Soil-Adjusted Vegetation Index

The term soil-adjusted vegetation index ( BBVI ) is a vegetation index . In English, he will SAVI abbreviated , what s oil a djusted v egetation i ndex is. Like other vegetation indices, it is calculated on the basis of satellite data.

calculation

The calculation of the soil-adjusted vegetation index is very similar to the NDVI . In addition to the degree of reflection in the near infrared (NIR) and in the red visible range (red), the empirically determined correction factor L is also included:

${\displaystyle \mathrm {SAVI} ={\frac {\mathrm {NIR} -\mathrm {rot} }{\mathrm {NIR} +\mathrm {rot} +L}}\cdot (1+L)}$

The factor L varies between 0 and 1, whereby smaller values ​​are assigned to it, the denser the vegetation is. Often 0.5 is used as the mean value. Since the soil-adjusted vegetation index is heavily dependent on L , the NDVI is preferred as the more robust index in most cases.

Modifications

There are several variations of the soil-adjusted vegetation index, e.g. B .:

• OSAVI (optimized soil-adjusted vegetation index )

${\displaystyle \mathrm {OSAVI} ={\frac {\mathrm {NIR} -\mathrm {rot} }{\mathrm {NIR} +\mathrm {rot} +Y}}}$

Author: Rondeaux, Steven & Baret, 1996

• TSAVI (transformed soil adjusted vegetation index )

${\displaystyle \mathrm {TSAVI} ={\frac {B(\mathrm {NIR} -BR-A)}{\mathrm {rot} +B(\mathrm {NIR} -A)+X(1+B^{2})}}}$

Author: Baret & Guyot, 1994

• MSAVI ( modified soil adjusted vegetation index )

${\displaystyle \mathrm {MSAVI} ={\frac {2\cdot \mathrm {NIR} +1-{\sqrt {(2\cdot \mathrm {NIR} +1)^{2}-8\cdot (\mathrm {NIR} -\mathrm {rot} )}}}{2}}}$

Author: Qi, Chehbouni, Huete, Kerr & Sorooshian, 1994

• MSAVI2