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 part of the spectrum centred around 715 nm.