Vegetation Index · Red-edge based

NDVI_RE – Red-Edge Normalized Difference Vegetation Index

NDVI_RE replaces the traditional Red band with a Red-Edge band to increase sensitivity to chlorophyll, vegetation stress, and subtle canopy changes—especially with Sentinel-2 imagery.

1. Scientific Definition

NDVI_RE (Red-Edge NDVI) is a modified vegetation index that enhances detection of chlorophyll content and early plant stress by using the red-edge region instead of the red band.

Formula

NDVI_RE = (NIR − RedEdge) / (NIR + RedEdge) Range: −1 → +1

  • NIR: Near-InfraRed reflectance
  • RedEdge: Red-edge reflectance (~705–740 nm)

Typical Interpretation

NDVI_REInterpretation
< 0Water, shadows, non-vegetated surfaces
0 – 0.2Very sparse / stressed vegetation
0.2 – 0.5Moderate vegetation health
> 0.5Healthy dense vegetation / high chlorophyll

Applications

  • Precision agriculture
  • Early stress detection
  • Chlorophyll estimation
  • Forest & crop monitoring

2. Required Bands

Sentinel-2

  • Red-edge: B5 (~705 nm) or B6 (~740 nm)
  • NIR: B8 (~842 nm)

Good Practice

  • Use surface reflectance (S2_SR)
  • Mask clouds & shadows
  • Compare images with same phenological stage

Suggested Palette

[ "#440154", "#3b528b", "#21908c", "#5dc963", "#fde725" ]

3. Google Earth Engine Code – NDVI_RE


// NDVI_RE using Sentinel-2
// Formula: (NIR - RedEdge) / (NIR + RedEdge)

// AOI
var roi = geometry;
Map.centerObject(roi, 11);

// Load Sentinel-2 SR
var s2 = ee.ImageCollection("COPERNICUS/S2_SR")
  .filterBounds(roi)
  .filterDate("2023-01-01", "2023-12-31")
  .filter(ee.Filter.lt("CLOUDY_PIXEL_PERCENTAGE", 20))
  .select(["B5", "B8"]); // B5 = Red-Edge, B8 = NIR

var img = s2.median().clip(roi);

// Compute NDVI_RE
var ndvi_re = img.expression(
  "(NIR - RE) / (NIR + RE)",
  {
    "NIR": img.select("B8"),
    "RE": img.select("B5")
  }
).rename("NDVI_RE");

// Visualization
var vis = {
  min: -1,
  max: 1,
  palette: ["#440154", "#3b528b", "#21908c", "#5dc963", "#fde725"]
};

Map.addLayer(ndvi_re, vis, "NDVI_RE");

// Export
Export.image.toDrive({
  image: ndvi_re,
  description: "NDVI_RE_Export",
  fileNamePrefix: "NDVI_RE",
  region: roi,
  scale: 10,
  crs: "EPSG:4326",
  maxPixels: 1e13
});