vlonorm Documentation

vlonorm - Variable length offset normalization of each spectrum
VLONORM makes a multiplicative adjustment to each set of bands based on
a user specified offset so that the area under each individual set of
offset bands of the spectrum (equivalently, the mean of nonnull DN's) is
the same.   Note that if NORMOFFS=1, then this is basically the same
function EANORM performs, with a more limited amount of performance.

For each set of offset bands in each spectrum the average is computed
and applied to only those bands included in the normalization based on
the specified offset.  Occurrances of all NULL values or a sum of 0.0,
and the set of bands are nulled.  Hence, some parts of a each spectra
may result in NULL spectral values with each offset.

Occurrances of special pixel values in the normalization calculation
will not be included in the average.  Hence, should no valid points
occur in the multiplicative factor, the entire spectrum is NULLed.  Note
also that any occurrance of special pixel values in the spectrum during
the application of the computed multiplicative factor will be propagated
to the output cube unchanged.

The user may optionally choose to place the computed spectral average
for each spectrum in a new core plane and/or in a new backplane.  The
value that is stored in the new core plane will have the multiplicative
factor specified by the CORFACT TAE parameter applied prior to insertion
in the output core plane.  Values for the new core plane must be added
to the BAND_BIN keywords.  For the BAND_BIN_CENTER keyword, the
difference between the last two bands is added to the last value and
appended to the keyword.  For all other real keywords, 0.0 is appended
for the new core plane.  For integer keywords, 0 is appended.  If the
user chooses to have the value placed in a backplane, the true (no
scaling applied) spectral average is stored.  Note that the name of this
new suffix supplied by the user via the SFXNAM TAE parameter must be
unique to other existing backplane names in the input cube!

Programmer:  Kris Becker, 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

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

--

Output min/max data range

--

The band offset used to group
averaged bands

NONE

Additive constant applied to
each spectrum prior to any
calculations

0.0

Apply entire spectrum average to
each band

"NO"

Output spectrum average

1.0

Store average in new core plane

"YES"

Multiplicative factor to be
applied to stored core average

1.0

Store average in new backplane

"NO"

Name of new backplane suffix to
store spectral average

--

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.
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.
NORMOFFS	The band offset used to group points along the spectrum to compute each average. Note that this value also specifies the number of iterations on EACH spectrum. For example, if NORMOFFS=24, then band grouping is every 24th spectral point and the bands included on the first iteration is (1,25,49,...). There will be 24 iterations on each spectrum to compute a unique average for each group of bands.
ADD	An additive constant supplied to the user that is applied to each band in the spectrum prior to any calculations performed.
SPECAVE	This parameter allows the user to apply the average of each spectrum to the normalization, thus preserving the brightness of each band. If SPECAVE=NO, then the STOCOR and STOBCK options will have no relevence to the output cube and are ignored.
OUTAVE	Value to which the average of nonnull elements of each spectrum will be scaled on output.
STOCOR	Flag that specifies the computed average of bands selected by the band normalization subcube specification is to be placed in a new core band in the output cube. If SPECAVE=NO, this option is ignored and no extra core plane is produced.
CORFACT	Multiplicative factor to be applied to the computed average of the selected normilization bands that is placed in the new core plane when STOCOR=YES.
STOBCK	Flag that specifies the computed average of bands selected by the band normalization subcube specification is to be placed in a new backplane in the output cube. If SPECAVE=NO, this option is ignored and no extra core plane is produced.
SFXNAM	The name of the new backplane created to store the computed average of the selected normalization bands when STOBCK=YES. If STOBCK=NO, this parameter is ignored.
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.