Normalized Difference Red Edge (NDRE)

Description

The Normalized Difference Red Edge (NDRE) is a metric that can be used to analyze whether multi-spectral images contain healthy vegetation by measuring the amount of chlorophyll in plants. It has recently been applied to agriculture to image nitrogen levels.

It is calculated using near-infrared and red-edge spectral bands, which are both available through Sentinel-2.

NDRE = (NIR-RED_EDGE1) / (NIR+RED_EDGE1)

References

Barnes, E. M., Clarke, T. R., Richards, S. E., Colaizzi, P. D., Haberland, J., Kostrzewski, M., ... & Lascano, R. J. (2000). 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

Ku Wang, David R. Huggins, Haiying Tao (2019). Rapid mapping of winter wheat yield, protein, and nitrogen uptake using remote and proximal sensing, International Journal of Applied Earth Observation and Geoinformation,Volume 82, 2019, 101921, ISSN 1569-8432, https://doi.org/10.1016/j.jag.2019.101921.

Magney, Troy & Eitel, Jan & Vierling, Lee. (2017). Mapping wheat nitrogen uptake from RapidEye vegetation indices. Precision Agriculture. 18. 429-451. 10.1007/s11119-016-9463-8.