Red Edge Position derived with ESA's SNAP Sentinel-2 Toolbox

The S2REP results from the following equation: S2REP = 705 + 35*((Red+ VNIR3)/2-VNIR)/(VNIR2-VNIR) using Sentinel-2 Band 4 (Red), Band 5 (VNIR), Band 6 (VNIR2) and Band 7 (VNIR3).

S2REP is sensitive to both crop(chlorophyll content) N and growth status. Generally, the higher the S2REP value, the higher is the chlorophyll content.(Guyot, G., & Baret, F., 4th International Colloquium “Spectral signatures of objects in remote sensing”,p.279(1988))

The S2REP is called S2_S2REP in the Food Security TEP.