SNAP sentinel-2 IDEPIX Cloud masking error

[davisalukka]

Hi all,

I am currently facing some issues with SNAP’s IDEPIX module for cloudmasking for sentinel-2 imagery.

Following are the steps I have followed:

Step 1: I downloaded sentinel-2 imgary via product library.

Step 2: Opened in SNAP

Step 3: Resampled imagery to Output resolution of 60

Step 4: Setup IDEPix Params

Issue: SNAP freezes at this step, I see a small window open up, but no dialog box or confirmation message. It doesn’t seem to be a matter of waiting to finish processing as i have waited several hours (6+) and yet the program does not seem to unfreeze.

I’d appreciate any possible help on this issue.

[marpet]

This is a known issue in the S2 Idepix. Please have a look at this post:

Issue with IdePix cloud shadow detection

That IdePix hangs if cloud shadow detection is enabled is a known issue (IdePix MSI hangs if Cloud Shadow computation is enabled · Issue #25) and has been fixed already on the development branch. The fix will be included in the next update of IdePix. But I can’t give you a specific schedule right now.

[marpet]

An update has just been released. It should not hang anymore:

Release S2MSI v8.0.1 update · bcdev/snap-idepix

[bridgefisher]

The application is still hanging for me when trying to run IdePix on S2 imagery (following resampling to 60 m).
–> Optical - Preprocessing - Masking - IdePix (Clouds, Land, Water) - Sentinel-2 MSI

I’ve tried running on smaller file subsets, with just the default options turned on, and it appears to get further in the process based on the status bar, but still doesn’t complete. When I try to run a full scene with all options turned on the processing dialog appears for a few seconds, vanishes, and then again the program hangs. I’ve left SNAP running for 12+ hours just to make sure I’m giving it adequate time.

[blohmwe]

Hi There,
I’ve got the same problem on SNAP 8.

[gsjlogie]

Hi, this is also a problem for me as of this writing. I have updated SNAP and IDEPIX.

[abruescas]

I just tried it with a whole scene -previous resampling to 60m- and seems to be working fine. Try without saving in .dim, just open the result in SNAP, it usually takes less time (you can save it later).

[blohmwe]

OK, processing works but saving the .dim is very slow.

Next step is processing the C2RCC. The problem is the same. Processing will stop because the pixel_classif_flags.img in the …idepix.data is missing.

Then I tried to proccess the C2RCC with a well proccessed Idepix (from SNAP 7) without saving the dim. That works but saving the C2RCC-dim will last saving at 7% while saving the ‘rtoa_B8’. Storing is also very slow.

It seems that there are problems storing the dim-files.

[abruescas]

You could try to do the whole process with a gpt command line instead of the GUI. It is faster and you can do batch processing on several scenes. Let me know if you need help here.

[davisalukka]

Thanks for your response. Can you please provide instructions on how to go about doing this on the command line? Thank you.

[abruescas]

Here are some instructions to start with. If you have more specific questions after a firts try, I am happy to help.
Bulk Processing with GPT - SNAP Wiki