Normalized Difference Red-Edge Index (NDRE)

The Normalized Difference Red-Edge Index (NDRE) can be calculated only if the red-edge band is available. The red-edge band is very sensitive to medium to high levels of chlorophyll content.

 

Hence, red-edge is a good indicator of crop health in the mid to late stage crops where the chlorophyll concentration is relatively higher. Also, the NDRE could be used to map the within-field variability of foliar nitrogen to understand the fertilizer requirements of the crops.

 

                                                           

 

The red-edge band is capable of penetrating the leaf better than the red band that is absorbed by the chlorophyll in the first few layers.