The modified soil-adjusted vegetation index (MSAVI) is a soil adjustment factor added to NDVI to correct for soil noise effects such as soil colour and moisture when the vegetative cover is low. MSAVI accounts for the bare soil, whereas NDVI, under the same conditions, reads as lack of vegetation due to the sparseness of the vegetation or due to a lack of chlorophyll.

Read more about NDVI, NDRE and MSAVI: