poa_preproc

poa_preproc_fos

stpoa.poa_fos

poa_preproc_fos

NAME · USAGE · DESCRIPTION_ · PARAMETERS · EXAMPLES_ · NOTES
BUGS · REFERENCES · HELP · SEE_ALSO

NAME

poa_preproc_fos -- Pre-process Faint Object Spectrograph (FOS) data in preparation for calibration task poa_calfos.

DESCRIPTION

The poa_preproc_fos task is the pre-processor required to prepair raw data from the HST archive for processing with the poa_calfos pipeline. The pre-processor performs the following steps:

  1) Checks to see if the FOS dataset falls into the POA processing
     criteria;  if yes, then pre-processing is commenced,  if not, 
     then the pre-processing is aborted with a message to the user 
     that the POA FOS data criteria were not met.  POA processing 
     criteria for FOS data are:

	Detector:  BLUE
	Grndmode:  SPECTROSCOPY, RAPID-READOUT, IMAGE
	Fgwa_id:   H13, H19, H27, H40, H57, L15, L65           
	Aper_id:   A-1, A-2, A-3, A-4, B-1, B-2, B-3, B-4
 
     If the data match the POA processing criteria, then steps 2-6
     are performed on the input root.*h headers.

  2) Sets the zero-point offset correction header keyword (OFF_CORR) 
     to a value of 'PERFORM'.

  3) Turns off the scattered light correction header keyword  
     (SCT_CORR) by setting it to a value of 'OMIT'.  

  4) Sets the value of the wavelength calibration header keyword
     (CCS6) to the new POA location and filename:
            CCS6=pwav$/l611655ty.cy6  (for pre-costar data)
            CCS6=pwav$/l611655oy.cy6  (for post-costar data)

  5) Extracts the names of the flat field correction header keywords
     (FL1HFILE, FL2HFILE);  checks to see if there is an equivalent
     flatfield which has been redone with a POA correction;  if yes,
     then the location and new flat field(s) is written to the
     header;  if no, then the flat field keyword(s) remain the same.
            FL1HFILE=pref$/$l7m1413ly.r1h  (y3ck040bt.d0h example)

  6) Adds 10 new header keywords to the raw headers.  These 
     contain new reference files which are needed for the POA
     pipeline processing.  These keywords are:
            CYCCSFR=ref$l5u1739ay.cyf

            CYCCSER1=ref$l5u1623cy.cye
            CYCCSER2=ref$l5u16246y.cye
            CYCCSER3=ref$l5u1624ay.cye
            CYCCSER4=ref$l5u1624ey.cye
            CYCCSER5=ref$l5u1624iy.cye
            CYCCSER6=ref$l5u1624ny.cye
            CYCCSER7=ref$l5u1624qy.cye
            CYCCSER8=ref$l5u16250y.cye
            CYCCSER9=ref$l5u16255y.cye

NOTE: The current version of the POA FOS software (v1.2.1 Nov 2001), has the POA reference files internal to the STPOA package. Therefore, reference files locations will be set to "ref$", "pref$" and "pwav$"; these variables are set by opening the stpoa.poa_fos packages. However, these same POA ref files are likely to be ingested into the STScI CDBS system, later to be available via the standard "yref$" and "ytab$" locations. The internal_ref parameter (described below) allows one to set the headers to point to the internal STPOA reference files, or to those same files in CDBS (internal_ref parameter set to "no", which is the same as using external reference files).

The POA FOS tools rely on the STSDAS and TABLES packages; therefore, we advise that one adds the following to their IRAF login.cl file (before the keep statement):

	tables
	stsdas
	hst_calib
	fos
        ctools
	stpoa
	poa_fos

If these packages are not loaded via the login.cl file, then one must open them on the command line prior to running the POA FOS tools.

The pre-processor will write messages to STDOUT, depending on what it finds in the FOS header, and what aspect of the pre-processing will be performed, if at all. If a FOS dataset does not match the POA criteria (listed above, and to STDOUT), then a WARNING will indicate that it cannot continue processing using poa_calfos. One should use calfos to process data that do not fit the POA criteria.

Once the pre-processor has finished successfully, one can run the task poa_calfos on the dataset.

The tool processfos is also provided to ease FOS data processing. It runs the pre-processor and the pipeline, checking to make sure the data fit the POA processing criteria. If the data do not match the POA criteria, the tool will run calfos on the data instead. This tool also allows one to run on a list of FOS datasets, running the pre-processor and pipeline for all the rootnames in the list. Please see the processfos for more details as well as instructions on how to run on a list.

Also, please see the poa_calfos help file for more details on the POA FOS re-calibration processing steps.

PARAMETERS

input [string]: The rootname of the input FOS observation data set.

(internal_ref = yes) [boolean]: The POA reference files are added to the raw headers using the pre-processor; the stpoa internal reference files are used by default (internal_ref = yes). However, the user also has the option to use external CDBS POA calibration reference files, by setting this parameter to "no". It is up to the user to check that the stpoa reference files are also available in CDBS. If the pre-processor does not find the reference files in CDBS, it will issue a warning and set the reference files to the internal files. Unless stated otherwise in the release notes or on the POA web pages, the FOS POA calibration reference files internal to stpoa should be identical to the external CDBS files. CDBS ingestion of the FOS POA ref files can take some time; therefore, these files are always made available internally to match a given release, while CDBS can only be updated after a given release.

(force_poa = no) [boolean]: Prior to processing, the data are checked to see if the POA pre-processor has already been run; if not, then this tool will run the pre-processor; if yes, then this tool will exit, stating that one can run the pipeline directly or force re-pre-processing. This option is for the unusual case of needing to re-run the POA FOS pre-processor. If the FOS data have already been pre-processed, then it is unlikely that one would want to re-run the pre-processor. Perhaps in the event that the header has been manually changed; the user may want to force the POA pre-processor to be re-run. If so, then set this option to yes. This option has built into the system mostly for the POA project, for testing the POA criteria. If the poa_calfos pipeline is updated with further improvements (say for other FOS modes) one can issue the pre-processor to accept a FOS dataset even if it does not yet fall into the POA processing criteria.

EXAMPLES

1. Run the pre-processor and perform calibration for observation y0k4510dt. All data files for this observation are in the directory poa_spec$ and are copied to the current working directory. Output files are to have the same root name as the input files.


  st> copy poa_spec$y0k4510dt.* .
  st> poa_preproc_fos y0k4510dt
  st> poa_calfos y0k4510dt ""

2. Pre-process and calibrate the observation y3ee2804t (in one step) and produce output files with a root name of test186 in the subdirectory temp.


  st> copy poa_spec$y3ee2804t.* .
  st> mkdir temp
  st> processfos y3ee2804t temp/test186

3. Pre-process and calibrate a list of observations (in one step), using an ascii text file of the root names to be processed; output file rootnames will be the same as the input. The sample data are in the poa_spec$ directory; as is the sample list file, which is called y0.list. Please see the processfos help file for more information on processing a list of FOS rootnames.


  st> copy poa_spec$y0cw0109t.* .
  st> copy poa_spec$y0cw010it.* .
  st> copy poa_spec$y0cw0110t.* .
  st> copy poa_spec$y0k4510dt.* .
  st> copy poa_spec$y0ue0103t.* .
  st> copy poa_spec$y0.list .
  st> processfos y0.list ""

NOTES

Running poa_preproc_fos on data which do not match the POA criteria (listed in the DESCRIPTION section), will issue a WARNING to STDOUT, telling the user that there is no POA correction for that particular dataset. Unfortunately there is no POA correction for FOS RED datasets nor for some modes of FOS BLUE data. Instead of running the POA pre-processor or pipeline poa_calfos, one should run the current version of calfos on these data instead. The result will be the standard set of calfos output products, with no POA changes in the calibration.

Once the POA pre-processor has been run on the FOS data, one should not use calfos on these pre-processed data. The wavelength calibration files and the flat field files have been changed in the header to point to the POA version; calfos should not use these files for processing. Therefore, we highly recommend that one does not use calfos on POA pre-processed data. Keep a copy of the original non-pre-processed data, if you want to run calfos.

In the unusual case where one would like to reset the header back to the way it was before the POA pre-processing, one can use hedit to manually change the header values. Use the POA pre-processor STDOUT messages as the source of what the original values were, prior to pre-processing the data files.

An example for changing header keyword values after the pre-processor has been run, is as follows. If the following changes took place during the pre-processing:


   OFF_CORR=OMIT   ===>   OFF_CORR=PERFORM
   SCT_CORR=PERFORM   ===>   SCT_CORR=OMIT
   FL1HFILE=yref$i1k1220cy.r1h   ===>    FL1HFILE=pref$l7m1413ly.r1h
   FL2HFILE=yref$N/A   ===>    FL2HFILE=yref$N/A
   CCS6=ytab$e5v11576y.cy6   ===>   CCS6=pwav$l611655oy.cy6

The user can change the values back to the original values:

   st> hedit root.*h OFF_CORR "OMIT" verify- update+
   st> hedit root.*h SCT_CORR "PERFORM" verify- update+
   st> hedit root.*h FL1HFILE "yref$i1k1220cy.r1h" verify- update+
   st> hedit root.*h CCS6 "ytab$e5v11576y.cy6" verify- update+

Once the header edits the done, one should not run either the poa_preproc_fos or the processfos tasks, since they will overwrite the changes which have just been made. The only reason to set the header back to the original values, is to be able to run calfos on these data. The POA pipeline will not run on data which have not been POA pre-processed.

BUGS

REFERENCES

References to the Post Operational Archive system for HST data can be found on:

      "http://www.stecf.org/poa"

HELP

For assistance using this particular task, please contact ecf-poa@eso.org, or stdesk@eso.org (see http://www.stecf.org/poa).

For assistance using this or any other tasks, please contact help@stsci.edu or call the help desk at 410-338-1082.