GRASS GIS manual: i.tasscap

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NAME

i.tasscap - Tasseled Cap (Kauth Thomas) transformation for LANDSAT-TM data

KEYWORDS

raster, imagery

SYNOPSIS

i.tasscap
i.tasscap help
i.tasscap [-457s] band1=string band2=string band3=string band4=string band5=string band7=string outprefix=string [--overwrite] [--verbose] [--quiet]

Flags:

-4: use transformation rules for LANDSAT-4
-5: use transformation rules for LANDSAT-5
-7: use transformation rules for LANDSAT-7
-s: Process bands serially (default: run in parallel)
--overwrite: Allow output files to overwrite existing files
--verbose: Verbose module output
--quiet: Quiet module output

Parameters:

band1=string: raster input map (LANDSAT channel 1)
band2=string: raster input map (LANDSAT channel 2)
band3=string: raster input map (LANDSAT channel 3)
band4=string: raster input map (LANDSAT channel 4)
band5=string: raster input map (LANDSAT channel 5)
band7=string: raster input map (LANDSAT channel 7)
outprefix=string: raster output TC maps prefix

DESCRIPTION

i.tasscap calculates Tasseled Cap (Kauth Thomas, TC) transformation for LANDSAT-TM data (TM4, TM5, TM7). The tasseled cap transformation is effectively a compression method to reduce multiple spectral data into a few bands. The method was originally developed for understanding important phenomena of crop development in spectral space (Kauth and Thomas 1976).

Tasseled cap coefficients for Landsat 7 ETM+ at-satellite reflectance (C. Huang et al., 2001), the conversion can be achieved with i.landsat.toar.

The following TC components are generated:

tasscap.1: corresponds to brightness,
tasscap.2: corresponds to greenness,
tasscap.3: corresponds to wetness,
tasscap.4: corresponds to atmospheric haze.

EXAMPLE

Calculation of TC maps from North Carolina Landsat scene:

g.region rast=lsat7_2002_10 -p
i.tasscap -7 band1=lsat7_2002_10 band2=lsat7_2002_20 \
             band3=lsat7_2002_30 band4=lsat7_2002_40 \
             band5=lsat7_2002_50 band7=lsat7_2002_70 \
	     outprefix=tasscap
# display
d.mon x0
d.split.frame
d.frame uno; d.rast tasscap.1
d.frame dos; d.rast tasscap.2
d.frame tres; d.rast tasscap.3
d.frame cuatro; d.rast tasscap.4

Results:

'Brightness' Tasseled Cap component 1	'Greenness' Tasseled Cap component 2
'Wetness' Tasseled Cap component 3	'Atmospheric haze' Tasseled Cap component 4

REFERENCES

LANDSAT-4/LANDSAT-5: TC-factor changed to CRIST et al. 1986, Proc. IGARSS 1986, p.1467
Crist, E. P., 1985, A TM tasseled cap equivalent transformation for reflectance factor data, Remote Sensing of Environment, 17: 301-306.
LANDSAT-7: TASSCAP factors cited from: DERIVATION OF A TASSELED CAP TRANSFORMATION BASED ON LANDSAT 7 AT-SATELLITE REFLECTANCE Chengquan Huang, Bruce Wylie, Limin Yang, Collin Homer and Gregory Zylstra Raytheon ITSS, USGS EROS Data Center Sioux Falls, SD 57198, USA http://landcover.usgs.gov/pdf/tasseled.pdf
This is published as well in INT. J. OF RS, 2002, VOL 23, NO. 8, 1741-1748.
Compare discussion: http://adis.cesnet.cz/cgi-bin/lwgate/IMAGRS-L/archives/imagrs-l.log0211/date/article-14.html

AUTHOR

Markus Neteler, ITC-irst

Last changed: $Date: 2013-11-06 22:13:10 -0800 (Wed, 06 Nov 2013) $

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