[daip] [Fwd: Re: BB310B data]

Thu Mar 21 10:11:06 EDT 2013

It's only an aips thing.  Nothing to do with correlation.

Amy

Andreas Brunthaler wrote:
> 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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>>
> 
> 