[News] Some issues
Luiz DaCosta
ldacosta at eso.org
Thu Sep 11 15:16:08 CEST 2003
Mark
That would be great, and asap as your people are back let us know
to schedule
Luiz
Dr. Mark Neeser wrote:
>Hi Luiz,
>
>yes, I would be interested. At the moment, Jan has gone on
>vacation, so I would only suggest that we get together sometime
>after Sept. 26.
>
>Cheers,
>
>Mark
>
>
>
>On Thu, 11 Sep 2003, Luiz DaCosta wrote:
>
>
>
>>Mark
>>
>>I wonder if you would be interested in coming to ESO and getting a demo
>>from B. Vandame using the C-library only for the same data which we
>>could ftp
>>to ESO - I would be very interested
>>
>>Luiz
>>
>>Dr. Mark Neeser wrote:
>>
>>
>>
>>>Hello All,
>>>
>>>As a test of data reduction routines (astro-wise vs. Bonn pipeline vs.
>>>IRAF) we have immersed ourselves (primarily Jan Snigula and
>>>Yuliana Goranova) in the astro-wise pipeline using our WFI data.
>>>
>>>Here some results/comments:
>>>
>>>- Dataset used for testing: WiFI- images taken over 6 nights
>>> (approx. 50GB).
>>>
>>> Time for testreduction: approx. 1 week (most of the delays were caused
>>> by unannounced pipeline changes occurring during the reduction.
>>>
>>>Details:
>>>
>>>- COSMICFILTER:
>>> We tried to implement our cosmic filtering routine (cosmicfits from
>>> Claus Goessl) in the pipeline. This attempt failed, due to the
>>> current handling of bad columns/pixels in the images and the
>>> existance of negative pixel values. The latter problem can be
>>> circumvented in the program call, but the bad columns/pixels would
>>> need to be replaced (PRIOR to executing our cosmic filter routine) with
>>> a well defined NaN value, e.g. 0. Essentially, our cosmic filter
>>> routine treats the bad columns as cosmic rays and spends an inordinate
>>> amount of time trying to detect/correct them. It would be easy to
>>> mask these as NaN's prior to running "cosmicfits".
>>>
>>>- BAD COLUMNS:
>>> Bad colums in general must be taken care of at an earlier stage of
>>> the pipeline than currently implemented (see example ps
>>> file). This was already discussed by Mark and Roeland.
>>>
>>>- SWARP:
>>> The pipeline currently uses a beta version of Swarp (swarp 2.0b),
>>> that fails to create usable weight images. Reasonable weight
>>> images are essential for obtaining a fast run-time with cosmicfits,
>>> and are crucial when the frames on which cosmic rays are detected
>>> have strong intensity slopes.
>>>
>>>- UPDATES:
>>> Unannounced pipeline changes that change object definitions, require
>>> changes to the database, that can be time consuming, given the fact,
>>> that we have to figure out the changes from the code, and guess
>>> the needed Database changes. Usually Danny sends out an e-mail
>>> explaining the required changes (usually after talking with Roeland
>>> about the changes in the pipeline), but these e-mail come about 2
>>> days after the changes, causing severe interruptions.
>>>
>>> Suggestion: Create a stable branch of the pipeline in the CVS with
>>> weekly? updates from a development branch, and the changes in these
>>> updates should be discussed with the DBAs before, so that updates to
>>> the pipeline cause as few interruptions as possible.
>>>
>>>
>>>
>>>- TESTS:
>>>
>>> - Bias:
>>>
>>> Subtracting resulting masterbias from its raw input frames
>>>
>>> rawbias file name median stddev average stddev
>>> seWFI.2003-01-05T20C54C42.283_4.fits -0.199997 18.876 -0.244914 18.8759
>>> seWFI.2003-01-05T20C55C44.983_4.fits -0.100006 18.9255 -0.161555 18.9254
>>> seWFI.2003-01-05T20C56C42.354_4.fits 0.100006 18.89 0.00905352 18.8897
>>> seWFI.2003-01-05T20C57C39.851_4.fits 0.100006 18.9164 -0.00907611 18.916
>>> seWFI.2003-01-05T20C58C34.232_4.fits 0 18.8818 -0.0418041 18.8818
>>> seWFI.2003-01-05T20C59C33.157_4.fits 0 18.881 -0.0651421 18.8809
>>> seWFI.2003-01-05T21C00C32.066_4.fits 0 18.8516 -0.0559038 18.8515
>>> seWFI.2003-01-05T21C01C33.362_4.fits 0 18.888 -0.0407198 18.888
>>> seWFI.2003-01-05T21C02C30.338_4.fits 0.100006 18.8894 0.000104276 18.8891
>>> seWFI.2003-01-05T21C03C29.919_4.fits 0.100006 18.9252 0.0489991 18.9252
>>>
>>> (Is there a numerical round-off occurring in the median computation?).
>>>
>>> - DomeFlat:
>>>
>>> Flatfielding biassubtracted raw domeflatframes using the processed
>>> domeflat. ( SEM = std. error)
>>>
>>> flatfielded raw flatfield filename median stddev average stddev
>>> dseWFI.2003-01-06T21C59C26.278_4.fits 17778.8 90.3731 17778.1 90.3702
>>> dseWFI.2003-01-06T22C00C53.969_4.fits 19056.3 94.5017 19055.6 94.4991
>>> dseWFI.2003-01-06T22C02C15.050_4.fits 19074.4 94.4472 19073.4 94.4418
>>>
>>> - TwilightFlats:
>>>
>>> Flatfielding biassubtracted raw twilightflatframes using the processed
>>> twilightflat. ( SEM = std. error)
>>>
>>> flatfielded raw flatfield filename median stddev average stddev
>>> dseWFI.2003-01-04T00C17C43.159_4.fits 17885.3 122.664 17886 122.662
>>> dseWFI.2003-01-04T00C19C14.085_4.fits 17161.4 134.724 17161.9 134.723
>>> dseWFI.2003-01-04T00C21C01.056_4.fits 16581.6 151.299 16582.4 151.297
>>>
>>> - Astrometry:
>>> From visual inspection of stars from the USNO catalog overplotted
>>> on the image, the astrometric solution determined by the pipeline
>>> seems to be very accurate even out to the edges.
>>>
>>> Hard numbers:
>>> mean position differences in arcsec:
>>> RA DEC
>>> -0.0002 0.0001
>>>
>>> mean sigma of the position differences in arcsec:
>>> RA DEC
>>> 0.4199 0.4021
>>>
>>>
>>>
>>>
>>>Cheers,
>>>
>>>
>>>Mark
>>>
>>>
>>>
>>>
>>>
>>>=====================================================
>>>Dr. Mark J. Neeser
>>>
>>>Institute for Astronomy and Astrophysics, _/ _/ _/ _/_/ _/
>>>Ludwig-Maximilians-Universitaet Muenchen _/ _/ _/_/ _/ _/ _/ _/
>>> _/ _/ _/ _/ _/ _/ _/_/
>>>Scheinerstrasse 1, _/ _/ _/_/ _/ _/
>>>D-81679 Muenchen, Germany
>>>
>>>Tel: +49-89-2180-5995
>>>Fax: +49-89-2180-6003
>>>
>>>email: neeser at usm.uni-muenchen.de
>>>
>>>
>>>_______________________________________________
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>>>
>>>
>>>
>>>
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