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Dear astro-wisers,
<p>In the coming two quarters of 2004, the main
3 items of OAC
<br>activity will be:
<p>I) Variability tool.
<br>After a few internal discussions at the beginning of this year,
<br>it was clear that the local community was much more interested to
<br>have a tool for image subtraction, which could be
used for different
<br>projects in different time-scale domains.
<br>Hence we started a phase of tests on two independent existing
<br>packages, both based on the Alard (1999, A&A
343, 10) method.
<br>The two packages are: ISIS (Alard) and ISS (Wozniak), both
are free.
<br>After some tests on WFI images, we decided for the second one,
which
<br>is better written and has more documentation.
<br>Therefeore, we defined to modify the software
of Wozniak, in order
<br>to improve a few items that were not satisfactory for our
purposes,
<br>and in order to render it compatible with the AW platform.
<br>1) Implement masks on each single image.
<br>2) Define different classes of variables.
<br>3) WCS: move from x,y to AR,DEC
<br>4) Improve selection of objects for PSF construction.
<br>5) Absolute photometry and relative amplitudes (??).
<br>6) Times from headers.
<br>7) Stamps of variable candidates.
<br>8) Parallelization.
<br>9) Python interface and AW compatibility.
<br>Currently items 1), 4) and 7) were done and Alfredo is
working
<br>on item 3).
<p>Schedule: we plan to have a preliminary version of the modified
software
<br>by the end of 3d quarter
<p>II) QC.
<br>OAC is participating in the second phase of QC of calibration
frames
<br>(BIAS, FF and fringing).
<br>Concerning BIAS and FF, the goal is to define how to apply
the tools
<br>written last year, which are already in the pipeline but
not used yet.
<br>Concerning fringing QC, we are currently making tests and
we just
<br>made a very preliminary proposal on how to vertify
the quality of
<br>the fringing correction. The next step, after some
discussions with
<br>the partners, will be to write the code for fringing QC.
<p>Moreover OAC participates also on the other three groups
on QC:
<br>- Astrometry;
<br>- Photometric calibration;
<br>- Overall pipeline.
<p>III) Pipeline validation.
<br>The report written by us recently on the
first validation of the AW pipeline
<br>has revealed a few problems and produced some discussions
on how
<br>to solve these problems and how to improve the output products.
<br>After this phase will be concluded and these problems solved,
we plan
<br>to continue with a second series of tests, applying the AW pipeline
in the case of
<br> more critical situations (e.g. very poor vs
very crowded fields,
<br>variable background fields, etc. ...) in order to
check how the pipeline
<br>behaves in critical conditions.
<br>
<p>Kind regards,
<br>
Roberto
<pre>
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Dr. Roberto Silvotti
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INAF (Istituto Nazionale di AstroFisica)
Osservatorio Astronomico di Capodimonte
via Moiariello 16, I-80131 Napoli, Italy
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tel/fax: +39-081-5575583/456710
e-mail: silvotti@na.astro.it
web: <A HREF="http://www.na.astro.it/~silvotti">http://www.na.astro.it/~silvotti</A>
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