'outputComplex' argument removed from Sentinel-1 terrain correction

Hi all,

It seems that in the last update of SNAP (v8.0.6), the argument outputComplex was removed from the terrain correction node xml for Sentinel-1. This change broke our production system.

It would be great if anyone could point me to the list of changes for each released version (major, minor and patch), so I can adjust our processing chains in advance.

I looked in github, jira, this forum, the esa sites, but I cannot find the information I’m looking for.

Kind regards,


Is there anybody from SkyWatch or SNAP in general who can comment on this? It would be great if release notes would be available, at the least for breaking changes.

@lveci, @jun_lu Can you please take a look?

The complex output option has been removed from terrain correction operator based on the suggestions of the ESA scientists. This is because the result is scientifically totally wrong. Sorry about the confusion

Thanks @oana_hogoiu for taking the initiative and @jun_lu for getting back to me so quickly.

Alright, I understand why you would remove the argument. Especially from a scientific point of view.

But what I don’t understand is why there is no documentation, or that the change is included in patch upgrade. As SNAP does not adhere to semantic versioning, this breaks operational systems (at least ours).

@jun_lu is it not possible to supply documentation about these changes? This would inform the community about the hard work that is put into SNAP, as well as preparing maintainers about possible upcoming breaking changes.


The descriptions about the changes are generally provided in the release notes. If we failed in doing that, it’s our fault. We will try to do better in future. Thanks for the suggestion!


Great to hear. Where are these release notes normally hosted? Then next time, I would know where to look!

I would like to raise that, regardless of ESA suggestions, we fully rely on this option for our processing and services generating substantial amounts of business based on S1.

@jun_lu can you share the location where the release notes are hosted? This would help a lot while searching for updates.

I think all the information can be found in the STEP JIRA board Dashboard - JIRA

@jun_lu I’m sorry, but as far as I can see with my current access, the Jira board only contains issues and no release notes. Also, when I search for the removed argument outputComplex, no relevant results pop up.

The GitHub of SNAP has a section about releases, but there is no information about the actual changes.

See https://github.com/senbox-org/snap-desktop/releases/tag/8.0.8

The Sentinel-1 toolbox tags contain even less information. See https://github.com/senbox-org/s1tbx/tags

Is there another place that might contain the information I’m looking for?

I agree with @egremmer. It would be great if there was an improvement in this regard and if we could get some proper release notes in the near future!

cc @johntruckenbrodt


I agree with all said before, I ran into this issue here and nobody answered back then.
Releasing the notes and stating what will be soon deprecated would be greatly appreciated :pray:

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@remi-braun I think that you ran into the same issue I described.

Is there anybody from the SNAP team or any of the companies involved who can comment on the release notes policy of SNAP?

Yes, this is what I meant, sorry for not being clear :sweat_smile:

No worries. It is good to see that I’m not the only one struggling with this issue. :slight_smile:

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Hello @egremmer,

Regarding the release notes policy of SNAP, the links of specific release notes are provided under the tabs of Help → About SNAP.
I agree with you that the link for S1TBX is not pointing to the right location (it shows only the changes of 8.0 major version), it should be similar with the one for S2TBX for example:
Release Notes

Optionally, a simple JIRA list extraction (plus additional details if needed) can be mentioned on github release notes, as for s2tbx for example:

@jun_lu please take this into consideration for the next s1tbx minor release, so that the users are informed about the changes.
Thank you :slight_smile:


Hi @oana_hogoiu,

The release notes of s2tbx contain the minor release changes, which is great! These are missing for s1tbx, see https://github.com/senbox-org/s1tbx/blob/8.x/ReleaseNotes.md

If the release notes of the minor changes of s1tbx could be published on github, that would be great.
Thank you for pointing to the location and addressing the issue, this is much appreciated!

Thanks @jun_lu for the fix.
From here [SITBX-905] - JIRA I can’t see in which release version of the s1tbx / snap the fix is included… Which one is it?

This method produces unusable incorrect geocoded phases so we would like to remove this option to prevent people from making mistakes.