WARNING: org.esa.snap.core.dataop.dem.ElevationFile: http error

development python
1

Hi,

I’m using subprocess.run([GPT_PATH, str(xml_file_name)]) to run xml graphs to preprocess Sentinel-1 data. I’m getting the error

WARNING: org.esa.snap.core.dataop.dem.ElevationFile: http error:http://step.esa.int/auxdata/dem/SRTMGL1/S18E121.SRTMGL1.hgt.zip on http://step.esa.int/auxdata/dem/SRTMGL1

It seems similar to this question but in the link http://step.esa.int/auxdata/dem/SRTMGL1/S18E121.SRTMGL1.hgt.zip produces 404 not found. Going to the link http://step.esa.int/auxdata/dem/SRTMGL1/ reveals that the S18E121 file isn’t there. The list skips from S18E119 to S18E122.

I’ve just run the same xml graphs manually in SNAP and the terrain correction module works fine. Any ideas what happening here?

Edit: It seems as if the terrain correction is actually being correctly applied. Maybe this is nothing to worry about?

2

If you confirmed it works with the warning the same as it does in the GUI, than you’re correct there’s nothing to worry about. I suspect there are backups that happen when a link fails that are hidden in the GUI but in code the Warning messages are shown.

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3

the same thing happened to me , this warning can appear when one of the requested SRTM tiles covers only sea, so that tile is not available in the SRTM archive.
WKT for your S18E121 –> POLYGON((121 -18,122 -18,122 -17,121 -17,121 -18))

see that it lies in the sea

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