Period: 2016 – present

Sensor: Sentinel 2 MSI

Frequency: 5 days at equator

Resolutions: 20m

Extent: Global

The product algorithm can be accessed here.

Algorithm description: Three indices sensitive to vegetation water can be calculated using Sentinel 2 data.

Moisture Stress Index (MSI):

$MSI\quad =\quad \frac { { R }_{ Band11 } }{ { R }_{ Band8 } }$

Normalized Difference Infrared Index (NDII)

$NDII\quad =\quad \frac { { { R }_{ Band8 }\quad -\quad R }_{ Band11 } }{ { { R }_{ Band8 }\quad +\quad R }_{ Band11 } }$

Note that NDII is also referred as NDWI (Gao et al 1996), however in case of Sentinel 2 formulations, NDWI is calculated using band 3 and 8. This NDWI is more sensitive to changes in the water bodies (McFetters 1996), whereas NDII is more sensitive to vegetation water thickness.

Accuracy: Product is new and has not been validated.

Reference:

Gao, B. NDWI—A normalized difference water index for remote sensing of vegetation liquid water from space. Remote Sens. Environ. 58, 257–266 (1996).

McFEETERS, S. K. The use of the Normalized Difference Water Index (NDWI) in the delineation of open water features. Int. J. Remote Sens. 17, 1425–1432 (1996).