# 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: kndvi
name: Kernel Normalized Difference Vegetation Index
short_name: kNDVI
formula: (kNN - kNR)/(kNN + kNR)
bands:
- kNN
- kNR
domain: kernel
theme: vegetation
concepts:
- fapar
- leaf-area-index
rank: 21
display:
  colormap: rdylgn
  range:
  - 0.0
  - 1.0
pedagogy:
  description: 'Kernel Normalized Difference Vegetation Index (Camps-Valls 2021).

    A nonlinear-kernel reformulation of NDVI that maps NIR and red into

    a higher-dimensional feature space where the difference saturates more

    gracefully. Strongest correlation with gross primary productivity (GPP)

    among standard vegetation indices.

    '
  use_cases:
  - Gross primary productivity and carbon-flux modelling at moderate resolution
  - Dense-canopy phenology and biomass tracking where NDVI saturates
  - Long-term archive reprocessing where higher-information greenness is needed
  limitations:
  - Kernel-bandwidth parameter sigma must be tuned per scene or land-cover regime
  - Slightly more compute than NDVI due to the kernel mapping
  - Not yet a default in operational products; tooling and conventions are still emerging
  interpretation:
    high: Dense, highly productive canopy
    mid: Moderate canopy
    low: Sparse vegetation
    negative: Water, bare surfaces
  authoritative_sources:
  - label: Camps-Valls 2021 (Sci Adv)
    url: https://doi.org/10.1126/sciadv.abc7447
  - label: NV5 ENVI — Broadband Greenness
    url: https://www.nv5geospatialsoftware.com/docs/BroadbandGreenness.html
  - label: Index Database · kNDVI
    url: https://www.indexdatabase.de/db/i-single.php
references:
- url: https://doi.org/10.1126/sciadv.abc7447
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: kNDVI
match_tags:
- difference
- index
- kernel
- knn
- knr
- normalized
- vegetation
status: stable