What's the difference between NDVI and EVI imagery?

What's the difference between NDVI and EVI imagery?

Normalized Difference Vegetation Index (NDVI) is a popular way of using visible and near-infrared data to come up with a score that represents the health and biomass quantity of vegetation. This is how we can show you a map with red "bad" parts of the field and green "good" parts of the field, instead of just a picture of what it looks like with your eyes.

Enhanced Vegitation Index (EVI) was created to have better consistency than NDVI, by accounting for several other factors that can cause NDVI values to come out different depending on the time of day and atmospheric conditions when the image was captured. We have also found that EVI is able to show stress patterns in the crop that don't show up in the NDVI image, or are much harder to see.