2025/12/07 by Mohamed Helmy, Emanuele Mandanici, Luca Vittuari +1
paper · doi:10.1177/03091333251406853
Digital Terrain Models (DTMs) are essential representations of Earth’s surface, widely used in topographic mapping, hydrological modeling, engineering, and hazard assessment. Advances in satellite imagery, LiDAR, and interpolation techniques have significantly improved DTM generation. This study evaluates the vertical accuracy of four global, freely available DEMs, SRTM 30, ALOS World 3D, Copernicus 30, as DSMs and FABDEM as a DTM, against high-resolution LiDAR-derived reference data across three diverse case study areas in Italy: urban, mountainous, and flat terrains. The assessment framework combined pixel-wise error statistics with zonal analysis using the 2023 ESRI Land Cover dataset. Results highlight that terrain morphology and land cover significantly affect DTM accuracy. Copernicus 30 and FABDEM outperformed the others overall, showing low mean elevation errors and consistent performance across landscape types. Copernicus 30 achieved high accuracy in urban areas (mean difference: 0.48 m), while FABDEM performed well in vegetated and mixed terrains (1.48 m and −0.87 m in Trentino-Alto Adige and Valle d’Aosta, respectively), benefiting from vegetation and building artifact removal. ALOS World 3D showed the poorest performance, with high errors in forested and urban areas, failing to meet its nominal vertical accuracy threshold (