NDWI: NDWI - Normalized Difference Water Index

In nightmares: Common Analysis with Remote Sensing Data

Description

This index is designed to maximize reflectance of water by using green wavelengths; minimize the low reflectance of NIR by water features; and take advantage of the high reflectance of NIR by vegetation and soil features. Water features have positive values and thus are enhanced, while vegetation and soil usually have zero or negative values and therefore are suppressed.The NDWI is useful in crop health monitoring, land-water boarding mapping, inland water discrimination from open sea water bodies, among others.

Usage

NDWI(G, NIR)

Arguments

G	A raster layer object with the reflectance values for the Green band.
NIR	A raster layer object with the reflectance values for the Near Infrared band.

Value

NDWI - Normalized Difference Water Index.

References

McFeeters, SK. 1996. The use of the Normalized Difference Water Index (NDWI) in the delineation of open water features. International Journal of Remote Sensing, 17(7), 1425-1432. https://www.geo.university/pages/spectral-indices-with-multispectral-satellite-data.

Examples

library(raster)
path_files <- system.file("extdata/", package="nightmares")
bands <- stack(list.files(path_files,".tif", full.names=TRUE))
x <- ref_oli(bands, sun.elev= 67.97)
NDWI(x[[3]], x[[5]])

nightmares documentation built on Oct. 23, 2020, 7:15 p.m.