From: <Tasso.Tzioumis_at_email.protected>
Date: Fri, 2 Jun 2006 11:11:19 +1000

Hi everyone,

Thanks to Jim for re-opening this debate and to Steven for his
contribution.

I do agree with both of you and it has been a bug-bear and an
embarrassment that we have not been doing better in this. And this is
good opportunity to get something underway.

Can we discuss this over a telecon? I was hoping to have a Post-
observing telecon, perhaps next week? I'll send out a separate email
to find a time.

I'd like to add a couple of points asa a clarification:

We have gone backwards a bit recently in the quality of the logfiles,
especially at Mopra and ATCA. This is mainly due to the transition of
observing programs to new computers and Unix. Hopefully these will
settle down very soon.

However, for this transition period (last Nov, Mar and May) we are
likely to see one-off problems with logfiles etc and we'd need to
deal with them in some manner. I'm sure we will find ways around
these problems but it will require some extra effort and a little
frustration. Apologies about that.

Thanks everybody for their willingness to help in this process.

Cheers
Tasso

On 02/06/2006, at 10:02 AM, Steven Tingay wrote:

>Hi Jim,
>
>I, and others, have been agitating for changes to the calibration
>procedures for the LBA, to address issues such as you have brought
>up -
>for a long time. I think we all recognise that this needs to
>happen. The
>question is, as usual, who has the time?
>
>At the ATCA and Parkes, the method by which the Tsys information is
>logged
>makes it a pain for the observers to extract the AIPS-readable
>tables for
>every experiment. It is a significant adition to the workload for the
>observers and I don't think it is a task that they should be
>responsible
>for. Historically, calibration has been the responsibility of the
>PI - we
>have all struggled with it from time to time but generally it works
>ok.
>
>However, our calibration has gone backwards recently, for a number of
>reasons. In addition, Leith's observations seem to have sufffered
>from an
>additional specific problem at the ATCA in March. I suspect that
>it may
>have something to do with changes to CATIE, but I am not sure.
>Anyway,
>the calibration of this experiment is going to be more problematic
>than
>usual. I'll note that this happens from time to time at all
>antennas -
>when Tsys information is not recorded for some reason. I'm sorry
>that I
>don't have time to go into this myself in detail at the moment.
>
>We need someone to take a leadership role on calibration. Someone
>from
>the ATNF, I would argue. We need some reasonably efficient and
>automated
>way to compile all the calibration data, at least from the ATCA,
>Mopra,
>and Parkes. Hobart, Ceduna, and Tid seem to have good systems in
>place.
>
>Lots of ideas have been thrown around over the years, and a few
>implemented. We need to take the next step.
>
>With regard to the shift of correlation to Swinburne, we are
>entering into
>a contract with the ATNF. This document sets out the deliverables
>(i.e.
>what the ATNF get and what is delivered to PIs as post-correlation
>products) and performance criteria. It is all documented. I can
>confirm
>that we will not be responsible for any aspect of calibration,
>other than
>advising the PI what Tsys in Jy has been applied at the
>correlator. This
>reflects what is currently done at the S2 correlator.
>
>I would love to be able to attach Tsys and gain tables to the
>data. It
>would be easy with the software correlator. If we had a robust
>scheme to
>produce good calibration files in some format, then we could work on
>including them with the correlated output. This will not be a part
>of our
>contracted obligations, however.
>
>In fact, I would make this suggestion. If someone can determine a
>scheme
>to automatically collate the Tsys files in their native formats,
>from each
>antenna, on the ATNF ftp site, the functionallity of logs2keyin
>could be
>incorporated into a pre-correlation step at Swinburne. This would
>remove
>the problems of multiple versions of logs2keyin floating around and
>would
>consolidate the process in one place.
>
>I'd be willing to work on this from our end, if someone can be
>identified
>on the ATNF end to put some time into this.
>
>Cheers, Steven
>
>##=====================================================##
>Dr Steven Tingay stingay_at_astro.<!--nospam-->swin.edu.au
>Swinburne SKA Project Leader
>Associate Professor
>
>Centre for Astrophysics and Supercomputing
>Swinburne University of Technology
>Mail No H39
>P.O. Box 218, Hawthorn, Vic. 3122, Australia
>
>ph: +61 3 9214 8758
>fax: +61 3 9214 8797
>
>http://astronomy.swin.edu.au/ska
>##=====================================================##
>
>On Fri, 2 Jun 2006, Jim Lovell wrote:
>
>>Dear VLBIers,
>>
>>I'd like to make a request regarding calibration (Tsys and flag)
>>files. Is it
>>possible for observatories to provide AIPS-readable input files
>>along with
>>logs following the experiment? I know that UTas and Tid do this
>>already but it
>>doesn't happen at Mopra or the ATCA and Parkes files don't seem to
>>end up on
>>the FTP site automatically.
>>
>>If these files are prepared straight after the experiment by the
>>observer then
>>it makes it a heck of a lot easier for the PI. Leith and I have been
>>struggling to interpret the ATCA and Mopra Tsys logs which seem to
>>be either
>>non-standard or to have changed recently because logs2keyin
>>produces strange
>>output. Working out what happened and how to get what we need is
>>impossible
>>without hassling the people who made the observations in the first
>>place. So
>>it seems better all round for the files to be produced by the
>>observers.
>>
>>And while I'm sticking my neck out, could I make one more
>>suggestion? With the
>>move of correlation to Swinburne, will there be some sort of LBA
>>operations
>>document written that describes who is responsible for what? If
>>so, could this
>>document include a description of what the PI will get post-
>>correlation? I
>>would hope that they would at least get all the calibration files
>>with their
>>data.
>>
>>Thanks,
>>Jim
>>
>>--
>>Dr Jim Lovell,
>>Jim.Lovell_at_csiro.<!--nospam-->au
>>CSIRO Australia Telescope National Facility Ph: (02) 6125
>>6715
>>c/o RSAA, Mt Stromlo Observatory, Fax: (02) 6125
>>0260
>>Cotter Road, Weston ACT 2611 Mobile: 0412
>>127364
>>Australia http://www.atnf.csiro.au/people/
>>Jim.Lovell
>>At Tidbinbilla Ph (02) 6201 7842 (RA Lab), x7800 (switch), x7940
>>(shift)
>>
>>
>>

--------------------------------------------------------------------
Tasso Tzioumis, Australia Telescope National Facility, CSIRO
Location: Cnr Pembroke & Vimiera Rds, Marsfield, NSW, 2122, AUSTRALIA
Post: PO Box 76, Epping, NSW 1710, AUSTRALIA
Phone: +61 2 9372 4350 Fax: +61 2 9372 4450 or 4310
Email: Tasso.Tzioumis_at_csiro.<!--nospam-->au
URL: http://www.atnf.csiro.au/~atzioumi/
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Received on 2006-06-02 11:11:45