Normalized Difference Red Edge Index Explained

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.^[1] It is similar to Normalized Difference Vegetation Index (NDVI) but uses the ratio of Near-Infrared and the edge of Red as follows:

NDRE = (( NIR - RE ))/(( NIR + RE ))

The red edge is the part of the spectrum centred around 715 nm.

External links

• Chlorophyll Absorption
• Spectral Reflectance Changes Associated with Autumn Senescence of Aesculus hippocastanum L. and Acer platanoides L. Leaves. Spectral Features and Relation to Chlorophyll Estimation
• https://www.tucson.ars.ag.gov/unit/publications/PDFfiles/1356.pdf
• Barnes, T.R., Clarke, S.E. Richards et. al. 2000. COINCIDENT DETECTION OF CROP WATER STRESS, NITROGEN STATUS AND CANOPY DENSITY USING GROUND-BASED MULTISPECTRAL DATA. Proceedings of the Fifth International Conference on Precision Agriculture

Notes and References

1. Barnes, E. M., Clarke, T. R., Richards, S. E., Colaizzi, P. D., Haberland, J., Kostrzewski, M., ... & Lascano, R. J. (2000, July). Coincident detection of crop water stress, nitrogen status and canopy density using ground based multispectral data. In Proceedings of the Fifth International Conference on Precision Agriculture, Bloomington, MN, USA (Vol. 1619). https://naldc.nal.usda.gov/download/4190/PDF