Vegetation Index Filter

Calculates a predefined vegetation index for reflectances.

Category	Math
Node
Parameters	Index: which vegetation index should be calculated Blue/From and To: Which wavelength range should be averaged to obtain the blue value for the specific index (if applicable) Green/From and To: Which wavelength range should be averaged to obtain the green value for the specific index (if applicable) Red/From and To: Which wavelength range should be averaged to obtain the red value for the specific index (if applicable) NIR/From and To: Which wavelength range should be averaged to obtain the NIR value for the specific index (if applicable) SWIR/From and To: Which wavelength range should be averaged to obtain the SWIR value for the specific index (if applicable)
Inputs	Input: the input data
Outputs	Output: the vegetation index

Effect of the Filter

The filter supports a variety of predefined vegetation indices. These indices consist of a formula that is applied to a set of virtual bands. The values of these bands is determined by averaging over wavelength ranges in the input reflectance data. These ranges can be adjusted by the user to suit the specific use case.

The following vegetation indices are supported:

Index	Formula
CIgreen	$I = n / g - 1$
CVI	$I = n \cdot r / g^2$
EVI	$I = 2.5 \cdot (n - r) / (n + 6\cdot r - 7.5\cdot b + 1)$
mNDVI	$I = (n - r) / (n + r - s)$
NDVI	$I = (n - r) / (n + r)$
OSAVI	$I = (n - r) / (n + r + 0.16)$
SAVI	$I = (n - r) / (n + r + 0.5) \cdot 1.5$

Here, $b$ is the blue band, $g$ the green band, $r$ the red band, $n$ the NIR band, and $s$ the SWIR band.