[evlatests] Strange goings-on for AW703

[Mark Claussen]

Ken,

Thanks for reminding me about what was wrong that day.

Mark


On Wednesday 01 August 2007 09:22, Ken Sowinski wrote:
> This was the afternoon that miranda broke and networking at the
> VLA was, at best, slow for a long time.  The oeprator interpreted
> this as a vis-pipe failure and tried to treat it at as such
> without much success.  Not much useful was happening much of the
> time; logs may give some clue as to when the problem began and
> stopped.  If not James may have a memory of when things happened.
> 
> This program probably needs to be reobserved and someone should
> take advantage of the opportunity to fix all the observe file
> problems Mark noted.  In addition to what he reports I saw many
> examples of warnings in the executor log that the antennas were
> pointing within a fraction of a degree of the sun.  The quality
> of the data suggests that not much damage will accrue to having
> marked as 'public'.
> 
> Ken
> 
> 
> On Wed, 1 Aug 2007, Mark Claussen wrote:
> 
> > I took a look  at AW703, observed on July 29, 2007 as part of
> > checking on modcomp-free science observations, and found, that,
> > unlike most of the data sets I have looked at, this project had
> > some pretty strange goings-on.  I post this to evlatests in order
> > that others might comment or try to figure out what happened.
> >
> > This project was standard X-band continuum.  The start IAT was 19:12.
> > There were a couple of user errors that made this project iffy to
> > begin with: 1) the source names had embedded blanks, and most targets
> > were 3C or 4C sources so the names were like "4C 51.2".  Thus AIPS
> > interpreted all these sources as the same object with different
> > qualifiers.  Will be pretty tricky to sort out; 2) the project
> > code was ADA000 rather than AW703, so the data showed up in the
> > archive under ADA000, and marked *public*.
> >
> > The only log info about this project rather than the usual messages
> > were that 1) Antenna 18 was stowed because of a foc/rot problem and
> > that 2) for about 1/2 hour (2035 - 2104) VISPIPE gave no data.
> >
> > The curiosities with this data were:
> >
> > 1) For most scans, there is some period of time at the beginning
> > (can last up to minutes) where there are no fringes for any combination,
> > then at some point the fringes pop up and are there for the rest of the
> > scan, as if the antennas are off source or something.  But the data is
> > not flagged by the online system.   A specific example of this is:
> >
> >     There is a 10 minute scan on 1411+215 in the middle of the
> >     run (215620 - 220600, scan listing).  For all antennas, there
> >     are no fringes on this source until 220430.  Nothing in the
> >     log, and the data is not flagged.  After 220430, fringes on all
> >     baselines look good.
> >
> > 2) There is data coming from Antenna 18.  No fringes, as would be 
> expected
> > since the antenna was apparently stowed, but the data wasn't flagged.
> >
> > 3) Antenna 11 had data on EVLA baselines.  There were no fringes, and data
> > 11-VLA baselines must have been flagged.
> >
> > 4) For at least one scan and possibly others, there were data only for
> > EVLA-EVLA baselines.
> >
> >
> >
> > It seems like something was fairly messed up for this run, as opposed to
> > other data sets that I have looked at recently, where the data looks very
> > good.
> >
> > Mark
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> 
>