[daip] [Fwd: Re: BB310B data]

Thu Mar 21 07:10:13 EDT 2013

Hi Amy,

thanks for looking into this. Is this only a problem of the SU table in 
AIPS, or does this mean that this was also used during correlation?

BTW, I'll be in Socorro from next week until the end of the Casa workshop.

See you soon,
Andreas

On 03/20/2013 11:19 PM, Amy Mioduszewski wrote:
> Hi Andreas,
>
> So the good news is that I replicated the problem, the bad news is that
> the error goes away if I run aips in debug mode or compile the program
> without optimization.  So this sounds like a memory issue, which are
> notoriously difficult to find.  I will continue to work on it, but do
> you know a work around?  You could either use TBOUT/TBIN to change the
> -1 to 2000 or use TABED to fix the correct columns/rows.
>
> Amy
>
> Data Analysts wrote:
>>
>>
>> ------------------------------------------------------------------------
>>
>> Subject:
>> Re: BB310B data
>> From:
>> Andreas Brunthaler <brunthal at mpifr-bonn.mpg.de>
>> Date:
>> Tue, 19 Mar 2013 13:15:00 +0100
>> To:
>> analysts at aoc.nrao.edu
>>
>> To:
>> analysts at aoc.nrao.edu
>>
>>
>> Hi Meri,
>>
>> I noticed something strange in the geodetic data. In the SU-table the
>> EPOCH is set to -1, and not 2000 as it should be. The other files are
>> ok. Any idea what happened?
>>
>> Andreas
>>
>> On 02/21/2013 10:44 PM, analysts at aoc.nrao.edu wrote:
>>> Dear PI,
>>>
>>> We have examined the data for project BB310B which observed on 28
>>> Jan. 2013.
>>> The contact person for this project was Data Analysts.
>>>
>>> Preliminary notes and information:
>>>
>>> OV: On geodedic setup, x-band appears dead, apparently the arm did
>>> not move into position.
>>> EB: On geodedic setup, S-band appears dead.
>>>
>>> 1. All observers should visit http://www.vlba.nrao.edu/astro/messages/
>>>     for important messages.
>>>
>>> 2. For possible problems and additional information which may have
>>>     affected this observation, please consult the VLBA System Monitoring
>>>     page located at the Internet URL:
>>>     http://www.vlba.nrao.edu/astro/VOBS/astronomy/vlba_sysmon.html
>>>     Select (click on) the link for the 2013 VLBA System Monitoring
>>> Calendar.
>>>     Then select (click on) the monitoring project code(s) 'DQ***'
>>>     that observed during the concurrent week for this
>>>     observation.  This will display the selected monitoring project
>>> directory
>>>     where a report summary named monitor.txt can be viewed or retrieved.
>>>     This directory also contains useful plots under reference antenna
>>>     subdirectories.
>>>
>>> 3. Access to the file server is provided to view and retrieve text
>>> and PostScript files,
>>>     This can be reached through the VLBA homepage at
>>> http://www.vlba.nrao.edu/astro/VOBS/astronomy/
>>>
>>> 4. Disk weights versus time plots have been generated for the entire
>>> time range
>>>     of your experiment. These are a measure of disk record/playback
>>> quality,
>>>     representing the fraction of valid data samples. Data with
>>> weights below
>>>     70-75% should be flagged. However, you may want to be more cautious
>>>     when dealing with non-VLBA stations.  The easiest way to estimate
>>>     the best weight threshold is by looking at the disk weights vs. time
>>>     plots generated here.  You can find the weights plots at
>>> http://www.vlba.nrao.edu/astro/VOBS/astronomy/jan13/bb310b/MARK5C/jobs/sniffer
>>>
>>>     /*wts.ps.
>>>     See
>>> http://www.vlba.nrao.edu/astro/VOBS/astronomy/doc/readme-sniffer.txt
>>>     for instructions on how to interpret this
>>>     plot.
>>>
>>> 5. Delay, rate, phase, and amplitude plots were made for the
>>> observation.
>>>
>>> 6. Autocorrelation bandpass plots were generated for all antennas for
>>> scans
>>>     on all sources.
>>>
>>> 7. Cross-correlation bandpass plots were generated for all baselines
>>> to LA
>>>     for scans on all sources.
>>>
>>> 8. Gzipped PostScript plots of Tsys and other monitor data for each
>>> available
>>>     VLBA antenna can be found at:
>>>     http://www.vlba.nrao.edu/astro/VOBS/astronomy/jan13/bb310b.
>>>
>>> 9. The jobs associated with the correlation of BB310B can be found at:
>>>     http://www.vlba.nrao.edu/astro/VOBS/astronomy/jan13/bb310b/jobs.
>>>     These files provided the correlator with all ancillary data
>>>     needed for VLBI, including:  correlation parameters and telescopes
>>>     correlated in the final production.
>>>
>>>
>>>     Automated Calibration Transfer for VLBA Correlator Output
>>>     ---------------------------------------------------------
>>> The first phase of automated calibration transfer for data from
>>> the VLBA correlator has been completed, and was used
>>> for your observation.  This transfer of calibration information includes
>>> data from the 10 VLBA antennas, as well as selected information from
>>> the VLA, GB
>>> and Effelsberg, which currently provide VLBA-style
>>> monitor data.  Significant changes to AIPS have been required to
>>> introduce calibration transfer, so users must have the patched
>>> version of 15OCT98 AIPS, or any later version, beginning with 15APR99.
>>> It is highly recommended that users download the 31DEC10 version
>>> of AIPS to take advantage of new tools and current updates.
>>> Help files for a number of AIPS tasks have been updated to
>>> reflect the new calibration procedures.  There also is a new
>>> version of the VLBI chapter of the AIPS cookbook, available
>>> from http://www.cv.nrao.edu/aips/aipsdoc.html, that includes
>>> more details on how to cope with the calibration transfer process.
>>>
>>> The calibration-transfer process relieves observers of the
>>> burden of creating and inputting calibration files for VLBA
>>> antennas.  Instead, this information is now provided as tables
>>> attached to the FITS data sets output by the VLBA correlator.
>>> The ancillary data include antenna gain (GC table), system
>>> temperature (TY table), pulse calibration (PC table), flags (FG
>>> table), and weather (WX table).  The wise observer will not
>>> modify these original tables; processing errors might then force
>>> the data to be reloaded using FITLD.  See the description of
>>> MERGECAL in Section 9.2.1.7 of the new cookbook chapter for more
>>> detail.  Of course, skeptical users can simply delete the appropriate
>>> tables created by FITLD and generate their tables in the old manner.
>>>
>>> At present, ancillary data from most external telescopes must still
>>> be loaded in the old manner, and observations of strong sources
>>> may be needed for manual pulse calibration at those telescopes.
>>> Up-to-date instructions on coping with observations including
>>> external telescopes can be found at
>>> http://www.vlba.nrao.edu/astro/obscor/cal-transfer/.
>>>
>>> Please send comments on calibration transfer to amiodusz at nrao.edu,
>>> and send bug reports to daip at nrao.edu, with a copy to amiodusz at nrao.edu.
>>>
>>>
>>>     End of Letter
>>>
>>
>>
>>
>> ------------------------------------------------------------------------
>>
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>

-- 
   \_________________________________________________________________

  Andreas Brunthaler
  Max-Planck-Institut fuer Radioastronomie

  Auf dem Huegel 69            Tel.   :  +49 228 525 377
  53121 Bonn                   Fax    :  +49 228 525 229
  Germany                      e-mail :  brunthal at mpifr-bonn.mpg.de
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