气候变化领域集成服务门户(CCPortal): Analysis of Sentinel-3 SAR altimetry waveform retracking algorithms for deriving temporally consistent water levels over ice-covered lakes

CCPortal

DOI	10.1016/j.rse.2020.111643
	Analysis of Sentinel-3 SAR altimetry waveform retracking algorithms for deriving temporally consistent water levels over ice-covered lakes
	Shu S.; Liu H.; Beck R.A.; Frappart F.; Korhonen J.; Xu M.; Yang B.; Hinkel K.M.; Huang Y.; Yu B.
发表日期	2020
ISSN	00344257
卷号	239
英文摘要	Satellite radar altimetry has been widely used in the monitoring of water levels of lakes, rivers and wetlands in the past decades. The conventional pulse-limited radar altimeters have a relatively large ground footprint, which limits their capability to retrieve surface elevation information over small and medium-sized water bodies. A new generation of satellite radar altimeter system, a dual-frequency SAR radar altimeter (SRAL) onboard the Copernicus Sentinel-3 satellite, has produced densely sampled elevation measurements with a smaller footprint for the Earth's surfaces since June 2016, owing to the Delay-Doppler processing technique. Four standard SRAL SAR altimetry waveform retracking algorithms (known as retrackers) have been designed to retrieve elevation measurements for different types of surfaces: Ice-Sheet retracker for polar ice sheets, SAMOSA-3 retracker for open ocean and coastal zones, OCOG retracker for sea-ice margins, and Sea-Ice retracker for sea ice. In this research, we evaluated the performances of the Sentinel-3 SRAL SAR altimetry retrackers over lakes, particularly over seasonally ice-covered lakes in one hydrological cycle. For 15 lakes and reservoirs with different sizes and at varying latitudes in the northern hemisphere, we compared the lake water levels estimated by each of standard SRAL SAR retrackers against in-situ water level measurements for different seasons (a full hydrologic cycle) during 2016–2017. Our evaluation shows that Sea-Ice retracker was unable to provide continuous estimates of lake water levels, as a result of the high rate of missing data. Although the precision and relative accuracy of lake water level estimates from these three standard SRAL SAR retrackers are similar, the SAMOSA-3 retracker has the least bias in comparison with ground-based gauge measurements. When the lakes in the mid- and high-latitude regions were covered by ice in the winter season, these three standard SAR retrackers generated erroneous lake water level measurements, significantly lower than the true lake water levels recorded by in-situ gauge stations. The measurement errors of these three standard retrackers increase with the growth of the lake ice thickness. To address the negative effect of the seasonal ice cover, we developed a new bimodal correction algorithm. We demonstrate that our bimodal correction algorithm can retrieve the ice thickness and reliably estimate water levels for the ice-covered lakes in winter, hence enabling the generation of temporally consistent lake water level measurements throughout all seasons for lake hydrological analysis. © 2020 Elsevier Inc.
英文关键词	Ice cover; Lake water levels; SAR altimetry; Sentinel-3; Waveform
语种	英语
scopus关键词	Aneroid altimeters; Coastal zones; Gages; Glaciers; Lakes; Level measurement; Meteorological instruments; Radar equipment; Radar measurement; Radio altimeters; Satellites; Sea ice; Space-based radar; Synthetic aperture radar; Water levels; Ice cover; Lake water level; SAR altimetry; Sentinel-3; Wave forms; Reservoirs (water); algorithm; data processing; Doppler radar; hydrological cycle; ice cover; lake water; radar altimetry; sea ice; Sentinel; synthetic aperture radar; tracking; water level; waveform analysis
来源期刊	Remote Sensing of Environment
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/179450
作者单位	Department of Geography and Planning, Appalachian State University, Boone, NC 28608, United States; Department of Geography, the University of Alabama, Tuscaloosa, AL 35487, United States; Key Laboratory of Geographical Information Science, Ministry of Education, School of Geographical Science, East China Normal University, Shanghai, 200241, China; Department of Geography and Geographic Information Science, University of Cincinnati, Cincinnati, OH 45221, United States; Laboratoire d'Etudes en Géophysique et Océanographie Spatiales (LEGOS), UMR 5566, CNRS/IRD/UPS, OMP, 14 Avenue Édouard Belin, Toulouse, 31400, France; Finnish Environment Institute, SYKE, Freshwater Center, P.O Box 140, Helsinki, 00251, Finland; Department of Sociology, University of Central Florida, Orlando, FL 32816, United States
推荐引用方式 GB/T 7714	Shu S.,Liu H.,Beck R.A.,et al. Analysis of Sentinel-3 SAR altimetry waveform retracking algorithms for deriving temporally consistent water levels over ice-covered lakes[J],2020,239.
APA	Shu S..,Liu H..,Beck R.A..,Frappart F..,Korhonen J..,...&Yu B..(2020).Analysis of Sentinel-3 SAR altimetry waveform retracking algorithms for deriving temporally consistent water levels over ice-covered lakes.Remote Sensing of Environment,239.
MLA	Shu S.,et al."Analysis of Sentinel-3 SAR altimetry waveform retracking algorithms for deriving temporally consistent water levels over ice-covered lakes".Remote Sensing of Environment 239(2020).