Re: [TASS] photometric vs. non-photometric

["Arne A. Henden" <aah@NOFS.NAVY.MIL>]

As Michael says, it is very hard to tell from a single
image if it is photometric or not.  My plans were for
real-time analysis of (at least) the Landolt field frames
to keep a running calculation of the night quality, and
then in real time switch from one program to another.
The concept of using previous mean values for the
coefficients to determine whether the current night
is photometric is only valid for a crude estimate.
Extinction changes on a nightly basis.  I know what I
do here for photometric/non-photometric decisions, but
have not expounded in great detail until I see how
well the Mk4 can do photometry.  Note that this question
is only important for those sites that want to contribute
all-sky photometry rather than doing differential projects.
I expect the photometric sites to be few and far between.
A few nights (<40) per year at a typical midWestern site
qualify for my usual criteria.
  Back to IR processing...
Arne