DEMIX GIS Database Version 4.1

DEMIX Database version 4.1

Data created for publication:

•  Guth, P.L.; Trevisani, S.; Grohmann, C.H.; Lindsay, J.B. Reply to Ho et al. Comment on “Guth et al. Benchmarking Elevation Plus Land Surface Parameters Finds FathomDEM and Copernicus DEM Win as Best Global DEMs. Remote Sens. 2025, 17, 3919”. Remote Sens. 2026, 18, 2399. https://doi.org/10.3390/rs18142399

This database supports the work of the Digital Elevation Model Intercomparison eXperiment (DEMIX) working group (Strobl and others, 2021) and particularly the previous comparison efforts (Guth and others, 2021; Bielski and others, 2024; Guth and others, 2024; Guth and others, 2025).

This version only includes 626 new test tiles, and may have biases because the tiles were selected to add diversity to the version 4 database.  It should be used in conjunction with the full version 4 (Guth, 2025).

Database changes:

• Tiles names are taken from the source HRDEMs.  This avoids required separate code for every national mapping agency (and some, like the USGS, currently have at least 3 naming standards for their tiles).  It also includes the survey date for some countries (currently only the USA).
• Added three additional fields to the tile characteristics: Koppen climate classification (Rube and Kottek, 2010), Biome Name (Copernicus Land Monitoring Service, 2017) and average canopy height from the laser radar altimeters (NASA, 2026).
• Three additional criteria in the mixed FUV database: KNCC, KPS, and MAD2.
• One new LSP in the difference distribution data: TAN
• Add collections to group test tiles in terms of when they were added to the analysis, and the reason.  This database includes these new collections with new test tiles:

o   Urban areas (107 tiles): these are problematic with 10×10 km tiles, since urban areas typically