unmix Documentation

unmix - Spectral unmixing
This program computes spectral unmixing using a specified set of
endmember spectra.  The endmember spectra can be obtained from either
an Instrument Spectral Library (ISL) file (e.g., average spectra for
regions produced by the CV program) or a table file.  In either case,
the ENDNAMES parameter specifies the names of the endmembers to use,
which are spectrum names for an ISL file or column names for a table
file.  Note that ISL spectrum names are case-sensitive but table file
column names are not case-sensitive.  If ENDNAMES is the NULL TAE
parameter, then all spectra in the file are used as endmembers.  A
maximum of twenty endmembers can be used.

The output file will contain a new backplane for each selected
endmember spectrum.  The name of each backplane will be the same as
the name of the endmember and the contents of the backplane will be
the computed fraction for that endmember.  Two additional backplanes
(named YSUM and UNMIX_ITERATIONS) will contain additional information
from the unmixing computation.  The core of the output cube will
contain the residual spectrum.

If SFROM selects a subset of the bands in the input cube, then the
same set of bands is selected from each endmember and only those bands
are used for the unmixing computations.  (It is assumed that the set
of wavelengths in the endmembers corresponds to the set of wavelengths
in the input cube.)

The CONST1 parameter allows selecting whether or not the fractions are
constrained to sum to 1.0.  (The fractions are always constrained to
be non-negative values.)

If an input spectrum does not contain enough valid pixels (specified
either as a count or a fraction of total pixels), then the output
residual spectrum and new backplanes are set to NULL pixel values.

The EANORM parameter allows specifying whether or not an equal area
normalization should be applied to the input spectra and endmember
spectra before doing the unmixing computation.

Suffix planes in the input cube file are propagated unchanged to the
output cube file.

PROGRAMMER: Jim Torson, U.S.G.S., Flagstaff, AZ

Input cube file name
  (default extension is .cub)

NONE

Input subcube specifier

--

Output cube file name
  (default extension is .cub)

NONE

Endmember ISL file
  (default extension is .isl)

NONE

Endmember table file
  (default extension is .tbl)

--

Table object name

"TABLE"

Names of endmembers to use

--

Whether to constrain sum of
  fractions to 1.0 (YES or NO)

"YES"

Min valid pixel fraction

0.75

Min valid pixel count

--

Whether to equal area normalize
 (YES or NO)

"NO"

Equal area output average

1.0

Output pixel type
 NULL = input type
    1 = 8 bit
    2 = 16 bit
    3 = 32 bit

--

Output min/max data range

--

User comment

" "

ADDITIONAL NOTES:

Parm	Description
FROM	Input cube file name. If the file extension is omitted, then ".cub" will be assumed.
SFROM	SFROM specifies the subcube using a single string for all three dimensions of the cube. The order of the three dimensions is always "samples:lines:bands". If a dimension is left blank, all the data for that dimension is selected. The default value of NULL for SFROM selects the entire cube. Any application below can be used for any dimension. To select specific data from any dimension: "10-100(3):11,12,15-20:1-10(2)" = This example will select every third sample starting with sample 10 thru 100. It selects lines 11 and 12, and 15-20. It selects every other band, starting with band 1 thru 10. There are special characters that can be used for selecting a subcube efficiently, such as "*","#", and "~". For examples type "help sfrom" in TAE. **NOTE** For more examples and explanation of the many features of the SFROM parameter, tutor the sfrom.pdf or refer to Introduction To ISIS, Section 6, of the ISIS User's Manual **
TO	Output cube file name. If the file extension is omitted, then ".cub" will be assumed.
ISLFROM	Name of Instrument Spectral Library file that contains endmember spectra. This must be specified as the NULL TAE parameter value if the endmembers are to be obtained from a table file.
TBLFROM	Name of Table file that contains endmember spectra. This must be specified as the NULL TAE parameter value if the endmembers are to be obtained from an ISL file.
OBJNAME	Name of Table Object that contains the endmember spectra. (Used only when TBLFROM is specified.)
ENDNAMES	Names of the endmembers to be used. If the endmembers are being obtained from an ISL file, then this specifies spectrum names in the ISL. If the endmembers are being obtained from a Table file, then this specifies column names in the Table file. Note that ISL spectrum names are case-sensitive, but Table file column names are not case-sensitive. If ENDNAMES is set to the NULL TAE parameter value, then all spectra in the ISL file or all columns in the Table file are used.
CONST1	Specifies whether the computed fractions are constrained to sum to 1.0. Note that the fractions are always constrained to be non-negative values.
MINVFRAC	Minumum fraction of valid pixels that must be contained in a spectrum in order for it to be processed. If there are not enough valid pixels, then the output values for that spectrum are all set to NULLs.
MINVCNT	Minumum count of valid pixels that must be contained in a spectrum in order for it to be processed. If there are not enough valid pixels, then the output values for that spectrum are all set to NULLs.
EANORM	Specifies whether an equal area normalization operation is to be done on the endmember spectra and the spectra from the input cube file. If EANORM=YES is specified, then each spectrum is multiplied by a factor that will result in the area under the spectrum being the same as all other spectra. The factor that is applied is computed such that the resulting average of the spectrum values is the values given by the OUTAVE parameter.
OUTAVE	Specifies the spectrum average to be produced by the equal area normalization option when EANORM=YES is specified. This parameter is not used when EANORM=NO is specified.
OTYPE	Output pixel data type. Permitted values are: NULL = output type is same as input file pixel type 1 = 8-bit (integer with type conversion parameters) 2 = 16-bit (integer with type conversion parameters) 3 = 32-bit (floating point) When processed data are being written back into the input file, the output pixel type must be the same as the existing pixel type in the input file.
ORANGE	Output pixel data range. If ORANGE is NULL, then the CORE_BASE and CORE_MULTIPLIER in the output file will be set to represent the same range of data as the input file. If OTYPE=1 (8-bit) or OTYPE=2 (16-bit), then the CORE_BASE and CORE_MULTIPLIER in the output file will be set to values that allow representing the specified range of output values. Output values outside this range will be stored as a special "representation saturation" value. The ORANGE parameter is ignored if OTYPE=3 (32-bit) since the CORE_BASE and CORE_MULTIPLIER are not applicable to floating point pixel values. **NOTE** For a more detailed explanation of ORANGE, tutor the orange.pdf.
USERNOTE	Comment from the user. This will be recorded in the ISIS session log file and also in the History entry that is put into the History object of the output file.