2024/10/06 by Raufu, Ibrahim Olatunji
#Copernicus DEM #Digital Elevation Model #NASADEM #accuracy assessment #terrain analysis
paper · doi:10.48346/imist.prsm/ajlp-gs.v7i4.49875
Context and background Digital elevation models (DEMs) are essential tools for a wide range of scientific and geospatial applications, providing critical data for elevation and terrain analysis. While remote sensing DEMs have gained popularity due to their extensive spatial coverage and detailed spectral characteristics, assessing their accuracy is crucial for ensuring the reliability of the information they provide. Goal and Objectives: This study aims to evaluate the accuracy and performance of various Digital Elevation Models (DEMs) for geospatial applications in Ibadan, Nigeria. The specific objectives are to assess the DEMs' accuracy using GPS point survey data and to identify the most suitable DEM for reliable topographic representation in the study area. Methodology: Seven DEMs were evaluated: Shuttle Radar Topography Mission with 30 m and 90 m resolution (SRTM30 and SRTM90), NASADEM with 30 m resolution, Copernicus DEM with 30 m and 90 m resolution (COP30 and COP90), Advanced Land Observing Satellite World 3D with 30 m resolution (AW3D30), and ALOS PALSAR with 12.5 m resolution. The DEMs' accuracy was assessed using mean error (ME), mean absolute error (MAE), standard deviation (STDE), and linear error metrics, validated against GPS point survey data. Results: The analysis revealed that AW3D30 consistently provided the highest accuracy, closely representing the actual terrain of Ibadan. NASADEM exhibited the lowest ME and MAE values, indicating high precision, while ALOS PALSAR demonstrated the greatest deviations, despite its STDE and linear error metrics being comparable to other models. This study underscores the importance of accuracy assessment for DEMs in geospatial applications and serves as a valuable reference for selecting appropriate DEMs for various geospatial tasks in Ibadan, Nigeria.