[News] Some issues
Dr. Mark Neeser
neeser at usm.uni-muenchen.de
Thu Sep 11 14:58:19 CEST 2003
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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> >News at astro-wise.org
> >http://listman.astro-wise.org/mailman/listinfo/news
> >
> >
>
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