External DEM

We try to use an external DEM but without success. We chose different formats trying the same format than SNAP using file .hgt in input.Nothing work except those downloaded by snap. It is worth mentioning that for all people working on active volcanoes it is necessary to compute interferograms using high resolution DEM. So my question is following Is it possible to use SNAP with an external DEm and in the affirmative what is the format expected by the program ?

what comes to my mind is that the DEMs must be in WGS84 and not a local projection.

Do you select them manually in the corresponding module or do you place them in the AUX folder?

I haven’t tested hgt-files but I would rather use GeoTIFFs as an input.

Dear ABraun,
Thank you for your reply. The DEM is in WGS84 and not in UTM or local projection. I would use a DEM with 10 m posting. I tried different format ENVI, geotiff. I selected it manually. As I did not succed to compute the interferogram, I load the SRTM 1Sec grid (hgt) that I tranformed in geotiff file using SNAP. When I use it as external DEM the resulting phase contribution is flat with a constant value of 1 !
it seems that the elevation is not correctly read but I don’t know the reason.
Thank you for helping me

Where is the .snap/auxdata/r equivalent in a Windows installation? I can’t seem to find it even viewing hidden files and folders?


your user folder has a hidden .\snap directory, you need to enable hidden files to see it.