USGS

ISIS 2 Documentation


Isis thm2isis Documentation

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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 cgi 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

ParmDescriptionDefault
FROM
Input PDS filename
 (file extension required)
--
FROMLIST
List of input PDS filenames
--
TO
Output filename
 (default extension is .cub)
--
TRANSTAB
Name of translation
table file
--
TARGDEF
File containing target
defintions
--
KERNLST
File containing kernel list
--
INSTPARS
File containing instrument
parameters
--
LONSYS
Longitude system
(180,360)
360
LATSYS
Latitude system
(OCENTRIC,OGRAPHIC)
OCENTRIC
TIME
Adjustment to spacecraft clock
time (seconds)
0.0
TIMELIST
List of input time offsets
--

ADDITIONAL NOTES:

ParmDescription
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.

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Last updated: Mar 6 2012