How is L2A data generated for AWS?

Sentinel@AWS
1

Hi,

I downloaded S2B_MSIL2A_20201115T185649_N0214_R113_T11TLM_20201115T211121 from s3://sentinel-s2-l2a/ using the “sentinelhub” Python library. I wanted to compare the B04 image against the L2A B04 image I have created locally using Sen2Cor 2.5 (with default configuration). The results seem to be different and the locally generated image seems to be a better image visually that that retrieved from AWS.

While I double check that I haven’t done something stupid my end It would be useful know what process is used to generate the L2A data in AWS.

There is some discussion here (https://forum.step.esa.int/t/check-which-version-of-sen2cor-was-used/18550) about using the MTD file to work out which version of Sen2Cor was used but I don’t see an MTD file under the product or tile key in AWS. I do see one for the locally generated data.

The original announce (https://medium.com/sentinel-hub/sentinel-2-l2a-products-available-on-sentinel-hub-beab58903285) talks about using Sen2Cor in some areas but also talks about using “a run-time optimized statistical atmospheric correction”.

How do I tell what has been done to produce each L2A product?

Thanks in advance

2

All L2A data on AWS after December 2018 are processed by ESA and replicated to AWS. ESA is using Sen2Cor 2.8. I suggest you contact them for the details.

3

Ok, thanks for the response

4

Hi,
I have a problem to run Sen2Cor on Sentinel-2 L1C images from AWS-sentinelhub.
There is no MTD_MSIL1C.xml file!! That is the data I have.

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5

Not sure if you are aware, but there is full archive of Sentinel-2 L2A data available on AWS, globally since 1.1.2017.
arn:aws:s3:::sentinel-s2-l2a

For the mentioned file, see this thread:
https://shforum.sinergise.com/t/missing-files-from-sentinel-aws-product/3913

Best,
Grega