[daip] DOBAND=1 looses channels 1, N

[Eric Greisen]

Michael Bietenholz writes:
 > > Is this VLBI data?  The bandpasses have to be shifted as a function of
 > > time and antenna due to the way VLBI correlators work.  This usually
 > > causes one or both of the outer channels to be flagged.
 > 
 > It is VLBI data, so that would probably explain it.  Does this mean
 > that those channels are bad even if no BP correction is applied?  I
 > would naively expect that if the data is good, one could in principle
 > find a BP correction to apply at that would cover the whole range of
 > the available data.

I suspect that the answer is that the calibrator sources were not
observed at the frequency of the unknown and so there was no
measurement of exactly what one wanted.  No one has worried much about
these things because channels 1 and N are usually not very reliable
anyway.  I was about to look at this a little because I do not
understand something I ran across in the code - but the full business
is too much for my poor, non-VLBIer brain to understand.

ERic