[daip] Re: SNFLG question

[Mark Reid]

On Wed, 30 Jul 2003, Eric Greisen wrote:

> Mark Reid writes:
> 
>  >    I'm using SNFLG on VLBA data with 4 IFs and 2 Polarizations.
>  > Basically the phases in each IF and polarization are the same
>  > (after preliminary calibration to align the delays and phases
>  > of the bands using a strong calibrator) since they are dominated 
>  > by atmospheric effects.  However, it looks like I have to 
>  > run SNFLG 8 times, making pretty big FG tables.  
>  > 
>  >    Could some paramters be added that let one use say
>  > one IF and one polarization's phases and write out FG entries
>  > that apply to all IFs/Pols?
>  > 
> 
> Tomorrow's MNJ will bring a revised version that should be
> interesting.  Would it also be good to add delays and rates to this?

    I assume you are asking should one flag on delay or rate jumps.
I've never thought about that.   My first guess is that rates are 
unlikely to be useful, especially for short scans on phase reference
sources.  However, delays might possibly be useful, if they were
fitted for.  Clearly any delay change approaching an inverse 
bandwidth would indicate a problem.  However, I doubt that happens
unless the SNR for the fit was very low.  I guess I've talked my
self into saying don't worry about delays and rates.

Mark


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Mark J. Reid                 Phone: 617-495-7470 
Harvard-Smithsonian CfA      Fax  : 617-495-7345
60 Garden Street             Email: reid at cfa.harvard.edu
Cambridge, MA 02138, USA     Web  : cfa-www.harvard.edu/~reid                  
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