DEMIX GIS Database Version 3.5

This was developed for this paper Guth, P.L.; Trevisani, S.; Grohmann, C.H.; Lindsay, J.B.; Reuter, H.I. Benchmarking Elevation Plus Land Surface Parameters Finds FathomDEM and Copernicus DEM Win as Best Global DEMs. Remote Sens. 2025, 17, 3919. https://doi.org/10.3390/rs17233919 A much better version of this database is Version 4. Use this one only if you want to compare the evolution of GEDTM, but overall you should wait for a new version of GEDTM. Guth, P. (2025). DEMIX GIS Database Version 4 (Version 4) [Data set]. Zenodo. https://doi.org/10.5281/zenodo.17538186 This database supports the work of the Digital Elevation Model Intercomparison eXperiment (DEMIX) working group (Strobl and others, 2021; Guth and others, 2021; Bielski and others, 2024). The four files have the database tables in CSV format. Difference distributions for elevation, slope, and surface roughness. The provides continuity with \cite{BielskiOthers2024, GuthOthers2024}; for readers who want, it has the statistics like RMSE and LE90 for elevation and two LSPs, as well as the signed mean and median differences. FUV for a mixed suite of LSPs chosen to sample the full range of LSPs calculated from DEMs. These provide a better rankings of the test DEMs, and provides an estimate of the robustness of LSPs and suggest that some should be used with caution. FUV for the partial derivatives used for slope, aspect, and curvature. FUV for the suite of integrated curvature measures (Minar and others, 2020). This version adds to CopDEM, ALOS AW3D30, and FABDEM: FathomDEM (Uhe and others, 2025) EDTM 1.1 (https://s3.eu-central-1.wasabisys.com/openlandmap/dtm/dtm.bareearth_ensemble_p10_30m_s_2018_go_epsg4326_v20230221.tif, https://doi.org/10.5281/zenodo.7676373) GEDTM 1.2—this is the best version of 1.2 (there are at least two others, which have no scaling for the elevations) (https://s3.opengeohub.org/global/dtm/v1.2/gedtm_rf_m_30m_s_20060101_20151231_go_epsg.4326.3855_v1.2.tif GEDTM 1.1—this has 0.9” (about 30 yards instead of 30 meters) spacing https://s3.opengeohub.org/global/edtm/gedtm_rf_m_30m_s_20060101_20151231_go_epsg.4326.3855_v20250611.tif, https://doi.org/10.5281/zenodo.15689805 GEDTM v 0—this has 0.9” spacing https://s3.opengeohub.org/global/edtm/legendtm_rf_30m_m_s_20000101_20231231_go_epsg.4326_v20250130.tif, https://doi.org/10.5281/zenodo.14900181 The database contains 1381 tiles, about 10x10 km, in 140 areas. The tiles are based on the local projected grid, a change from earlier versions of the DEMIX database which used geographic outlines. It does not consider the low altitude coastal DEMs; for those use version 3 (https://zenodo.org/records/13331458 ). References: Bielski, C.; López-Vázquez, C.; Grohmann, C.H.; Guth. P.L.; Hawker, L.; Gesch, D.; Trevisani, S.; Herrera-Cruz, V.; Riazanoff, S.; Corseaux, A.; Reuter, H.; Strobl, P., 2024. Novel approach for ranking DEMs: Copernicus DEM improves one arc second open global topography. IEEE Transactions on Geoscience & Remote Sensing. vol. 62, pp. 1-22, 2024, Art no. 4503922, https://doi.org/10.1109/TGRS.2024.3368015 Guth, P.L.; Trevisani, S.; Grohmann, C.H.; Lindsay, J.; Gesch, D.; Hawker, L.; Bielski, C. Ranking of 10 Global One-Arc-Second DEMs Reveals Limitations in Terrain Morphology Representation. Remote Sens. 2024, 16, 3273. https://doi.org/10.3390/rs16173273 Guth, P.L.; Trevisani, S.; Grohmann, C.H.; Lindsay, J.B.; Reuter, H.I. Benchmarking Elevation Plus Land Surface Parameters Finds FathomDEM and Copernicus DEM Win as Best Global DEMs. Remote Sens. 2025, 17, 3919. https://doi.org/10.3390/rs17233919 Guth, P.L.; Van Niekerk, A.; Grohmann, C.H.; Muller, J.-P.; Hawker, L.; Florinsky, I.V.; Gesch, D.; Reuter, H.I.; Herrera-Cruz, V.; Riazanoff, S.; López-Vázquez, C.; Carabajal, C.C.; Albinet, C.; Strobl, P. Digital Elevation Models: Terminology and Definitions. Remote Sens. 2021, 13, 3581. https://doi.org/10.3390/rs13183581 Minár, J., Ian S. Evans, Marián Jenčo, 2020, A comprehensive system of definitions of land surface (topographic) curvatures, with implications for their application in geoscience modelling and prediction, Earth-Science Reviews, Volume 211, 103414, ISSN 0012-8252, https://doi.org/10.1016/j.earscirev.2020.103414 Strobl, P.A.; Bielski, C.; Guth, P.L.; Grohmann, C.H.; Muller, J.P.; López-Vázquez, C.; Gesch, D.B.; Amatulli, G.; Riazanoff, S.; Carabajal, C. The Digital Elevation Model Intercomparison eXperiment DEMIX, a community based approach at global DEM benchmarking. Int. Arch. Photogramm. Remote Sens. Spat. Inf. Sci. 2021, XLIII-B4-2021, 395–400. https://doi.org/10.5194/isprs-archives-XLIII-B4-2021-395-2021 Uhe, P., Lucas, C., Hawker, L., Brine, M., Wilkinson, H., Cooper, A., & Sampson, C. (2025). FathomDEM: an improved global terrain map using a hybrid vision transformer model. Environmental Research Letters, 20(3), 034002. https://doi.org/10.1088/1748-9326/ada972