Vegetation index
Vegetation indices are one of the primary sources for observing and analyzing the earth's surface and especially vegetation . They use the red and near-infrared spectral range . Portable hand-held devices or aircraft or satellite-based multispectral sensors can be used for recording .
background
Vegetation indices make use of the strong increase in the degree of reflection of photosynthetic vegetation from the red (approx. 630–690 nm) to the near-infrared (approx. 750–900 nm) range. Chlorophyll , better: mesophyll, reflects about six times more strongly in the near infrared than in the visible spectrum.
Published indices
- VI ≈ DVI " D ifference V egetation I ndex" (NIR-Red) (Lillesand & Kiefer, 1987 (VI); Richardson & Everitt, 1992 (DVI)):
- RVI " R atio V egetation I ndex" (NIR / Red) (Jordan, 1969)
- WDVI
- NDVI " N ormalized D ifferenced V egetation I ndex"
- SAVI family " S oil A djusted V egetation I ndex"
- EVI " E nhanced V egetation I ndex"
- GRABS " GR eeness A bove B are S oil" (Hay et al., 1979)
- PVI " P erpendicular V egetation I ndex" (Richardson & Wiegand, 1977)
Other spectral indices
- Tasseled cap
- VARI (Visible Atmospherically Resistant Index) (Gittelson et al., 2002)
- NDBI (Normalized Difference Built-up Index) (Zha et al., 2003)
- AFRI (Aerosol Free Vegetation Index) (Karnieli et al., 2001)
- ARVI (Aerosol Resistant Vegetation Index)
- MSI (Moisture Stress Index) (Rock et al., 1986)
- LWCI (Leaf Water Content Index) (Hunt et al., 1987)
See also
Web links
- NASA Measuring Vegetation (NDVI & EVI) - Earth Observatory