NAME

       i.tasscap  - Performs Tasseled Cap (Kauth Thomas) transformation.

KEYWORDS

       imagery, transformation, Landsat, MODIS, Worldview, Sentinel, 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; for Sentinel-2: bands 1 to 12, 8A; for Worldview-2: bands 1, 2, 3, 4, 5, 6, 7, 8

       output=basename [required]
           basename for output 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, sentinel2, worldview2

DESCRIPTION

       i.tasscap calculates Tasseled Cap (Kauth Thomas, TC) transformation for Landsat TM data (TM4, TM5, ETM7),
       MODIS and Sentinel-2 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 pre-processing
       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 (PDF).  This is
               published as well in INT. J. OF RS, 2002, VOL 23, NO. 8, 1741-1748.

           •   MODIS Tasseled Cap coefficients - Ref: Lobser & Cohen (2007).  MODIS  tasseled  cap:  land  cover
               characteristics  expressed  through  transformed  MODIS  data.   International  Journal of Remote
               Sensing, Volume 28(22), Table 3

           •   Sentinel-2 Tasseled Cap coefficients - Ref:  Nedkov,  R.  (2017).  Orthogonal  transformation  of
               segmented  images  from  the  satellite  Sentinel-2.   Comptes  rendus  de l’Académie bulgare des
               sciences, 70:687-692.

           •   Yarbrough, L., Navulur, R., 2014, Presentation of  the  Kauth-Thomas  transform  for  WorldView-2
               reflectance data. Remote Sensing Letters. 5. DOI: 10.1080/2150704X.2014.885148.

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

       Code improvements by Leonardo Perathoner

       Sentinel-2 support by Veronica Andreo

       Worldview-2 support by Markus Neteler

SOURCE CODE

       Available at: i.tasscap source code (history)

       Accessed: Friday Apr 04 01:21:11 2025

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       © 2003-2025 GRASS Development Team, GRASS GIS 8.4.1 Reference Manual

GRASS 8.4.1                                                                                    i.tasscap(1grass)