The MODIS Enhanced Vegetation Index (EVI) is also used as a measure of the greenness and health of vegetation. It is calculated in a similar fashion as NDVI but it corrects for distortions caused by ground cover beneath the canopy vegetation and distortions in reflected light caused by particles in the air by using the blue band to remove residual atmosphere contamination caused by smoke and sub-pixel thin cirrus clouds. The EVI is more effective in areas with large amounts of chlorophyll such as rainforests. The index values range from -0.2 to 1 where higher values (0.3 to 1) indicate areas covered by green, leafy vegetation and lower values (0 to 0.3) indicate areas where there is little or no vegetation.

The MODIS rolling 8-day EVI layer is available as a near real-time, rolling 8-day product (MOD13Q4N) from from the Terra satellite. It is created from a rolling 8-day land surface reflectance product, MOD09Q1N. The sensor resolution is 250 m, imagery resolution is 250 m, and the temporal resolution is an 8-day product which is updated daily.

References: NASA Earth Observatory - Measuring Vegetation; NASA Earthdata - New Vegetation Indices and Surface Reflectance Products Available from LANCE; NASA NEO - Vegetation Index