Terrain Correction with SRTM-1sec

Hi – I’m a newbie to the S1 Toolbox. I have searched thoroughly in the threads about this – but haven’t found any solutions yet so am hoping a new thread can garner some help.

I am hoping to use the SRTM 1sec DEM for terrain correction but have hit a dead end. The auto-download SRTM 3-sec works great, but I’d really like to take advantage of the higher resolution 1-sec DEM. I cannot find details on how to use a “non-autodownloadable” DEM anywhere in the user guides or forums.

I have 1deg x 1deg geotiffs of the SRTM-1sec locally-- do relevant tiles need to be mosaicked into one file, and do we need to specify what directory these files somehow – or should I be selecting “External DEM” instead of SRTM1sec in the Terrain Correction module and point to where these DEM files sit?

I am using the most up-to-date version of the S1 Toolbox. Any info – or some direction – would be most appreciated!

but SRTM 1 sec is available as auto download.

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Ah, I see now that it’s available in the SNAP application. Thank you!

I have one more question about the previous used auto-downloaded SRTM 3 arc-second DEM. Is this SRTM plus which was released in 2013 (https://lpdaac.usgs.gov/about/news_archive/nasa_shuttle_radar_topography_mission_srtm_version_30_srtm_plus_product_release) ?

Kind regards

I’m trying to use the SRTM 1 sec, but they won’t autodownload.
Is there a way to force SNAP to do the autodownload?
Can I download the DEMs myself and put them into a folder somewhere that SNAP will look through?

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Use SRTM 1Sec HGT (Auto Download)


I’ve been trying that, but it won’t autodownload. Only a tiny portion of my frame gets processed, and I know that the SRTM 1 Sec covers more than what is processed because I’ve downloaded SRTM 1 Sec DEMs from EarthExplorer and they cover my entire area of interest.
I would tell SNAP to use those external DEMs, but so far it’s refused to use any external DEM I provide it and only processes that same tiny portion.

My experience is that one can download a SRTM tile from a repository (I use USGS) in GoeTIFF and select it for processing. This is located in the same dialog where one provides DEM, but selecting the last option and give the path to DEM file. And that’s all. For me it worked fine even with “local DEM”.