ndbi: Normalized Difference Built-up Index

In ASIP: Automated Satellite Image Processing

Description

Normalized Difference Built-up Index (NDBI) is used for mapping built-up areas

Usage

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

Arguments

ext2crop, crop, directory

Same as mentioned in arvi.

Value

Computed NDBI product

Note

1. NDBI= (r_swir1 - r_nir)/ (r_swir1 + r_nir)

where, "r_" denotes TOA reflectance band.

Other important notes are mentioned in custom.eqn.

References

Zha Y, Gao J and Ni S (2003) Use of normalized difference built-up index in automatically mapping urban areas from TM imagery. International Journal of Remote Sensing, 24 (3), pp:583-594. doi:10.1080/01431160304987.

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 <- ndbi (directory = path, crop = "y", ext2crop = shapefil)

Example output

Loading required package: sp
rgdal: version: 1.5-18, (SVN revision 1082)
Geospatial Data Abstraction Library extensions to R successfully loaded
Loaded GDAL runtime: GDAL 3.0.4, released 2020/01/28
Path to GDAL shared files: /usr/share/gdal
GDAL binary built with GEOS: TRUE 
Loaded PROJ runtime: Rel. 6.3.1, February 10th, 2020, [PJ_VERSION: 631]
Path to PROJ shared files: /usr/share/proj
Linking to sp version:1.4-4
To mute warnings of possible GDAL/OSR exportToProj4() degradation,
use options("rgdal_show_exportToProj4_warnings"="none") before loading rgdal.
sh: 1: awk: Permission denied
sh: 1: awk: Permission denied
sh: 1: awk: Permission denied
sh: 1: awk: Permission denied
sh: 1: awk: Permission denied
sh: 1: awk: Permission denied
sh: 1: awk: Permission denied
sh: 1: awk: Permission denied
sh: 1: awk: Permission denied
sh: 1: awk: Permission denied
sh: 1: awk: Permission denied
sh: 1: awk: Permission denied
sh: 1: awk: Permission denied
sh: 1: awk: Permission denied
sh: 1: awk: Permission denied
sh: 1: awk: Permission denied
sh: 1: awk: Permission denied
sh: 1: awk: Permission denied
sh: 1: awk: Permission denied

ASIP documentation built on May 1, 2019, 10:17 p.m.