Gridded Normalized Difference Vegetation Index of SLSTR/S3A

In the ‘ ‘(Level 2 product of SLSTR ), was the NDVI data calculated using surface reflectance of TOA reflectance?

Thanks a lot in advance.

On the page I couldn’t quickly find an answer.
I would suggest that you write a mail to
It is the official contact point for such questions.
If you get an answer, please let us know.