Viewing Vegetation Indices
The Analyze tab on each field’s detail page provides a unified view of all imagery layers — drone flights and satellite passes — on an interactive map.
Available indices
| Index | Full Name | Formula | What it measures |
|---|
| NDVI | Normalized Difference Vegetation Index | (NIR - Red) / (NIR + Red) | Overall vegetation health and density |
| NDRE | Normalized Difference Red Edge | (NIR - RedEdge) / (NIR + RedEdge) | Chlorophyll content, nitrogen stress detection |
| GNDVI | Green Normalized Difference Vegetation Index | (NIR - Green) / (NIR + Green) | Chlorophyll concentration, early stress |
| SAVI | Soil-Adjusted Vegetation Index | 1.5 × (NIR - Red) / (NIR + Red + 0.5) | Vegetation in sparse canopy (reduces soil influence) |
| EVI | Enhanced Vegetation Index | 2.5 × (NIR - Red) / (NIR + 6×Red - 7.5×Blue + 1) | Vegetation in dense canopy (reduces atmospheric influence) |
| CHM | Canopy Height Model | DSM - ground reference | Crop height and growth uniformity |
Using the Analyze tab
Layer selection
- Navigate to a field and open the Analyze tab
- The timeline at the bottom shows all available dates (drone flights and satellite passes)
- Select a date to load its layers
- Use the layer picker to switch between available indices
Colormaps
Vegetation indices render with scientifically standard colormaps:
- RdYlGn (Red-Yellow-Green) — default for most indices. Red = low/stressed, green = healthy
- Viridis — perceptually uniform, colorblind-friendly alternative
Toggle between colormaps using the colormap selector above the map.
Comparing layers
- Use the opacity slider to blend a vegetation index over the base map or orthomosaic
- Switch between drone and satellite layers for the same date range to compare resolution and coverage
- The timeline supports scrolling through historical data to track changes over the growing season
Interpreting NDVI values
| NDVI Range | Interpretation | Typical appearance |
|---|
| -1.0 to 0.0 | Water, bare soil, or non-vegetated | Dark red |
| 0.0 to 0.2 | Bare soil, residue, or very sparse vegetation | Red to orange |
| 0.2 to 0.4 | Sparse vegetation, early growth stage | Orange to yellow |
| 0.4 to 0.6 | Moderate vegetation density | Yellow to light green |
| 0.6 to 0.8 | Dense, healthy vegetation | Green |
| 0.8 to 1.0 | Very dense, peak vegetation | Dark green |
NDVI is a good general indicator, but NDRE is more sensitive to nitrogen stress in mid- to late-season crops. Use NDRE when scouting for nutrient deficiencies.
