authority: folia
slug: ndvi
name: Normalized Difference Vegetation Index
domain: vegetation
subdomain: indices
authority_id: folia:ndvi
external_ids:
  spyndex: NDVI
canonical_units: dimensionless
canonical_range: [-1, 1]
description: |
  Normalized Difference Vegetation Index = (NIR - Red) / (NIR + Red).
  Foundational vegetation index; positive values for healthy vegetation,
  near zero for bare soil, negative for water. Workhorse metric for
  agriculture, phenology, drought, deforestation, and change detection.
theme: vegetation
formula: "(N - R) / (N + R)"
status: documented
sources:
  - https://github.com/awesome-spectral-indices/awesome-spectral-indices