Normalized Difference Vegetation Index (NDVI)

The Normalized Difference Vegetation Index (NDVI) is one of the most commonly used method for monitoring the percentage of green cover in an area. Since it is a ratio, this index is invariant to the difference in illumination conditions, slope, seasons, etc. and thus suitable for crop monitoring throughout the growth season. It is calculated by taking a ratio between the difference of reflectance from NIR and Red bands and the sum of reflectance from NIR and Red bands.