Normalized Difference Red Edge Index (NDRE)
What is Normalized Difference Red Edge Index (NDRE)?
The Normalized Difference Red Edge index is an index sensitive to chlorophyll content in leaves. It is better to use this index when plants are mature or ready to be harvested.
The standard scale for the NDRE index ranges from -1 to 1. The values can be interpreted as follows:
1 to 0.2 : bare soil or a developing crop;
0.2 to 0.6 : unhealthy plant or not yet mature;
0.6 to 1 : healthy, mature and maturing crops.
A low NDRE value may indicate damages, disease, pests, or lack of nutrients in crops.
How do you calculate NDRE?
It is calculated as:
NDRE = (NIR – RedEdge)/(NIR + RedEdge)
NDRE (Sentinel 2) = (B7 – B5)/(B7+ B5)
B7 and B5 correspond to reflectance in Sentinel 2 short-wave Visible and Near Infrared (VNIR) band 7 (783 nm) and RedEdge band 5 (705 nm), respectively.
References:
Application of NDRE, Rostenice farm