thm2isis Documentation

thm2isis - Convert THEMIS IR/VIS images to ISIS for lev processing
OVERVIEW

This procedure converts PDS-formatted THEMIS IR and THEMIS VIS
files to ISIS-formatted cube files and initializes the geometric
information in the labels of the output file so that the ISIS
cube can be processed in the ISIS lev system. If the input PDS
file is a single-band file, then the output ISIS cube will have
a single band. If the input PDS file is a multi-banded file, then
the output ISIS cube will have multiple bands.

The input PDS-formatted file can optionally be compressed by
using the gzip program.  If so, it will be uncompressed (into
a temporary file) by running gunzip.

The procedure can be used to process a single input file
(specified by the FROM parameter) or a list of files (specified
by the FROMLIST parameter).

The TIME and TIMELIST parameters allow the user to apply a
correction to the spacecraft time for the observation to
correct for the interminate time delay between the requested
time and the time of the actual start of the observation.


PROCESSING WITHOUT USE OF TAE

This procedure provides an interactive interface to the PERL
scripts that perform the work involved in converting the PDS
files to ISIS cubes. The PERL scripts can also be run
standalone from the command line which makes them ideal for use
in web.html applications. There are two PERL scripts available
for converting PDS-formatted THEMIS IR/VIS files to ISIS cubes:
thm2isis.pl, thm2isis_batch.pl

The thm2isis.pl script will process a single file for each
execution of the script. The thm2isis_batch.pl script allows you
to process a list of files for each execution of the script.

The syntax for processing a single file is as follows:

thm2isis.pl from [to] [transtab] [targdef] [kernlst]
  [instpars] [lonsys] [latsys] [time]

The syntax for processing a list of files is as follows:

thm2isis_batch.pl fromlist [transtab] [targdef] [kernlst]
  [instpars] [lonsys] [latsys] [time] [timelist]

All the parameters in square brackets [] above are optional. The
parameters in square brackets can be used to specify how the output
cube is created. If a parameter is specified on the command line,
then all of the parameters preceding it must also be specified.
If you want the default of a parameter to be used, then two dashes "--"
can be used to specify this on the command line.  For example, the
following command can be used to process a single file
(called thm01.pds) and set the longitude system (lonsys) to 180.

thm2isis.pl thm01.pds -- -- -- -- -- 180

In the command above, the user wanted to specify a non-default
longitude system of 180. However, the user wants to use the default
for the remaining parameters. The double dash "--" is used as a
place marker so that the script knows which value on the command
line applies to which parameter in the script. Notice that none of
the parameters that occur after the longitude system had to be set
to "--" because the user is letting everything else use the default
values.


PROCESSING AND ERROR LOGGING

If an error occurs during processing, then thm2isis.err will be
created which will contain some error-related information. The session
log file (print.prt unless the ISIS_LOG_FILE environment variable has
been set) will contain a complete history of the processing as well as
additional error information.

Programmer:  Janet Barrett, U.S.G.S., Flagstaff, 23 Oct 2003

Input PDS filename
 (file extension required)

--

List of input PDS filenames

--

Output filename
 (default extension is .cub)

--

Name of translation
table file

--

File containing target
defintions

--

File containing kernel list

--

File containing instrument
parameters

--

Longitude system
(180,360)

360

Latitude system
(OCENTRIC,OGRAPHIC)

OCENTRIC

Adjustment to spacecraft clock
time (seconds)

0.0

List of input time offsets

--

ADDITIONAL NOTES:

Parm	Description
FROM	This is a PDS-formatted THEMIS IR or VIS file. The file extension must be included with the filename. The input file can be 8, 16, or 32 bit. The output file will be the same data type as the input file. The input PDS-formatted file can optionally be compressed by using the gzip program. If so, it will be uncompressed (into a temporary file) by running gunzip. In this case, the original compressed input file will be unchanged. If FROM is specified, then the FROMLIST parameter must be specified as the Null TAE parameter value.
FROMLIST	This specifies a file that contains a list of PDS-formatted files to be processed. The input list must be a single column file that contains one input PDS file name per line. The file extension of the filenames in the list must be included. The input files can be 8, 16, or 32 bit. The output files will be the same data type as the input files. If FROMLIST is specified, then the FROM parameter must be specified as the Null TAE parameter value. The output filenames will automatically be created by using the 'root' input name (without extension) with ".lev1.cub" appended.
TO	If a single file is processed using the FROM parameter, then this parameter can be used to name the output file. If the file extension is omitted, then ".cub" will be assumed. This parameter is ignored when a FROMLIST is entered. If the FROMLIST option is used or if this parameter is left blank, then the output filename will default to be the 'root' name of the input file (without extension) with ".lev1.cub" appended.
TRANSTAB	This is the translation table to be used by pds2isis for translating PDS labels keywords to ISIS label keywords. The default is to use the latest version of the thm2isis_translation.def file in $ISISM01DATA.
TARGDEF	This is the target definition file to be used by levinit for acquiring information specific to Mars. The default is to use $ISISDATA/targets/mars.def.# where # specifies the latest version of the file available.
KERNLST	This is the kernel list file to be used by levinit for acquiring the names and locations of SPICE kernels for the THEMIS images.
INSTPARS	This is the instrument parameters file to be used by levinit for obtaining instrument specific information about the THEMIS IR/VIS instruments.
LONSYS	This is the longitude system that will be used when the output image is processed by other ISIS programs. The valid values are 180 and 360. The default is 360 which implies that longitudes will be in the range 0 to 360 for the image. A longitude system of 180 implies that longitudes will be in the range -180 to 180 for the image.
LATSYS	This is the latitude system that will be used when the output image is processed by other ISIS programs. The valid values are OGRAPHIC and OCENTRIC. The default is OCENTRIC.
TIME	This parameter can be used to adjust the spacecraft clock time. The time offset should be specified in seconds (fractional seconds allowed). This offset will be added to the spacecraft clock time that is recorded in the ORIGINAL_SPACECRAFT_CLOCK_COUNT keyword in the ISIS_INSTRUMENT Group in the output file. (This is the time that is used by the ISIS geometry programs.) This allows the user to correct for the indeterminate time delay between the requested start of the observation and the actual time that it started. (A copy of the uncorrected time from the input file will be put into the SPACECRAFT_CLOCK_START_COUNT keyword in the THEMIS_KEYWORDS Group.) If TIMELIST and FROMLIST are both specified, then this parameter will be ignored. If a FROMLIST is provided and TIMELIST is not specified, then the TIME will be applied to every image in FROMLIST. If FROM is specified, then this parameter will be used even if a TIMELIST is specified.
TIMELIST	The TIMELIST is a file that contains a list of time adjustments to be applied to the images in the FROMLIST. The time offset should be specified in seconds (fractional seconds allowed). This offset will be added to the spacecraft clock time before processing of the input image is done. This parameter is only valid if the FROMLIST parameter is used. It will be ignored if the FROM parameter is used. TIMELIST must be a single column file that contains one time offset value per line. There should be the same number of entries in both the FROMLIST and the TIMELIST files. If an image does not need a time adjustment, then put 0.0 into the TIMELIST for that image. If TIMELIST is specified, then the TIME parameter is ignored. If a FROMLIST is specified without a TIMELIST, then the value in TIME will be applied to every image in FROMLIST.