RE: Automatic Processing of Data

[<aah@nofs.navy.mil>]

Rob asked:
>Any thoughts on minimum number of frames for a good dark/flats?  Or trying
>to quantatize how you reject images for flat creation?
  I'll think about it...
  Flat creation to me is an art with these sky frames.  If we were just
using 'dome flats', I could easily come up with an algorithm for
acceptance.  However, sky flats are quite subjective.  You might have
a plane or meteor.  A local light comes on or off.  The moon rises or
sets.  Twilight starts or ends.  The telescope field of view passes
through M31 or the Milky Way, or Sirius.  As long as you are trying
to make flats from sky exposures, you have to manually inspect each
and every one.  The flat is the most critical image for the entire night.
Any systematic problem effects every processed image.
Arne