# Generated by scripts/sync_indices.py from Awesome Spectral Indices (MIT).
# DO NOT EDIT BY HAND. Edit overlays (_asi_*.yaml, _folia_*.yaml) and re-run.
# Spec: docs/spec/SPECTRAL_INDICES.md
slug: vari
name: Visible Atmospherically Resistant Index
short_name: VARI
formula: (G - R) / (G + R - B)
bands:
- G
- R
- B
domain: vegetation
theme: vegetation
concepts:
- fapar
- leaf-area-index
rank: 20
display:
  colormap: rdylgn
  range:
  - -0.5
  - 1.5
pedagogy:
  description: 'Visible Atmospherically Resistant Index (Gitelson 2002). An RGB-only

    vegetation index that uses blue to correct the red-green ratio for

    atmospheric scattering. The default greenness index for drones and

    RGB-only consumer sensors.

    '
  use_cases:
  - Drone and UAV vegetation monitoring (RGB cameras without NIR)
  - Historical aerial photography vegetation analysis where NIR is unavailable
  - Smartphone-based plant-health applications
  limitations:
  - Far less sensitive than NIR-based indices — saturates quickly and is noisier
  - Confused by yellow flowers and senescing vegetation
  - Atmospheric correction quality matters more than for NIR-based indices since visible bands carry more scatter
  interpretation:
    high: Visibly green, healthy canopy
    mid: Mixed cover
    low: Soil, bare ground
    negative: Water, deep shadow
  authoritative_sources:
  - label: Gitelson 2002
    url: http://dx.doi.org/10.1078/0176-1617-00887
  - label: NV5 ENVI — Visible Greenness
    url: https://www.nv5geospatialsoftware.com/docs/VisibleSpectrumIndices.html
  - label: Index Database · VARI
    url: https://www.indexdatabase.de/db/i-single.php?id=356
references:
- url: https://doi.org/10.1016/S0034-4257(01)00289-9
date_of_addition: '2021-04-07'
contributor: https://github.com/davemlz
platforms:
- Sentinel-2
- Landsat-OLI
- Landsat-TM
- Landsat-ETM+
- MODIS
- Planet-Fusion
source:
  authority: awesome-spectral-indices
  commit_sha: 7f28d3fe68af1287f7449faf0685659e73197212
  upstream_id: VARI
match_tags:
- atmospherically
- b
- g
- index
- r
- resistant
- vegetation
- visible
status: stable