[Difx-users] pcal_200213 bug in difx2fits

[Leonid Petrov]

Jan,

> It reflects the VEX 1.5 $IF block element "P-cal base freq". It
> allows to describe up-mixed PCal comb generator output. For example
> Wettzell twin telescope was experimenting with shifting PCal of one
> antenna by 500 kHz relative to the other antenna, to prevent tones
> from dominating the visibility data on the very short baseline. Ny
> >Alesund could be a similar case.
 > 
> Wettzell in the end chose to enable/disable PCal on alternate scans
> (shifting was tricky), and made do without PCal for half the time.

  Although I do not think it is a good idea to shift base pcal 
frequency -- there is a much more simple solution of handling short
baselines, if somebody does it, difx2fits should support it.

  Then it has sense to round the pcal frequency to a Hz, not MHz.

Leonid
2020.02.14_11:34:50