I have started experimenting creating basic 3D elevation models in QGIS recently. It turned out for me that there are several free sources of DEMs, like USGS's EarthExplorer, CGIAR-CSI's Digital Elevation Database and also EU-DEM from the Copernicus Program.
As far as I could have found out, the best resolutions of these data are the following:
- SRTM elevation data from USGS's EarthExplorer site is available in 30 meter resolution - 1 arc second
- SRTM elevation data from CGIAR-CSI site is available in 90 meter resolution - 3 arc second
- SRTM elevation data from EU-DEM site is available in 25 meter resolution - 1 arc second
Is there any significant difference between these data sources and their accuracy? Especially between USGS EarthExplorer and EU-DEM? I would like to use data of Europe and european cities so when I say difference, I mean the resolution, accuracy or quality and not the geographic coverage.
(Basically, I would like to find out which source is the best choice for a 3D model and I cannot see the difference between the American and the European DEM)