vi: Various vegetation indices

In environmentalinformatics-marburg/reset: Remote Sensing-Based Evapotranspiration

Description

Calculate various vegetation indices (VI) from red and near-infrared wavelengths. Currently available methods include the Normalized Difference Vegetation Index (Tucker 1979), the Soil-adjusted Vegetation Index (Huete 1988), and the Wide Dynamic Range Vegetation Index (Gitelson 2004).

Usage

ndvi(red, nir, cores = 1L, filename = "", ...)

savi(red, nir, L = 0.5, cores = 1L, filename = "", ...)

wdrvi(red, nir, ndvi = NULL, alpha = 0.2, cores = 1L, filename = "",
  ...)

Arguments

red	Raster* object, red band.
nir	Raster* object, near-infrared band.
cores	Number of cores for parallel computing. If cores > 1L, a separate filename is required for each layer in red (and nir).
filename	Output filename (optional).
...	Additional arguments passed on to writeRaster.
L	numeric canopy background adjustment factor, defaults to 0.5.
ndvi	Raster* object, e.g., derived from ndvi. If specified, arguments red and nir are automatically ignored.
alpha	numeric weighting coefficient, defaults to 0.2.

Value

The calculated VI as Raster* object.

Functions

• ndvi: Normalized Difference Vegetation Index (Tucker 1979)

• savi: Soil-adjusted Vegetation Index (Huete 1988)

• wdrvi: Wide Dynamic Range Vegetation Index (Gitelson 2004)

Author(s)

Florian Detsch

References

Gitelson, A.A. (2004). Wide dynamic range vegetation index for remote quantification of crop biophysical characteristics. Journal of Plant Physiology 161, 165-173, doi:10.1078/0176-1617-01176. Available online at http://www.sciencedirect.com/science/article/pii/S0176161704705726 (accessed on 2016-07-22).

Huete, A.R. (1988). A Soil-Adjusted Vegetation Index (SAVI). Remote Sensing of Environment 25, 295-309, doi:10.1016/0034-4257(88)90106-X. Available online at http://www.sciencedirect.com/science/article/pii/003442578890106X (accessed on 2016-03-02).

Tucker, C.J. (1979). Red and photographic infrared linear combinations for monitoring vegetation. Remote Sensing of Environment 8, 127-150, doi:10.1016/0034-4257(79)90013-0. Available online at http://www.sciencedirect.com/science/article/pii/0034425779900130 (accessed on 2016-03-02).

environmentalinformatics-marburg/reset documentation built on May 16, 2019, 7:54 a.m.