[daip] Re: Reference Antenna: How to choose?

[Eric Greisen]

Gregory Tsarevsky writes:

 > Would you please advise me how to choose refant before the VLA data
 > processing?
 > 

      Often the tasks themselves can choose one sensibly.  Otherwise,
the best choice is an antenna that occurs all the time and does not
appear noisier than the others.  If you load data with DOWEIGHT > 0,
then the weights will represent 1/Noise**2 although they are not yet
calibrated.  An antenna that has higher weights is then likely to be a
better choice - although it would be best to examine (with DOCAL=2)
the weights after the first attempt at cal to pick the highest weight
antenna.  With the VLA, which is very overdetermined and generally
reliable, the choice is not that important.  An inner antenna rather
than one of the outermost is also a good idea.

Eric Greisen