Sentinel2 artefacts


I wanted to download single bands from the collection Sentinel2_L2A, so I used as output format the netCDF one. But I was quite surprised of the result :

(red,green,blue,nir and then RGB)
Design sans titre

I tried the GTIFF format but get the sames results…

job id (netCDF) : vito-j-fbaab6ecf7304bf2be91ee7a59b57cdd

job id (GTIFF) : vito-j-03a9ccfe967041448aed7cf09a45db53

I tried the same process graph with a synchronous download but get the same results too.
I also tried another temporal extent but I still get some of these white pixels / artefacts. (see below)

The thing that I don t understand is that in the openEO preview tool, everything looks fine, so something happens during the download I guess…

OpenEO preview of the job id (GTIFF) : vito-j-03a9ccfe967041448aed7cf09a45db53:

Thanks for your answer !


Hi Selim,
thanks, it seems that the data was fetched from sentinelhub, and we used data type uint16.
The derived from links indicate that Sentinel-2 L2A with processing baseline 4.0 was used:

So my guess is that these white nodata pixels are actually negative values. The preview probably just has different visualization.
I logged an issue, please let us know if you have more info, or if we should prioritize a fix. (It seems a relatively low impact issue, assuming SENTINEL2_L2A is mostly suitable for land applications.)

Hi Selim,

As Jeroen said, on newer Sentinel2 some pixels can become negative.
When requesting those with SENTINEL2_L2A_SENTINELHUB, they get discarded as noData (probably showing as the bright background of your tiff viewer)

You can also do the same request with with SENTINEL2_L2A, negative pixels will be visible, and only pixels that have exactly reflectance ‘0’ will become noData.

The difference is visible in the following picture:

That reflectance 0 gets interpreted as nodata looks like a small bug to me at the moment. I updated the github issue.