Comparison of different DEM

Hi,

I want to compare a self made S1 DEM with a 90m DEM from TandemX (eg. Differential maps, stadard deviation…). Are there any tools for that in SNAP (for coregistration, resampling…)?

when you geocode your S1 DEM with the Range Doppler Terrain Correction module, simply use the TanDEM-X model as external DEM (make sure you project it into WGS84) and check “Elevation” as additional output. The final product consists of elevation_VV (this is your S1 DEM) and elevation (your TanDEM-X elevation). You can then perform a raster differencing to see how similar both rasters are.

4 Likes

Hi
I made three different DEMs for three different years for a glacier.
This is what I did:

  1. I did subset and tried to give same geo-coordinate in ‘specify product subset’ but anyway, in the last, I had few pixels differences for three TanDEM-X data.

Info for the first subset of TanDEM-X data (1):
8823×5815

Info for the second subset ofTanDEM-X data (2):
8798×5403

Info for the third subset of TanDEM-X data (3):
8778×5807

  1. Then, I made interferograms, multilooking (2 by 2), Goldstein filtering (5), unwrapping, phase-to-elevation (Copernucus 30m).
    In this step, I checked pixel info and results were like this:
    The first DEM: 4411 × 2907
    The second DEM: 4399 ×2707
    The third DEM:4389 ×2903
  2. In this step, I applied terrain correction and I used copernicus DEM for terrain correction. I also give pixel spacing 6m to any of producs.
  3. In this step, I did stacking by using coregistration—stack tools—creat stack----

Then I overlaid DEMs on each others but their locations are different as you can see in below images.

I do not know what should I do to have same pixels and geo location…
and why the stacking did not work for them…