i.tasscap (1)
NAME
i.tasscap - Performs Tasseled Cap (Kauth Thomas) transformation.
KEYWORDS
imagery, transformation, Landsat, MODIS, Tasseled Cap transformation
SYNOPSIS
i.tasscap
i.tasscap --help
i.tasscap input=name[,name,...] output=basename sensor=string [--overwrite] [--help] [--verbose] [--quiet] [--ui]
Flags:
--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:
input=name[,name,...] [required]
For Landsat4-7: bands 1, 2, 3, 4, 5, 7; for Landsat8: bands 2, 3, 4, 5, 6, 7; for MODIS: bands 1, 2, 3, 4, 5, 6, 7
output=basename [required]
Name for output basename raster map(s)
Name for output basename raster map(s)
sensor=string [required]
Satellite sensor
Options: landsat4_tm, landsat5_tm, landsat7_etm, landsat8_oli, modis
landsat4_tm: Use transformation rules for Landsat 4 TM
landsat5_tm: Use transformation rules for Landsat 5 TM
landsat7_etm: Use transformation rules for Landsat 7 ETM
landsat8_oli: Use transformation rules for Landsat 8 OLI
modis: Use transformation rules for MODIS
DESCRIPTION
i.tasscap calculates Tasseled Cap (Kauth Thomas, TC) transformation for Landsat TM data (TM4, TM5, ETM7) and MODIS data. 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+ are at-satellite reflectance values (C. Huang et al., 2001), the conversion can be achieved with i.landsat.toar.
The following tasseled cap components are generated:
o tasscap.1: corresponds to brightness,
o tasscap.2: corresponds to greenness,
o tasscap.3: corresponds to wetness,
o tasscap.4: corresponds to atmospheric haze (only selected sensors: Landsat 5,7,8).
EXAMPLE
Calculation of TC maps from North Carolina Landsat 7 ETM scene:
# See manual page of i.landsat.toar for preprocessing
g.region raster=lsat7_2002_toar.1 -p
i.tasscap sensor=landsat7_etm \
input=lsat7_2002_toar.1,lsat7_2002_toar.2,lsat7_2002_toar.3,lsat7_2002_toar.4,lsat7_2002_toar.5,lsat7_2002_toar.7 \
output=lsat7_2002_tasscap
Results:
'Brightness' Tasseled Cap component 1 'Greenness' Tasseled Cap component 2
'Wetness' Tasseled Cap component 3 'Atmospheric haze' Tasseled Cap component 4
REFERENCES
o LANDSAT-4/LANDSAT-5: TC-factor changed to CRIST et al. 1986, Proc. IGARSS 1986, p.1467
o Crist, E. P., 1985, A TM tasseled cap equivalent transformation for reflectance factor data, Remote Sensing of Environment, 17: 301-306.
o 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.
o MODIS Tasselled Cap coefficients - Ref: Lobser & Cohen (2007). MODIS tasselled cap: land cover characteristics expressed through transformed MODIS data. International Journal of Remote Sensing, Volume 28(22), Table 3
SEE ALSO
i.albedo, i.atcorr, i.landsat.toar, i.vi
AUTHORS
Dr. Agustin Lobo, original script, 1997
Markus Neteler, ITC-irst, 2001
Converted to Python by Glynn Clements
Last changed: $Date: 2016-12-28 21:57:16 +0100 (Wed, 28 Dec 2016) $
SOURCE CODE
Available at: i.tasscap source code (history)
Main index | Imagery index | Topics index | Keywords index | Graphical index | Full index
2003-2017 GRASS Development Team, GRASS GIS 7.2.1 Reference Manual