S1 ortho-rectification problems

Hi there,

Am using the Python API to download some S1 (ID: BANDS-S1-IW) and S2 (ID: BANDS-S2-L1C) images. Everything works fine with the S2 download but not the S1 download especially once ortho-rectification is turned on. The following error was reported initially:

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<![CDATA[

java.util.concurrent.ExecutionException: java.lang.RuntimeException: Could not load necessary digital elevation model for orthorectification! Please try again later or without orthorectification.

]]>

Is there a way of going around this problem? If not, is it possible to also download the original metadata (the .dim file from ESA) for each downloaded non-rectified image from the EOCloud in order to perform the ortho-rectification locally using SNAP?

Best regards,

Gideon

Hi Gideon,
can you send one of the requests failing with this code so that we can look into it?
Not sure if related, but I noticed that you are exceeding daily limit for trial account (10.000 requests per day, see rate limiting section)

To use SNAP you will have to download original data, orthorectify it and then make the data available within your python workflow.

Hi gmilcinski,

(1) Here is the request URL: https://services.sentinel-hub.com/ogc/wcs/f91929da-a8b5-MASKED?SERVICE=wcs&MAXCC=0.0&ShowLogo=False&Transparent=False&BBOX=53.5141933165647%2C7.25296442687846%2C53.6938555515629%2C7.43262666187667&FORMAT=image%2Ftiff%3Bdepth%3D32f&CRS=EPSG%3A4326&TIME=2018-12-29T05%3A41%3A35%2F2018-12-29T05%3A41%3A35&RESX=10m&RESY=10m&COVERAGE=BANDS-S1-IW&REQUEST=GetCoverage&VERSION=1.1.2

(2) When ortho-rectification is disabled in the configuration, am able to download the images. When I enable the ortho-rectification right after that and re-run the script, am able to down the images without any exception being thrown. The limiting factor here is the number of requests per day, which you say is 10000. Would an upgrade to individual commercial use be of help here?

(3) To use SNAP to ortho-rectify the clipped images downloaded from the EO Browser, I will need to metadata info per ach image. Is there a way of getting this as well from the EO Browser per each download?

Best regards,

Gideon

As this request does work for me (and reading your lines, for you as well), it seems that the error might have indeed been on the rate limiting.

If you subscribe for individual commercial, the limit is indeed quite a bit increased, to 100.000 per month.

Okay, thanks for the reply. Really appreciated!

Hi once again, so we got a commercial license now and am still having difficulties with the download of the ortho-rectified S1 images. I have been running the script since yesterday. The script is still running but there is NO download or I have not received an error message from the API. Can you please check what is happening? Thanks a lot.

Hi, has the issue Gideon reports here been resolved?
I am experiencing something similar with this request:
http://services.sentinel-hub.com/ogc/fis/3c8140c3-d6cc-4cd6-9b8c-MASKED?SERVICE=fis&MAXCC=100.0&EvalScript=cmV0dXJuIFtWVl07&CRS=EPSG%3A32632&LAYER=BANDS-S1-IW&RESOLUTION=10.0m&TIME=2018-07-01T00%3A00%3A00%2F2018-07-20T23%3A59%3A59&BBOX=509815.0%2C4673834.0%2C509817.0%2C4673836.0 (part of instance-id is masked)
When orthorectify is turned off, it works fine; when turned orthoreectify is on, it fails, throwing this exception:

<![CDATA[
java.util.concurrent.ExecutionException: java.lang.IndexOutOfBoundsException
]]>

…after further investigation I found a workaround for the issue: my geometry is quite small (below 10x10 m). If I inflate the geometry a bit (greater ~10x10 m) the above exception does not occur.
Best,
Martin

Orthorectification was not really designed for such a small areas… Thanks for identifying an issue and even finding a work-around!

Same issue here: https://services.sentinel-hub.com/ogc/wcs/96d73c6c-7528-4139-a684-MASKED?SERVICE=wcs&BBOX=60.262283280642%2C10.9757921472731%2C60.4329010986405%2C11.1889476164122&FORMAT=image%2Ftiff%3Bdepth%3D32f&CRS=EPSG%3A4326&TIME=2018-01-02T05%3A46%3A43%2F2018-01-02T05%3A46%3A43&RESX=10m&RESY=10m&COVERAGE=VV&REQUEST=GetCoverage&VERSION=1.1.2

[ java.util.concurrent.ExecutionException: java.lang.RuntimeException: Could not load necessary digital elevation model for orthorectification! Please try again later or without orthorectification. ]

Any idea? BBOX is rather big so that should be OK. Token seems OK, credits also.

Hi @Tech, it’s not exactly the same issue, but there certainly is an issue.
We are looking into it.

Hi @Tech,

we found an issue and pushed the fix to the production so there should hopefully not be any more of these types of errors (orthorectification is hard and DEM is not as homogenous as one would hope for, so there might be some other border cases…)

Thanks for raising this.
Best,
Grega

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