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Hi.

i downloaded Copernicus 30m DEM data from AWS and compared it to SRTM, Lidar and Tandem-x products, all resampled to 10m resolution. It seems as if the height information is shifted compared to these other datasets.


For better visibility, i’ve taken the difference of the DEMs in the following:


The difference for example between TDM and SRTM (right image) in most lightly vegetated areas is very small, and does not show much of a regular pattern.



Both have the same colorscale, the left shows a clear wavepattern, suggesting positional shift of the Copernicus DEM against the other three DEMs.


Is this an error on my side? Thanks for reading!


Cheers

We are using Copernicus DEM quite a bit and we have not noticed an error so far, neither did anyone else.

I can’t tell much from the image you posted.


Perhaps you can cross-check the data you have with the data coming from our services, to make sure that your processing does not impact the data:

docs.sentinel-hub.com
4360130503a7e9abd125dc1335988ba0465771bf.png


Digital Elevation Model (DEM) Data



A digital elevation model (DEM) is a 3D representation of terrain's surface you can use to analyze heights in your AOI.








Thanks for the response!

I redownloaded and compared the raw and unresampled data, no shift visible between SRTM and Copernicus DEM, so the error must be on my side.


Just a clarification for the upper image: the meadow and agricultural areas shown should have not much of a change over the years. The difference therefore should be mostly random. In the right image, this is mostly the case with uniform grey values. The left image has bright and darker sides, following the relief. So one if the data inputs is shifted to north-west compared to the other.


Cheers!


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