msavi {ASIP}

R Documentation

Modified soil adjusted vegetation index

Description

Modified Soil Adjusted Vegetation Index (MSAVI) is a vegetation index. Advantage of this index is that, it increases the dynamic range of the vegetation signal while further minimizing the soil background influences, resulting in greater vegetation sensitivity as defined by a 'vegetation signal' to 'soil noise' ratio.

Usage

msavi(directory = getwd(), crop = "n", ext2crop = "none")

Arguments

ext2crop, crop, directory

Same as mentioned in arvi.

Value

Computed MSAVI product

Note

1. MSAVI=((2r_nir + 1) - ((2r_nir + 1)^2 - 8(r_nir - r_red))^0.5)/2

where, "r_" denotes TOA reflectance band.

Other important notes are mentioned in custom.eqn.

References

Qi J, Chehbouni A, Huete A R, Kerr Y, Sorooshian S (1994) A modified soil adjusted vegetation index. Remote Sensing of Environment, 48 (2), pp: 119-126. doi:10.1016/0034-4257(94)90134-1.

Examples

library (raster)
library (rgdal)
# Finding the path of the sample satellite image directory.
# User may define paths directly like "/home/ur_folder" or "C:/ur_folder"
path <- system.file ("TM_sample", package = "ASIP")
shapefil <- paste0 (path, "/test.shp")
op <- msavi (directory = path, crop = "y", ext2crop = shapefil)

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