specpr2isl Documentation

specpr2isl - Convert a SPECPR library to ISL format
"specpr2isl" creates an Instrument Spectral Library (ISL) file from
a SPECPR format library.  It is assumed that all the spectral entries
in the input SPECPR file have the same set of wavelengths and that
these wavelengths are contained in the first data entry in the file.
However, there are no requirements on the order of the wavelengths.

The WAVESRC parameter selects whether the wavelengths of the output file
should be the same as the input SPECPR file (WAVESRC=SPECPR) or should
be the wavelengths recorded in a table file (WAVESRC=TABLE).

When WAVESRC=SPECPR is specified, the input spectral entries are simply
transferred to the output ISL file without modification.  In this case,
any error bar data present in the SPECPR file are also written to the
output ISL file.  There are two ways that the presence of error bar
data can be indicated in the SPECPR file.  First, the error bar flag
can be set in the SPECPR spectral header.  Second, the "ititl" field of
the following SPECPR data entry can be
"errors to previous data                 ".

When WAVESRC=TABLE is specified, "specpr2isl" produces an ISL file that
contains the wavelengths specified by a TABLE file.  The TABLE file
(which is normally produced by the "bandtab" program) must contain the
following columns:
    BAND (INTEGER*4) - Original band numbers - will be recorded in the
	BAND_BIN_ORIGINAL_BAND keyword in the ISL file
    WAVELN (REAL*4) - Wavelengths (in micrometers)
    FWHM (REAL*4) - Full width at half maximum - will be recorded in
	the BAND_BIN_WIDTH keyword in the ISL file

There are two options for translating the SPECPR data to the output
wavelengths.  TRANSMOD=CONVOLUTION selects convolution using the
full width at half maximum information.  If an output wavelength is
outside the range of input wavelengths, then the output spectral value
is set to the NULL pixel value.  TRANSMOD=INTERPOLATION selects linear
interpolation.  Each output spectral value is computed using the input
spectral values at the two wavelengths that are closest to the
output wavelength.  If either one or both of these two closest input
values is not a valid value, then the output value is set to the NULL
pixel value.  If an output wavelength is outside the range of input
wavelengths, then the output spectral value is set to the NULL pixel
value.

The NAMESEL parameter allows selecting input SPECPR spectra based on
the contents of the "ititl" field of the SPECPR spectral header.  If
a NAMESEL value is specified, then only input spectra that contain
this string within the "ititl" field will be included in the output
ISL file.  This is useful for processing SPECPR files in which the
spectral entires contain "ABS REF" in the "ititl" field to distinguish
them from "feature analysis" data.  If NAMESEL is specified as the
Null TAE parameter value, then all data entries in the input file
are translated to the output file.

When a TABLE file is being used as the source of wavelengths for the
output ISL file, the INSTRUMENT_ID and INSTRUMENT_MODE_ID keywords in
the ISL file are normally set to the values of these keywords in the
TABLE file.  The INSTID and INSTMODE parameters allow the user to
specify values for these keywords that override the TABLE file values.
These also allow specifying values when the source of the output
wavelengths is the input SPECPR file rather than a TABLE file.  If
a value is not specified by an input TABLE file or a TAE parameter,
then the output keyword is set to UNKNOWN.

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

SPECPR library file name
  (no default extension)

"NimsLib"

Source of output wavelengths
  (TABLE or SPECPR)

"TABLE"

Name of TABLE file containing
  the band information
  (default extension is .tbl)

NONE

Name of the TABLE file object
  that contains band information

"TABLE"

Output ISL file name
  (default extension is .isl)

NONE

Spectrum name selection string

--

Mode for translation to new
  set of wavelengths
  (CONVOLUTION or INTERPOLATION)

"CONVOLUTION"

Number of extra entries to
  allocate in ISL

0

Instrument ID

--

Instrument mode

--

User comment

" "

ADDITIONAL NOTES:

Parm	Description
SPECFILE	Specifies the SPECPR format library to convert. There is no default file extension for this file. It is assumed that all the spectral entries in the SPECPR file have the same set of wavelengths and that these wavelengths are contained in the first data entry in the file.
WAVESRC	Specifies where to obtain the list of wavelengths for the output ISL file. If WAVESRC=SPECPR, then the output file will have the same wavelengths as the input SPECPR file. If WAVESRC=TABLE, then the TABLE file specified by the TBLFROM parameter is used as the source of the wavelengths.
TBLFROM	Name of TABLE file that contains the wavelengths, full widths at half maximum, and original band numbers to be used for the output file. This table file is normally produced by the "bandtab" program. This file is used only when WAVESRC=TABLE is specified.
OBJNAM	Name of TABLE object in the TBLFROM file that contains the BAND information that will be used to create spectra in the output ISL file. This is used only when WAVESRC=TABLE is specified.
TO	Output ISL file name. If the file extension is omitted, then ".isl" will be assumed.
NAMESEL	Specifies a string value that allows selecting data entires from the input SPECPR file. If this is specified as the Null TAE parameter value, then all input data entries are translated to the output file. If a string is specified, then only input data entries that contain this string within their "ititl" spectral header field are translated to the output file. Note that for some SPECPR files the string "ABS REF" is contained within the "ititl" field to distinguish spectral entries from "feature analysis" entries.
TRANSMOD	Specifies the mode for translating from the input SPECPR wavelengths to the output ISL wavelengths. This is used only when WAVESRC=TABLE is specified. If TRANSMOD=CONVOLUTION is specified, then convolution is used. For any output wavelengths that are outside the range of input wavelengths, the output spectral value is set to the NULL pixel value. If TRANSMOD=INTERPOLATION is specified, then output spectral values are computed by linear interpolation from the input values at the two closest wavelengths. If one or both of these input values is NULL, then the output value is set to the NULL pixel value.
XSPECS	Number of extra entries to allocate in the output ISL file. The value specified here will be added to the number of entries needed to store the input SPECPR data. This will allow the later addition of other spectra to the ISL file without the need to expand the file.
INSTID	Specifies the value of the INSTRUMENT_ID keyword in the output ISL file. If this is not specified, then the value of the INSTRUMENT_ID keyword in the input TABLE file is used (if WAVESRC=TABLE). If no value is available, then INTRUMENT_ID is set to UNKNOWN.
INSTMODE	Specifies the value of the INSTRUMENT_MODE_ID keyword in the output ISL file. If this is not specified, then the value of the INSTRUMENT_MODE_ID keyword in the input TABLE file is used (if WAVESRC=TABLE). If no value is available, then INTRUMENT_MODE_ID is set to UNKNOWN.
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.