[daip] [Fwd: Re: BB310B data]

Wed Mar 20 18:19:02 EDT 2013

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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