DOI: 10.5194/tc-11-755-2017
Scopus记录号: 2-s2.0-85016253196
论文题名: Signature of Arctic first-year ice melt pond fraction in X-band SAR imagery
作者: Fors A ; S ; , Divine D ; V ; , Doulgeris A ; P ; , Renner A ; H ; H ; , Gerland S
刊名: Cryosphere
ISSN: 19940416
出版年: 2017
卷: 11, 期: 2 起始页码: 755
结束页码: 771
语种: 英语
英文关键词: backscatter
; noise
; pixel
; polarization
; satellite altimetry
; sea ice
; synthetic aperture radar
; wind velocity
; Arctic
英文摘要: In this paper we investigate the potential of melt pond fraction retrieval from X-band polarimetric synthetic aperture radar (SAR) on drifting first-year sea ice. Melt pond fractions retrieved from a helicopter-borne camera system were compared to polarimetric features extracted from four dual-polarimetric X-band SAR scenes, revealing significant relationships. The correlations were strongly dependent on wind speed and SAR incidence angle. Co-polarisation ratio was found to be the most promising SAR feature for melt pond fraction estimation at intermediate wind speeds (6. 2ms-1), with a Spearman's correlation coefficient of 0. 46. At low wind speeds (0. 6ms-1), this relation disappeared due to low backscatter from the melt ponds, and backscatter VV-polarisation intensity had the strongest relationship to melt pond fraction with a correlation coefficient of-0. 53. To further investigate these relations, regression fits were made both for the intermediate (R2fit Combining double low line 0. 21) and low (R2fit Combining double low line 0. 26) wind case, and the fits were tested on the satellite scenes in the study. The regression fits gave good estimates of mean melt pond fraction for the full satellite scenes, with less than 4% from a similar statistics derived from analysis of low-altitude imagery captured during helicopter ice-survey flights in the study area. A smoothing window of 51 × 51 pixels gave the best reproduction of the width of the melt pond fraction distribution. A considerable part of the backscatter signal was below the noise floor at SAR incidence angles above ∼ 40°, restricting the information gain from polarimetric features above this threshold. Compared to previous studies in C-band, limitations concerning wind speed and noise floor set stricter constraints on melt pond fraction retrieval in X-band. Despite this, our findings suggest new possibilities in melt pond fraction estimation from X-band SAR, opening for expanded monitoring of melt ponds during melt season in the future. © 2017 Author(s). Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/75581
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: Department of Physics and Technology, University of Tromsø, Arctic University of Norway, Tromsø, Norway; Norwegian Polar Institute, FRAM Centre, Tromsø, Norway; Department of Mathematics and Statistics, University of Tromsø, Arctic University of Norway, Tromsø, Norway; Institute of Marine Research, Tromsø, Norway
Recommended Citation:
Fors A,S,, Divine D,et al. Signature of Arctic first-year ice melt pond fraction in X-band SAR imagery[J]. Cryosphere,2017-01-01,11(2)