Wrong orbit file ebing requested?

I am applying orbit files to products acquired on Dec 30, 2018. The orbit files snappy is trying to download (and fialing of course because they do not exist yet) are for Jan 2019. Why is that?

Product to replicate the error: S1A_IW_SLC__1SDV_20181230T221943_20181230T222010_025261_02CB25_6A3B

Here’s the first part of the error:

WARNING: org.esa.s1tbx.io.orbits.sentinel1.StepAuxdataScraper: Unable to connect to http://step.esa.int/auxdata/orbits/Sentinel-1/POEORB/S1A/2019/01/: HTTP error fetching URL                                       
WARNING: org.esa.s1tbx.sar.gpf.orbits.ApplyOrbitFileOp: No valid orbit file found for 30-DEC-2018 22:18:42.898437                                             
Orbit files may be downloaded from https://qc.sentinel1.eo.esa.int/                                                        
and placed in $HOME/.snap/auxdata/Orbits/Sentinel-1/POEORB/S1A/2018/12                                                                   
WARNING: org.esa.s1tbx.io.orbits.sentinel1.StepAuxdataScraper: Unable to connect to http://step.esa.int/auxdata/orbits/Sentinel-1/RESORB/S1A/2019/01/: HTTP error fetching URL                                       
INFO: org.esa.snap.engine_utilities.download.downloadablecontent.DownloadableContentImpl: http retrieving https://qc.sentinel1.eo.esa.int/aux_resorb/S1B_OPER_AUX_RESORB_OPOD_20181230T235844_V20181230T194634_201812
30T230404 

Why you said it is wrong?

Precise Orbit files are only available some days after acquisition (about 20 days), so while they are not available, Restituted Orbit files are downloaded by SNAP.
From the file name of the Restituded Orbit file downloaded, looking at its file name, only after the “V” which indicated validity time (S1B_OPER_AUX_RESORB_OPOD_20181230T235844_V20181230T194634_201812 30T230404) , fully covers the time indicated on the SLC file S1A_IW_SLC__1SDV_20181230T221943_20181230T222010_025261_02CB25_6A3B

However, if you only want to use Precise Orbit files (POEORB) you may need to wait still some days to get it ready.

Please anyone correct me if I am wrong.

1 Like

@mdelgado I was not exactly clear in my question.
I have been processing files and so far if the precise orbit files were not available a warning like the above was given and the restituted ones were being used. Thanks for the clarification particularly about theValidity. part.

However for this particular product on the date of posting the question the processing was failing. I did not show the error. After a about a minute of attempts to download the file a RuntimeError was being returned. Now it seems to work as expected using the restituted files.

Also, what I found weird is the first line in the warning where it checks Jan 2019:
WARNING: org.esa.s1tbx.io.orbits.sentinel1.StepAuxdataScraper: Unable to connect to http://step.esa.int/auxdata/orbits/Sentinel-1/POEORB/S1A/2019/01/: HTTP error fetching URL

Thank you for your reply.

From my point of view, the reason of that warning could probably be the following:
As the precise orbit file for the Sentinel-1A file acquired on 31 December 2018 should be available somewhere on January 2019, the program tries to get it from that folder (production date and not acquisition date), but obviously, the folder 2019/01 is still not existing as there is not Precise Orbit (POEORB) orbit yet .

I am not 100% sure as I am not from the developer team, I am just a SNAP user.
Please @marpet or @lveci correct me if I am wrong.