[daip] vsad in aips

[Eric Greisen]

VSAD is not in the aips distribution.  I will bet that VSAD will
compile and run correctly with any non-binary version of AIPS.
Certain imaging routines in Bill's package have a problem with 31DEC03
and later but I would not think that this would affect VSAD.  Note
that VSAD requires the fit Gaussian to be no smaller than the beam.
This is non-physical since noise can easily make a point source be
either smaller or larger than the beam.  VSAD introduces a bias in
allowing the one while prevenmting (at great cost) the latter.  VSAD
may be better at handling difficult regions than AIPS' SAD but I am
not familiar with that aspect.

Eric Greisen