i.spectral - GRASS GIS manual

NAME

i.spectral - Displays spectral response at user specified locations in group or images.

KEYWORDS

imagery, querying, raster, multispectral

SYNOPSIS

i.spectral

i.spectral --help

i.spectral [-cgt] [group=name] [subgroup=name] [raster=name[,name,...]] coordinates=east,north[,east,north,...] [output=name] [format=string] [--overwrite] [--help] [--verbose] [--quiet] [--ui]

Flags:

-c: Show sampling coordinates instead of numbering in the legend (valid for -g flag)
-g: Use gnuplot for display
-t: output to text file
--overwrite: Allow output files to overwrite existing files
--help: Print usage summary
--verbose: Verbose module output
--quiet: Quiet module output
--ui: Force launching GUI dialog

Parameters:

group=name: Name of input imagery group
subgroup=name: Name of input imagery subgroup
raster=name[,name,...]: Name of input raster map(s)
coordinates=east,north[,east,north,...] [required]: Coordinates
output=name: Name for output image is valid for -g (or text file for -t flag)
format=string: Graphics format for output file (valid for -g flag); Options: png, eps, svg; Default: png

DESCRIPTION
NOTES
EXAMPLE
SEE ALSO
AUTHORS

DESCRIPTION

i.spectral displays spectral response at user specified locations in images.

NOTES

This script requires the launch of one of the supported monitors (cairo, png, ps) or gnuplot to be installed.

EXAMPLE

Analysis of LANDSAT TM7 channels (North Carolina dataset):

g.region raster=lsat7_2002_10 -p
i.spectral -g raster=lsat7_2002_10,lsat7_2002_20,lsat7_2002_30,lsat7_2002_40,lsat7_2002_50,lsat7_2002_70 \
           coordinates=636069,215440,637958,223393,633277,223605

Spectral plot of 3 different land cover types: (1) water, (2) green vegetation, and (3) highway

North Carolina sample dataset:

g.region raster=lsat7_2002_10 -p
LIST=`g.list type=raster pattern="lsat7_2002_[1-5,7]0" separator=","`
d.mon start=cairo output=plot.png
i.spectral raster=$LIST coordinates=637502.25,221744.25
d.mon stop=cairo

This will search all LANDSAT map for 2002 but select only the B, G, R, NIR, and MIR channels.

AUTHORS

Markus Neteler
Francesco Pirotti

SOURCE CODE

Available at: i.spectral source code (history)

Latest change: Thursday Jan 26 14:10:26 2023 in commit: cdd84c130cea04b204479e2efdc75c742efc4843