Normalized Difference Vegetation Index (NDVI)
"The normalized difference vegetation index (NDVI) is a standardized index allowing you to generate an image displaying greenness, also known as relative biomass. This index takes advantage of the contrast of characteristics between two bands from a multispectral raster dataset—the chlorophyll pigment absorption in the red band and the high reflectivity of plant material in the near-infrared (NIR) band.
The documented and default NDVI equation is as follows:
NDVI = (NIR - Red) / (NIR + Red)
NIR = pixel values from the near-infrared band
Red = pixel values from the red band
This index outputs values between -1.0 and 1.0." (ESRI, 2018)