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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

Table of contents

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.

SEE ALSO

d.where, r.what, Cairo driver, PNG driver, PS driver (Postscript)

AUTHORS

Markus Neteler
Francesco Pirotti

SOURCE CODE

Available at: i.spectral source code (history)

Latest change: Thursday Dec 02 08:02:56 2021 in commit: c4dcac886fa47e31da52a9df86b8d5c9ec27f563

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© 2003-2023 GRASS Development Team, GRASS GIS 7.8.9dev Reference Manual