S1-GRD 2017 over the sea

Dear all,
i’m tryng to apply this workflow

to the following S1 product: S1A_IW_GRDH_1SDV_20170701T045534_20170701T045559_017273_01CD3D_BF09 (it is acquired over the sea in the Mediterranean area).

The processing does not work properly (it took hours and the output is more than 6 GB!)

I performed the workflow also step by step and I figured out that the problem is with TC.
Does anyone know if the S1 images acquired on 2017 over the sea have problem with TC operator?
I have tried to processing S1 products acquired over the sea in the Mediterranean area on 2019 and there are no problems.

there is an option “mask out areas without elevation” which can cause problems during the terrain correction (e.g. produce an empty output). Have you checked if it is set correctly?

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Dear Mr. @ABraun, thanks a lot for your answer.
Yes, I do not check “mask out areas without elevation”…also because I’m interested in the sea. It is weird the fact that I do not have problems in processing the images of the last years (2019-20) but I have problems with the images of 2017! It takes too long time!
I have tried to replace the TC with Ellipsoid-Correction, but also EC took more than 30 min (performed as single processing, I mean not integrating it on the graph) and the output is more than 3 GB!

have you maybe changed the output resolution?

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No, I keep the default 10m resolution

very strange. Sometimes it helps to close SNAP to fully clear the cache. But you have probably tested this already.

So even if you process all steps separetely, the Terrain Correction takes the longest?
Please try to terrain correct the speckle filtered output (without dB scale). You can perform the conversion to dB at the very end as well (in case this speeds up the TC).

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I do not use to clear the cache. Could you please tell me how to do it?

Close SNAP and open it again :slight_smile:

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Very easy :sweat_smile: thank you very much!