Generates a tasseled cap image from either an MSS or TM image.
Generates a tasseled cap image from either a Landsat MSS or TM image. Because of the complexities involved with display and extraction of information contained in multispectral scanner data, a variety of approaches have been taken to combine multiple band responses into a lesser number of features which reduce the overall data volume and/or enhance the ability to extract particular types of scene class information. The tasseled cap transformations of MSS and TM data accomplish the above goals by providing linear combinations of the original sensor bands which respond primarily to particular physical scene class characteristics and capture considerably more of the total data variability (in scenes dominated by vegetation and soils) in one-half the original number of bands.
- IN
- Input image. The Landsat MSS or TM image to be used in the calculations. The data type may be BYTE, INTEGER*2, INTEGER*4, or REAL*4. A window may be specified.
- OUT
- Output image. The output image consisting of bright, green, and/or wet bands determined by the BANDS parameter. The output data type is determined from the ODTYPE parameter.
- BANDS(BRIGHT,GREEN,WET)
- Output bands desired. Not all three bands need to be created. If desired, the bright band can be created alone, the bright band along with the green band can be created, or all three bands can be created.
- PRINT(TERM)
- Output destination. The destination of the output.
= --: No Report = TERM: Terminal. Output is sent to the user's terminal. = LP: Line printer. Output is sent to the printer defined by $PRINTER. = Filename: User-supplied filename. Output is sent to the user-supplied file with the extension ".prt".
- ODTYPE(SAME)
- Output data type. The data type of the output image.
= SAME: Same as input = BYTE: BYTE (8-bit unsigned integer) (0 through 255) = I*2: INTEGER*2 (16-bit signed integer) (-32768 through 32767) = I*4: INTEGER*4 (32-bit signed integer) (-2147483648 through 2147483647) = R*4: REAL*4 (32-bit signed real) (System dependent)
- BRIGHTCO(0.2909,0.2493,0.4806,0.5568,0.4438,0.1706)
- Brightness coefficients. Brightness, a weighted sum of all six bands, is a measure of overall reflectance (e.g., differentiating dry from wet soils). The defaults are for Landsat 5 Thematic Mapper (TM) data. If Landsat 4 TM defaults are to be used, they are 0.3037, 0.2793, 0.4743, 0.5585, 0.5082, and 0.1863 .
- GREENCO(-0.2728,-0.2174,-0.5508,0.7221,0.0733,-0.1648)
- Greenness coefficients. Greenness is a contrast between near-infrared and visible reflectance and is thus a measure of the presence and density of green vegetation. The defaults are for Landsat 5 Thematic Mapper (TM) data. If Landsat 4 TM defaults are to be used, they are -0.2848, -0.2435, -0.5436, 0.7243, 0.0840, and -0.1800 .
- WETCO(0.1446,0.1761,0.3322,0.3396,-0.6210,-0.4186)
- Wetness coefficients. Wetness is a contrast between shortwave-infrared (SWIR) and visible/near-infrared (VNIR) reflectance, providing a measure of soil moisture content, vegetation density, and other scene class characteristics. The defaults are for Landsat 5 Thematic Mapper (TM) data. If Landsat 4 TM defaults are to be used, they are 0.1509, 0.1973, 0.3279, 0.3406, -0.7112, and -0.4572 .
- IN
- Input image. The Landsat MSS or TM image to be used in the calculations. The data type may be BYTE, INTEGER*2, INTEGER*4, or REAL*4. A window may be specified.
- OUT
- Output image. The output image consisting of bright, green, and/or wet bands determined by the BANDS parameter. The output data type is determined from the ODTYPE parameter.
- BANDS(BRIGHT,GREEN,WET)
- Output bands desired. Not all three bands need to be created. If desired, the bright band can be created alone, the bright band along with the green band can be created, or all three bands can be created.
- PRINT(TERM)
- Output destination. The destination of the output.
= --: No Report = TERM: Terminal. Output is sent to the user's terminal. = LP: Line printer. Output is sent to the printer defined by $PRINTER. = Filename: User-supplied filename. Output is sent to the user-supplied file with the extension ".prt".
- ODTYPE(SAME)
- Output data type. The data type of the output image.
= SAME: Same as input = BYTE: BYTE (8-bit unsigned integer) (0 through 255) = I*2: INTEGER*2 (16-bit signed integer) (-32768 through 32767) = I*4: INTEGER*4 (32-bit signed integer) (-2147483648 through 2147483647) = R*4: REAL*4 (32-bit signed real) (System dependent)
- DRYSOIL(0.0,0.0,0.0,0.0,0.0,0.0)
- Mean dry soil. The pixel value considered to be the mean value for dry or bright soil. It is used, along with the WETSOIL parameter, to calculate the brightness coefficients. In addition, it is used with GRNVEG to produce the greenness coefficients and with DRYVEG to produce the wetness coefficients.
- WETSOIL(0.0,0.0,0.0,0.0,0.0,0.0)
- Mean wet soil. The pixel value considered to be the mean value for wet or dark soil. It is used, along with the DRYSOIL parameter, to calculate the brightness coefficients.
- GRNVEG(0.0,0.0,0.0,0.0,0.0,0.0)
- Mean green vegetation. The pixel value considered to be the mean value for green vegetation. It is used, along with the DRYSOIL parameter, to calculate the greenness coefficients.
- DRYVEG(0.0,0.0,0.0,0.0,0.0,0.0)
- Mean dry vegetation. The pixel value considered to be the mean value for dry vegetation. It is used, along with the DRYSOIL parameter, to calculate the wetness coefficients.
The DRYSOIL, WETSOIL, GRNVEG, and DRYVEG parameters are used to calculate the brightness, greenness, and wetness coefficients. Once the coefficients are generated, they are applied to the input image LANDSAT5.MSS to produce a three-band image TASSELOUT.BGW consisting of three bands considered to be bright, green, and wet bands. The data type is the same as the input image.
The BRIGHTCO, GREENCO, and WETCO parameters are applied to the image LANDSAT4.TM, giving a three-band image TASSELOUT.BGW. A report is generated and written to the desired printer showing the parameter used along with the orthogonality. The output data type is INTEGER*2.
There are two subcommands, -CREATE and -APPLY, involved with the tasseled cap transformation module. If the brightness, greenness, and wetness coefficients are known, then the -APPLY subcommand should be run; otherwise, the user needs to supply pixel values from their particular image to the -CREATE subcommand. This subcommand generates the necessary coefficients and optionally applies them.Within the -CREATE subcommand the following algorithm is applied:
For the brightness coefficients: _______________________________ For all bands, 1 to N, do the following: Step 1. BVALUE = SQRT(((DRYSOIL(BAND 1) - WETSOIL(BAND 1)) ** 2) + (DRYSOIL(BAND 2) - WETSOIL(BAND 2)) ** 2) + . . . . (DRYSOIL(BAND N) - WETSOIL(BAND N)) ** 2)) Step 2. BRIGHTCO(BAND 1) = (DRYSOIL(BAND 1) - WETSOIL(BAND 1)) / BVALUE BRIGHTCO(BAND 2) = (DRYSOIL(BAND 2) - WETSOIL(BAND 2)) / BVALUE . . . . BRIGHTCO(BAND N) = (DRYSOIL(BAND N) - WETSOIL(BAND N)) / BVALUE For the greenness coefficients: ______________________________ For all bands, 1 to N, do the following: Step 1. GVALUE=((GRNVEG(BAND 1) - DRYSOIL(BAND 1)) * BRIGHTCO(BAND 1) + (GRNVEG(BAND 2) - DRYSOIL(BAND 2)) * BRIGHTCO(BAND 2) + . . . . (GRNVEG(BAND N) - DRYSOIL(BAND N)) * BRIGHTCO(BAND N)) Step 2. GRNTEMP(BAND 1)=(GRNVEG(BAND 1) - DRYSOIL(BAND 1)) - (GVALUE * BRIGHTCO(BAND 1)) GRNTEMP(BAND 2)=(GRNVEG(BAND 2) - DRYSOIL(BAND 2)) - (GVALUE * BRIGHTCO(BAND 2)) GRNTEMP(BAND N)=(GRNVEG(BAND N) - DRYSOIL(BAND N)) - (GVALUE * BRIGHTCO(BAND N)) Step 3. DIVVAL=SQRT((GRNTEMP(BAND 1) ** 2) + (GRNTEMP(BAND 2) ** 2) + (GRNTEMP(BAND N) ** 2)) GREENCO(BAND 1) = GRNTEMP(BAND 1) / DIVVAL GREENCO(BAND 2) = GRNTEMP(BAND 2) / DIVVAL . . . . GREENCO(BAND N) = GRNTEMP(BAND N) / DIVVAL For the wetness coefficients: ____________________________ For all bands, 1 to N, do the following: Step 1. WVALUE(BAND 1) = DRYVEG(BAND 1) - DRYSOIL(BAND 1) BTEMP = ((DRYVEG(BAND 1) - DRYSOIL(BAND 1) * BRIGHTCO(BAND 1)) GTEMP = ((DRYVEG(BAND 1) - DRYSOIL(BAND 1) * GREENCO(BAND 1)) WVALUE(BAND 2) = DRYVEG(BAND 2) - DRYSOIL(BAND 2) BTEMP = BTEMP + (WVALUE(BAND 2) * BRIGHTCO(BAND 2)) GTEMP = GTEMP + (WVALUE(BAND 2) * GREENCO(BAND 2)) . . . . WVALUE(BAND N) = DRYVEG(BAND N) - DRYSOIL(BAND N) BTEMP = BTEMP + (WVALUE(BAND N) * BRIGHTCO(BAND N)) GTEMP = GTEMP + (WVALUE(BAND N) * GREENCO(BAND N)) Step 2. WVALUE(BAND 1)=WVALUE(BAND 1) - ((BTEMP * BRIGHTCO(BAND 1)) + (GTEMP * GREENCO(BAND 1)) DIVVAL = WVALUE(BAND 1) * WVALUE(BAND 1) WVALUE(BAND 2)=WVALUE(BAND 2) - ((BTEMP * BRIGHTCO(BAND 2)) + (GTEMP * GREENCO(BAND 2)) DIVVAL = DIVVAL + (WVALUE(BAND 2) * WVALUE(BAND 2)) . . . . WVALUE(BAND N)=WVALUE(BAND N) - ((BTEMP * BRIGHTCO(BAND N)) + (GTEMP * GREENCO(BAND N)) DIVVAL = DIVVAL + (WVALUE(BAND N) * WVALUE(BAND N)) Step 3. DIVVAL = SQRT(DIVVAL) WETCO(BAND 1) = WVALUE(BAND 1) / DIVVAL WETCO(BAND 2) = WVALUE(BAND 2) / DIVVAL . . . . WETCO(BAND N) = WVALUE(BAND N) / DIVVAL Where: DRYSOIL = Mean dry soil value for each band WETSOIL = Mean wet soil value for each band GRNVEG = Mean green vegetation value for each band DRYVEG = Mean senesced value for each band For the calculation of orthogonality: ____________________________________ Brightness/Greenness or BG BG = (BRIGHTCO(BAND 1) * GREENCO(BAND 1)) + (BRIGHTCO(BAND 2) * GREENCO(BAND 2)) + . . . . + GREENCO(BAND N)) * (BRIGHTCO(BAND N) Brightness/Wetness or BW BW = (BRIGHTCO(BAND 1) * WETCO(BAND 1)) + (BRIGHTCO(BAND 2) * WETCO(BAND 2)) + . . . . + WETCO(BAND N)) * (BRIGHTCO(BAND N) * Greenness/Wetness or GW GW = (GREENCO(BAND 1) * WETCO(BAND 1)) + (GREENCO(BAND 2) * WETCO(BAND 2)) + . . . . + WETCO(BAND N)) * (GREENCO(BAND N) *Within the -APPLY subcommand the following algorithm is applied to every image pixel:
BRIGHTNESS = (BRIGHTCO(BAND 1) * PIXELVAL(BAND 1)) + . . . . (BRIGHTCO(BAND N) * PIXELVAL(BAND N)) GREENNESS = (GREENCO(BAND 1) * PIXELVAL(BAND 1)) + . . . . (GREENCO(BAND N) * PIXELVAL(BAND N)) WETNESS = (WETCO(BAND 1) * PIXELVAL(BAND 1)) + . . . . (WETCO(BAND N) * PIXELVAL(BAND N)) Reference: R. D. Jackson, 1983. Spectral Indices in n-Space, Remote Sensing of Environment, 13:409-421.
A nonfatal error was encountered during processing. The image data is probably valid and is therefore saved. The message that is displayed immediately preceding this message is the specific error that was encountered from a library routine. Processing continues.
An error occurred while trying to close the appropriate files. They may be left on disk even with the global $DELFLG being turned on.
An error occurred in updating the DDR file with the minimum and maximum pixel values. The image data is saved.
An error occurred while trying to dynamically allocate buffer space.
A fatal error was encountered during processing. The output image is not deleted; however, it is probably not valid. The error message that is displayed immediately preceding this message is the specific error that was encountered.
An error was encountered attempting to open the input image.
An error was encountered attempting to open the output image.
The images specified have a different number of lines and/or samples. Respecify by using the windowing option.