气候变化领域集成服务门户(CCPortal): How will radar layover impact SWOT measurements of water surface elevation and slope, and estimates of river discharge?

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DOI	10.1016/j.rse.2020.111883
	How will radar layover impact SWOT measurements of water surface elevation and slope, and estimates of river discharge?
	Durand M.; Chen C.; de Moraes Frasson R.P.; Pavelsky T.M.; Williams B.; Yang X.; Fore A.
发表日期	2020
ISSN	00344257
卷号	247
英文摘要	Water surface elevation (WSE), slope and width measurements from the forthcoming Surface Water and Ocean Topography (SWOT) mission will enable spaceborne estimates of global river discharge. WSE will be measured by interferometric synthetic aperture radar (InSAR). InSAR measurements are vulnerable to contamination from layover, a phenomenon wherein radar returns from multiple locations arrive at the sensor simultaneously, rendering them indistinguishable. This study assesses whether layover will significantly impact the precision of SWOT estimates of global river discharge. We present a theoretical river layover uncertainty model at the scale of nodes and reaches, which constitute nominal 200 m and 10 km averages, respectively, along river centerlines. The model is calibrated using high-resolution simulations of SWOT radar interaction with topography covering a total of 41,233 node observations, across a wide range of near-river topographic features. We find that height uncertainty increases to a maximum value at relatively low values of topographic standard deviation and varies strongly with position in the swath. When applied at global scale, the calibrated model shows that layover causes expected height uncertainty to increase by only a modest amount (from 9.4 to 10.4 cm at the 68th percentile). The 68th percentile of the slope uncertainty increases more significantly, from 10 to 17 mm/km. Nonetheless, the 68th percentile discharge uncertainty increases only marginally. We find that the impact of layover on SWOT river discharge is expected to be small in most environments. © 2020 Elsevier Inc.
英文关键词	Radar interferometry; River hydrology
语种	英语
scopus关键词	Rivers; Synthetic aperture radar; Topography; High resolution simulations; Interferometric synthetic aperture radars; Radar interactions; Standard deviation; Topographic features; Uncertainty modeling; Water surface elevations; Width measurements; Radar measurement; elevation; estimation method; measurement method; river discharge; satellite mission; satellite sensor; surface water; synthetic aperture radar
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/179219
作者单位	The Ohio State University, School of Earth Sciences and Byrd Polar and Climate Research Center, Columbus, 43214, United States; NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, 91109, United States; Department of Geological Sciences, University of North Carolina, Chapel Hill, 27599-3315, United States
推荐引用方式 GB/T 7714	Durand M.,Chen C.,de Moraes Frasson R.P.,et al. How will radar layover impact SWOT measurements of water surface elevation and slope, and estimates of river discharge?[J],2020,247.
APA	Durand M..,Chen C..,de Moraes Frasson R.P..,Pavelsky T.M..,Williams B..,...&Fore A..(2020).How will radar layover impact SWOT measurements of water surface elevation and slope, and estimates of river discharge?.Remote Sensing of Environment,247.
MLA	Durand M.,et al."How will radar layover impact SWOT measurements of water surface elevation and slope, and estimates of river discharge?".Remote Sensing of Environment 247(2020).