# 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: msavi
name: Modified Soil-Adjusted Vegetation Index
short_name: MSAVI
formula: 0.5 * (2.0 * N + 1 - (((2 * N + 1) ** 2) - 8 * (N - R)) ** 0.5)
bands:
- N
- R
domain: vegetation
theme: vegetation
concepts:
- fapar
- leaf-area-index
rank: 12
display:
  colormap: rdylgn
  range:
  - -0.2
  - 1.0
pedagogy:
  description: 'Modified Soil-Adjusted Vegetation Index (Qi 1994). Replaces SAVI''s

    fixed L term with a self-adjusting formulation that removes the need

    to tune L by hand. USGS ships an MSAVI product for Landsat as a

    drop-in arid-region NDVI alternative.

    '
  use_cases:
  - Arid and sparse-canopy vegetation monitoring without per-scene L tuning
  - Early-season crop emergence over bright soil where NDVI saturates the soil signal
  - Post-fire and post-disturbance regrowth tracking
  limitations:
  - Slightly more compute-heavy than SAVI due to the quadratic term
  - Still saturates at high LAI in the same regime as NDVI
  - Less established outside USGS / Landsat workflows than SAVI
  interpretation:
    high: Dense vegetation
    mid: Moderate canopy, mixed cover
    low: Sparse vegetation, soil-dominated
    negative: Water
  authoritative_sources:
  - label: Qi 1994
    url: https://doi.org/10.1016/0034-4257(94)90134-1
  - label: NV5 ENVI — Broadband Greenness
    url: https://www.nv5geospatialsoftware.com/docs/BroadbandGreenness.html
  - label: Index Database · MSAVI
    url: https://www.indexdatabase.de/db/i-single.php?id=44
references:
- url: https://doi.org/10.1016/0034-4257(94)90134-1
date_of_addition: '2021-05-13'
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: MSAVI
match_tags:
- adjusted
- index
- modified
- n
- r
- soil
- vegetation
status: stable