Assessment of the global Copernicus, NASADEM, ASTER and AW3D digital elevation models in Central and Southern Africa

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dc.contributor.author Okolie, Chukwuma J.
dc.contributor.author Mills, Jon P.
dc.contributor.author Adeleke, Adedayo
dc.contributor.author Smit, Julian L.
dc.contributor.author Peppa, Maria V.
dc.contributor.author Altunel, Arif O.
dc.contributor.author Arungwa, Ikenna D.
dc.date.accessioned 2024-10-21T08:07:43Z
dc.date.available 2024-10-21T08:07:43Z
dc.date.issued 2024
dc.description DATA AVAILABILITY STATEMENT : The data that support the findings of this study are available from the corresponding author upon reasonable request. en_US
dc.description.abstract Validation studies of global Digital Elevation Models (DEMs) in the existing literature are limited by the diversity and spread of landscapes, terrain types considered and sparseness of groundtruth. Moreover, there are knowledge gaps on the accuracy variations in rugged and complex landscapes, and previous studies have often not relied on robust internal and external validation measures. Thus, there is still only partial understanding and limited perspective of the reliability and adequacy of global DEMs for several applications. In this study, we utilize a dense spread of LiDAR groundtruth to assess the vertical accuracies of four medium-resolution, readily available, free-access and global coverage 1 arc-second (30 m) DEMs: NASADEM, ASTER GDEM, Copernicus GLO-30, and ALOS World 3D (AW3D). The assessment is carried out at landscapes spread across Cape Town, Southern Africa (urban/industrial, agricultural, mountain, peninsula and grassland/shrubland) and forested national parks in Gabon, Central Africa (low-relief tropical rainforest and high-relief tropical rainforest). The statistical analysis is based on robust accuracy metrics that cater for normal and non-normal elevation error distribution, and error ranking. In Cape Town, Copernicus DEM generally had the least vertical error with an overall Mean Error (ME) of 0.82 m and Root Mean Square Error (RMSE) of 2.34 m while ASTER DEM had the poorest performance. However, ASTER GDEM and NASADEM performed better in the low-relief and high-relief tropical forests of Gabon. Generally, the DEM errors have a moderate to high positive correlation in forests, and a low to moderate positive correlation in mountains and urban areas. Copernicus DEM showed superior vertical accuracy in forests with less than 40% tree cover, while ASTER and NASADEM performed better in denser forests with tree cover greater than 70%. This study is a robust regional assessment of these global DEMs. en_US
dc.description.department Geography, Geoinformatics and Meteorology en_US
dc.description.librarian hj2024 en_US
dc.description.sdg SDG-15:Life on land en_US
dc.description.sponsorship The Commonwealth Scholarship Commission and the Foreign, Commonwealth and Development Office in the UK and the University of Cape Town Postgraduate Funding Office. en_US
dc.description.uri https://www.tandfonline.com/loi/tgsi20 en_US
dc.identifier.citation Chukwuma J. Okolie, Jon P. Mills, Adedayo K. Adeleke, Julian L. Smit, Maria V. Peppa, Arif O. Altunel & Ikenna D. Arungwa (2024) Assessment of the global Copernicus, NASADEM, ASTER and AW3D digital elevation models in Central and Southern Africa, Geo-spatial Information Science, 27:4, 1362-1390, DOI: 10.1080/10095020.2023.2296010. en_US
dc.identifier.issn 1009-5020 (print)
dc.identifier.issn 1993-5153 (online)
dc.identifier.other 10.1080/10095020.2023.2296010
dc.identifier.uri http://hdl.handle.net/2263/98677
dc.language.iso en en_US
dc.publisher Taylor and Francis en_US
dc.rights © 2024 Wuhan University. Published by Informa UK Limited, trading as Taylor & Francis Group. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/). en_US
dc.subject Digital elevation model (DEM) en_US
dc.subject Global digital elevation model en_US
dc.subject NASADEM en_US
dc.subject ALOS World 3D en_US
dc.subject Copernicus en_US
dc.subject LiDAR en_US
dc.subject NASA land vegetation and ice sensor (LVIS) en_US
dc.subject Height error map en_US
dc.subject National Aeronautics and Space Administration (NASA) en_US
dc.subject Advanced spaceborne thermal emission and reflection radiometer (ASTER) en_US
dc.subject Shuttle radar topography mission (SRTM) en_US
dc.subject SDG-15: Life on land en_US
dc.title Assessment of the global Copernicus, NASADEM, ASTER and AW3D digital elevation models in Central and Southern Africa en_US
dc.type Article en_US


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