GRASS GIS manual: i.tasscap

Note: A new GRASS GIS stable version has been released: GRASS GIS 7.8, 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

DESCRIPTION
EXAMPLE
REFERENCES
SEE ALSO
AUTHORS

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:

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).

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

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

AUTHORS

Dr. Agustin Lobo, original script, 1997

Markus Neteler, ITC-irst, 2001

Converted to Python by Glynn Clements

Last changed: $Date$

SOURCE CODE

Available at: i.tasscap source code (history)