more unstable and unpredictable in non-forests with shallow snow, increasing the inaccuracy also in non-forested areas. For instance in peatbogs covered by melting snow layer (snow depth < 30 cm) the mean NDSI -0.6 was observed, having coefficient of variation as high as 70%, whereas for deeper snow packs the mean NDSI shows positive values. © 2018 The Authors
英文关键词	AISA; Boreal forest; Fell; FSC; Land cover classification; MODIS; NDSI; NDVI; Reflectance; SCE; Scene reflectance; Snow mapping; Snow melt; Spectroscopy
语种	英语
scopus关键词	accuracy assessment; airborne sensing; algorithm; boreal forest; image classification; land cover; landscape structure; mapping method; MODIS; NDVI; performance assessment; reflectance; satellite data; snowmelt; snowpack; Finland
来源期刊	International Journal of Applied Earth Observation and Geoinformation
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/156518
作者单位	Finnish Environment Institute, Latokartanonkaari 11, Helsinki, 00790, Finland; Finnish Meteorological Institute, P.O. Box 503, Helsinki, FI-00101, Finland; College of Global Change and Earth System Science, Beijing Normal University, Beijing, 1000875, China; Department of Geosciences and Geography, University of Helsinki, P.O. Box 64, Helsinki, FI-00014, Finland
推荐引用方式 GB/T 7714	Heinilä K.,Salminen M.,Metsämäki S.,et al. Reflectance variation in boreal landscape during the snow melting period using airborne imaging spectroscopy[J],2019,76.
APA	Heinilä K.,Salminen M.,Metsämäki S.,Pellikka P.,Koponen S.,&Pulliainen J..(2019).Reflectance variation in boreal landscape during the snow melting period using airborne imaging spectroscopy.International Journal of Applied Earth Observation and Geoinformation,76.
MLA	Heinilä K.,et al."Reflectance variation in boreal landscape during the snow melting period using airborne imaging spectroscopy".International Journal of Applied Earth Observation and Geoinformation 76(2019).