GRASS GIS manual: i.spectral

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NAME

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

KEYWORDS

imagery, raster, multispectral

SYNOPSIS

i.spectral
i.spectral help
i.spectral [-imc] [group=string] [raster=string[,string,...]] [output=string] [--overwrite] [--verbose] [--quiet]

Flags:

-i: Use image list and not group
-m: Select multiple points
-c: Show pick coordinates instead of numbering in the legend
--overwrite: Allow output files to overwrite existing files
--verbose: Verbose module output
--quiet: Quiet module output

Parameters:

group=string: Group input
raster=string[,string,...]: Raster input maps
output=string: Write output to PNG image

DESCRIPTION

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

NOTES

This script needs gnuplot to be installed.

EXAMPLES

Analysis of LANDSAT TM7 channels (North Carolina dataset):

g.region rast=lsat7_2002_10 -p
d.mon x0
d.rast lsat7_2002_40
i.spectral -i rast=lsat7_2002_10,lsat7_2002_20,lsat7_2002_30,lsat7_2002_40,lsat7_2002_50,lsat7_2002_70

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

To analyze a time series of maps, use:

d.rast map_1
LIST=`g.mlist type=rast mapset=timeseries pat="map_*" | sort -t '_' -k 2 -n | tr '\n' ','| sed 's+,$++g'`
i.spectral -i rast=$LIST

This will search all maps in the mapset 'timeseries' which match have the 'map_' prefix and order by a number following this prefix (day of the year etc). The user is then asked to click into a map position and the resulting pixel values of all matching maps are drawn in the gnuplot output.

AUTHOR

Markus Neteler
Francesco Pirotti

Last changed: $Date: 2012-08-20 03:35:34 -0700 (Mon, 20 Aug 2012) $

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