[daip] Re: ATMCA with VLA data

[Leonia Kogan]

Ed,

How have you determined that
"ATMCA seems to read zero phases from the SN table for all VLA antennas, 
even though the SN table has reasonable phases"?

If you look into the output/intermediate SN table then it has phase at 
REAL and zero
at IMAG as the result of twopi ambiguaty solve. You may interpretate 
this as phase =
atan2(image, real) =0!!!  Therefore suach a phase estimation will give 
zero, what is correct.

If you find zero phase differentely or you still have a problem then,

1. Run TASAV, create fits file of the output and send it to me.
2. send me input parameters you use for ATMCA

Leonia

Ed Fomalont wrote:

> Hi Leonia,
>
>    I am trying to use ATMCA with VLA data.  I observed in the same way 
> as with
> VLBA data and want to fit and phase gradient using four sources.  
> Howvere, ATMCA
> seems to read zero phases from the SN table for all VLA antennas, even 
> though the
> SN table has reasonable phases.
>
>   First, question:  Is there any reason why an SN table from the VLA 
> should not work in
> ATMCA.  The only thing I can think of is that the limit to the number 
> of telescopes might
> be a problem.
>
>   If there is nothing obvious, I will be happy to send you the data 
> with some more
> comments.
>
>   I hope your health is going well.
>
>   Thanks, Ed
>
> PS.  I am in Holland, so you won't be able to telephone my in 
> Charlottesville.