DEMIX Difference Distribution Histograms

DEMIX seeks to rank 6 global 1 arc sec DEMs (COPDEM, FABDEM, ALOS, NASADEM, SRTM, and ASTER) [1].  It uses the difference between the global DEM and a comparable reference DEM aggregated from 1-5 m lidar-derived UTM DEMs.  For each DEM it calculates 5 criteria for describing the elevation, slope, and roughness distributions.  Evaluations for each criterion are included in the DEMIX GIS database [2].  These distributions have been used in several presentations [1,5,6].

This data set includes:

A CSV format database table listing the 236 tiles used by DEMIX {1], summary statistics for the reference DTM version of the tile, and a link to the PNG graphic with the 3 histograms (if the tile does not have a DSM), and 6 histograms (if the tile has both DSM and DTM).  The MICRODEM GIS program [3,4] can display this database, and display the histogram for selected tiles.  Filtering of the GIS database allows display of just the histograms for tiles with selected characteristics.

DBF version of the same database

236 PNG files with the difference distributions.  The histograms cover only the central part of the distributions, which should show a mode close to 0 if the DEM is unbiased.  If the histogram does not show a mode for a DEM, it's a clear indication that DEM is not very good in that tile.

References:

Bielski, C.; López-Vázquez, C.; Guth. P.L.; Grohmann, C.H. and the TMSG DEMIX Working Group, 2023. DEMIX Wine Contest Method Ranks ALOS AW3D30, COPDEM, and FABDEM as Top 1” Global DEMs: https://arxiv.org/pdf/2302.08425.pdf.  A revised version of this preprint will be posted soon.

Guth, P. L., 2023. DEMIX GIS Database Version 2 (2.0) [Data set]. Zenodo. https://doi.org/10.5281/zenodo.8062008 .

Guth, P.L., 2023, git_microdem: https://github.com/prof-pguth/git_microdem , open source software.

Guth, P.L., 2023, MICRODEM: Open-source GIS with a focus on Geomorphometry:  https://microdem.org/ , download for Windows-64 installation program and CHM help file.

Guth, P.L., Grohmann, C.H., & Trevisani, S., 2023,  Geomorphometric and Geospatial Patterns in Differences Between ALOS and COPDEM: Geomorphometry2023. https://doi.org/10.5281/zenodo.8057703

Coming soon