User–Defined Linear Image Combination

  Raster Linear Combination Coefficients

The User–Defined Linear Image Combination process uses an array of coefficients to perform a linear combination operation on the input image bands. After adding the input rasters in the correct order, manually set up the array or use the Open Array option to choose a previously saved .arr file. The array can be saved and reused to quickly and accurately set up future operations. In this way, saved .arr files let you easily set up, modify, and reuse coefficients for your linear equations.

The .arr files below ( define a Tasseled Cap transformation that can be used to produce greenness, brightness, and wetness rasters. The coefficients within have been obtained from various sources and are provided as–is. Note that the tasseled cap transformation requires satellite–specific coefficients.

  • tasseled_cap_ASTER_at_sen_rad.arr
  • tasseled_cap_ASTER_at_sen_refl.arr
  • tasseled_cap_CBERS_02B.arr
  • tasseled_cap_DMC.arr
  • tasseled_cap_IKONOS.arr
  • tasseled_cap_Landsat7_ETM_at_satellite_reflectance.arr
  • tasseled_cap_Landsat8_ETM_at_satellite_reflectance.arr
  • tasseled_cap_LandsatMSS_Kauth_Thomas.arr
  • tasseled_cap_LandsatTM.arr
  • tasseled_cap_LandsatTM_surface_reflectance_Crist1985.arr
  • tasseled_cap_LandsatTM_TNTtmips2014.arr
  • tasseled_cap_LandsatTM_wikipedia2020.arr
  • tasseled_cap_Landsat_all_forest_surface_reflectance.arr
  • tasseled_cap_MODIS_NBARs.arr
  • tasseled_cap_QuickBird2.arr
  • tasseled_cap_RapidEye.arr
  • tasseled_cap_Sentinel2.arr
  • tasseled_cap_Thematic_Mapper_Crist_Cicone.arr
  • tasseled_cap_WorldView.arr

Tip: Open the .arr file in a text editor to verify what input bands to use and what order to add them. The process requires that the correct number of input bands are loaded prior to selecting the .arr file. Optionally edit .arr files to modify the coefficients as well as the desired input and output bands.

See also:
   Combining Rasters tutorial (page 11)
   Generalized Mapping of Biophysical Properties technical guide
   Kauth's Tasseled Cap or Kauth's greenness / brightness / wetness
   FAQs by JackTM F

The information on this page replaces the Compute TM Tasseled Cap Indices exercise steps in the Combining Rasters tutorial (page 11).