DOI: 10.5194/tc-11-483-2017
Scopus记录号: 2-s2.0-85012271916
论文题名: Active-layer thickness estimation from X-band SAR backscatter intensity
作者: Widhalm B ; , Bartsch A ; , Leibman M ; , Khomutov A
刊名: Cryosphere
ISSN: 19940416
出版年: 2017
卷: 11, 期: 1 起始页码: 483
结束页码: 496
语种: 英语
英文关键词: 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
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. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/75598
Appears in Collections: 影响、适应和脆弱性 气候变化与战略
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作者单位: Zentralanstalt für Meteorologie und Geodynamik, Division Data, Methods and Modelling, Vienna, Austria; Vienna University of Technology, Department of Geodesy and Geoinformation, Vienna, Austria; Earth Cryosphere Institute, Russian Academy of Sciences, Siberian Branch, Tyumen, Russian Federation; Tyumen State University, Department of Cryosophy, Tyumen, Russian Federation
Recommended Citation:
Widhalm B,, Bartsch A,, Leibman M,et al. Active-layer thickness estimation from X-band SAR backscatter intensity[J]. Cryosphere,2017-01-01,11(1)