干旱区生态环境知识资源中心(Arid): Beyond Vertical Point Accuracy: Assessing Inter-pixel Consistency in 30 m Global DEMs for the Arid Central Andes

Arid

DOI	10.3389/feart.2021.758606
	Beyond Vertical Point Accuracy: Assessing Inter-pixel Consistency in 30 m Global DEMs for the Arid Central Andes
	Purinton, Benjamin; Bookhagen, Bodo
通讯作者	Purinton, B (corresponding author), Univ Potsdam, Inst Geosci, Potsdam, Germany.
来源期刊	FRONTIERS IN EARTH SCIENCE
EISSN	2296-6463
出版年	2021
卷号	9
英文摘要	Quantitative geomorphic research depends on accurate topographic data often collected via remote sensing. Lidar, and photogrammetric methods like structure-from-motion, provide the highest quality data for generating digital elevation models (DEMs). Unfortunately, these data are restricted to relatively small areas, and may be expensive or time-consuming to collect. Global and near-global DEMs with 1 arcsec (similar to 30 m) ground sampling from spaceborne radar and optical sensors offer an alternative gridded, continuous surface at the cost of resolution and accuracy. Accuracy is typically defined with respect to external datasets, often, but not always, in the form of point or profile measurements from sources like differential Global Navigation Satellite System (GNSS), spaceborne lidar (e.g., ICESat), and other geodetic measurements. Vertical point or profile accuracy metrics can miss the pixel-to-pixel variability (sometimes called DEM noise) that is unrelated to true topographic signal, but rather sensor-, orbital-, and/or processing-related artifacts. This is most concerning in selecting a DEM for geomorphic analysis, as this variability can affect derivatives of elevation (e.g., slope and curvature) and impact flow routing. We use (near) global DEMs at 1 arcsec resolution (SRTM, ASTER, ALOS, TanDEM-X, and the recently released Copernicus) and develop new internal accuracy metrics to assess inter-pixel variability without reference data. Our study area is in the arid, steep Central Andes, and is nearly vegetation-free, creating ideal conditions for remote sensing of the bare-earth surface. We use a novel hillshade-filtering approach to detrend long-wavelength topographic signals and accentuate short-wavelength variability. Fourier transformations of the spatial signal to the frequency domain allows us to quantify: 1) artifacts in the un-projected 1 arcsec DEMs at wavelengths greater than the Nyquist (twice the nominal resolution, so > 2 arcsec); and 2) the relative variance of adjacent pixels in DEMs resampled to 30-m resolution (UTM projected). We translate results into their impact on hillslope and channel slope calculations, and we highlight the quality of the five DEMs. We find that the Copernicus DEM, which is based on a carefully edited commercial version of the TanDEM-X, provides the highest quality landscape representation, and should become the preferred DEM for topographic analysis in areas without sufficient coverage of higher-quality local DEMs.
英文关键词	DEM noise Fourier analysis TanDEM-X ASTER GDEM Copernicus DEM WorldDEM SRTM ALOS World 3D
类型	Article
语种	英语
开放获取类型	gold
收录类别	SCI-E
WOS记录号	WOS:000710941200001
WOS关键词	DIGITAL ELEVATION MODEL ; STRUCTURE-FROM-MOTION ; TANDEM-X ; TOPOGRAPHIC ANALYSIS ; GRID-RESOLUTION ; DATA SETS ; SRTM ; VALIDATION ; EXTRACTION ; RIVER
WOS类目	Geosciences, Multidisciplinary
WOS研究方向	Geology
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/368303
作者单位	[Purinton, Benjamin; Bookhagen, Bodo] Univ Potsdam, Inst Geosci, Potsdam, Germany
推荐引用方式 GB/T 7714	Purinton, Benjamin,Bookhagen, Bodo. Beyond Vertical Point Accuracy: Assessing Inter-pixel Consistency in 30 m Global DEMs for the Arid Central Andes[J],2021,9.
APA	Purinton, Benjamin,&Bookhagen, Bodo.(2021).Beyond Vertical Point Accuracy: Assessing Inter-pixel Consistency in 30 m Global DEMs for the Arid Central Andes.FRONTIERS IN EARTH SCIENCE,9.
MLA	Purinton, Benjamin,et al."Beyond Vertical Point Accuracy: Assessing Inter-pixel Consistency in 30 m Global DEMs for the Arid Central Andes".FRONTIERS IN EARTH SCIENCE 9(2021).