Hi,

I assume you are referring to the scripts that are used in the FIS for cloud detection. Those scripts all based on Braaten-Cohen-Yang cloud detector.

You can find more info in it in our custom-script repository where we also link the original research article.

Sentinel-Hub custom scripts

Braaten-Cohen-Yang cloud detector

A repository of custom scripts that can be used with Sentinel-Hub services.

As you will see there the NDGR was in the original paper used as a Normalized Difference index of the Green and Red band and therefore the acronym.

Best

Thank you. In script I saw, the position of the G and D were swapped.

Small addition: Depending on which collection the script is used, different band numbers might correspond to the Green or Red band. You can info on which band corresponds to which wavelength in our documentation (e.g. here for Sentinel 2 L2A).