气候变化领域集成服务门户(CCPortal): Active-layer thickness estimation from X-band SAR backscatter intensity

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DOI	10.5194/tc-11-483-2017
	Active-layer thickness estimation from X-band SAR backscatter intensity
	Widhalm B.; Bartsch A.; Leibman M.; Khomutov A.
发表日期	2017
ISSN	19940416
卷号	11 期号:1
英文摘要	The active layer above the permafrost, which seasonally thaws during summer, is an important parameter for monitoring the state of permafrost. Its thickness is typically measured locally, but a range of methods which utilize information from satellite data exist. Mostly, the normalized difference vegetation index (NDVI) obtained from optical satellite data is used as a proxy. The applicability has been demonstrated mostly for shallow depths of active-layer thickness (ALT) below approximately 70 cm. Some permafrost areas including central Yamal are, however, characterized by larger ALT. Surface properties including vegetation structure are also represented by microwave backscatter intensity. So far, the potential of such data for estimating ALT has not been explored. We therefore investigated the relationship between ALT and X-band synthetic aperture radar (SAR) backscatter of TerraSAR-X (averages for 10 x10m window) in order to examine the possibility of delineating ALT with continuous and larger spatial coverage in this area and compare it to the already-established method of using NDVI from Landsat (30 m). Our results show that the mutual dependency of ALT and TerraSAR-X backscatter on land cover types suggests a connection of both parameters. A range of 5 dB can be observed for an ALT range of 100 cm (40-140 cm), and an R2 of 0.66 has been determined over the calibration sites. An increase of ALT with increasing backscatter can be determined. The root mean square error (RMSE) over a comparably heterogeneous validation site with maximum ALT of >150 cm is 20 cm. Deviations are larger for measurement locations with mixed vegetation types (especially partial coverage by cryptogam crust) with respect to the spatial resolution of the satellite data. © Author(s) 2017.
学科领域	active layer; backscatter; estimation method; ice thickness; Landsat; NDVI; permafrost; satellite data; synthetic aperture radar; Terra (satellite); vegetation structure; Russian Federation; Yamal Peninsula; Yamalo-Nenets
语种	英语
scopus关键词	active layer; backscatter; estimation method; ice thickness; Landsat; NDVI; permafrost; satellite data; synthetic aperture radar; Terra (satellite); vegetation structure; Russian Federation; Yamal Peninsula; Yamalo-Nenets
来源期刊	Cryosphere
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/119440
作者单位	Zentralanstalt für Meteorologie und Geodynamik, Division Data, Methods and Modelling, Vienna, 1190, Austria; Vienna University of Technology, Department of Geodesy and Geoinformation, Vienna, 1040, Austria; Earth Cryosphere Institute, Russian Academy of Sciences, Siberian Branch, Tyumen, 625000, Russian Federation; Tyumen State University, Department of Cryosophy, Tyumen, 625006, Russian Federation
推荐引用方式 GB/T 7714	Widhalm B.,Bartsch A.,Leibman M.,et al. Active-layer thickness estimation from X-band SAR backscatter intensity[J],2017,11(1).
APA	Widhalm B.,Bartsch A.,Leibman M.,&Khomutov A..(2017).Active-layer thickness estimation from X-band SAR backscatter intensity.Cryosphere,11(1).
MLA	Widhalm B.,et al."Active-layer thickness estimation from X-band SAR backscatter intensity".Cryosphere 11.1(2017).