Note: A new GRASS GIS stable version has been released: GRASS GIS 7.6, available here.
Updated manual page: here
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
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:
- tasscap.1: corresponds to brightness,
- tasscap.2: corresponds to greenness,
- tasscap.3: corresponds to wetness,
- tasscap.4: corresponds to atmospheric haze (only selected sensors: Landsat 5,7,8).
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
|
- 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.
- 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
i.albedo,
i.atcorr,
i.landsat.toar,
i.vi
Dr. Agustin Lobo, original script, 1997
Markus Neteler, ITC-irst, 2001
Converted to Python by Glynn Clements
Last changed: $Date: 2018-03-04 04:10:09 -0800 (Sun, 04 Mar 2018) $
SOURCE CODE
Available at: i.tasscap source code (history)
Note: A new GRASS GIS stable version has been released: GRASS GIS 7.6, available here.
Updated manual page: here
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GRASS Development Team,
GRASS GIS 7.2.4svn Reference Manual