[evlatests] Phase jumps on EA14

[Jim Jackson]

I would second and add to Michael's comments from an Engineering & 
Operation point of view.  We currently have a three antenna rule in 
maintenance - ie, three antennas have to be down before an after hours 
call out. Budget & manpower shortages are likely to force us to increase 
that number. Having specific antennas that must be up for various 
purposes would negate that. The system needs to be flexible enough, 
either automatically or with operator intervention, to accommodate any 
antennas being down without affecting the operations of the entire array.

Jim

Michael Rupen wrote:
> In general it would be nice if the pipeline were smarter about choosing
> reference antennas.  ea14 should of course be fixed, but one bad antenna
> should not produce such a "ripple effect" downstream.
> 
> The intelligent choice of a ref.ant. is not entirely trivial.
> An interim solution might be to use the same antenna we use as a reference
> for TelCal, which we tend to keep a careful eye on operationally.
> This has the benefit of matching the reference used for phased array
> work.  That reference antenna at the moment is ea12, but might more
> usefully be described as the antenna on pad E8 -- one of the three
> antennas which is never moved when we change configurations, and central
> enough when it matters (i.e., for the more extended configurations).
> 
> There is no obvious place in the SDM proper at the moment to store the 
> suggested reference antenna.  We might consider adding an element to the 
> ExecBlock Table to handle this:
> 
>    Optional:
>    numRefAntenna  int
>    refAntenna[Nrefant], Tag[Nrefant]
>    description: "default reference antennas for calibration, in order
>      of preference"
> 
> We actually do send such suggestions to TelCal at the moment, so recording
> that information (esp. useful for phased-array data) would seem reasonable.
> 
>             Michael
> 
>> Hi All,
>>
>> We are seeing phase jumps on EA14 and right now the pipeline is choosing
>> EA14 as a reference antenna so, when there is a phase jump, the pipeline
>> output is not usable.
>>
>> Is there anyway someone can go out to EA14 on Maintenance day tomorrow to
>> see if this can be fixed?
>>
>> Thanks,
>> Deb
>>
>>
>>
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