Normalized Difference Red Edge Index

The normalized difference red edge index (NDRE) is a metric that can be used to analyse whether images obtained from multi-spectral image sensors contain healthy vegetation or not. It is similar to Normalized Difference Vegetation Index (NDVI) but uses the ratio of Near-Infrared and the edge of Red as follows:

${\mbox{NDRE}}={\frac {({\mbox{NIR}}-{\mbox{RE}})}{({\mbox{NIR}}+{\mbox{RE}})}}$

The red edge is the term used to describe the part of the spectrum centred around 715 nm.

External links

• Background on NDRE
• Chlorophyll Absorption