FW: Data to be collected in the 'master?' database

["Creager, Robert S" <CreagRS@LOUISVILLE.STORTEK.COM>]

-----Original Message-----
From: aah@nofs.navy.mil [mailto:aah@nofs.navy.mil] 
Sent: Friday, August 03, 2001 7:25 PM
To: Creager, Robert S
Subject: RE: Data to be collected in the 'master?' database


One more addition to the master database.  Sooner or later,
each frame will have a photometric calibration.  Since you
have reserved space for the astrometric calibration, you
might consider some paramaters for photometry.  The obvious
one is a zero point per filter, but if you have a star with
both V&I information, you can do the complete transformation.
That requires two coefficients per filter (a zero point and
a color slope).
  While ~7 apertures per star is a desired goal, I don't see
why it has to be a requirement.  Just allocate space and
use what photometry is available.

>Under the heading "For each night:", I have Extraction and Astrometric
>versions (I should add the Name I believe).  Is this what you're referring
>to?
  Not necessarily.  There are at least 4 parts to the puzzle:
      (a) calibration of the frame with dark subtract and flatfielding,
           possibly shutter corrections, bad pixel fixing, etc.
      (b) extraction of the basic starlist (this usually includes
            instrumental photometry)
      (c) astrometric calibration
      (b) photometric calibration
These pieces might be wrapped into a single pipeline program, or
might be separate programs that feed into each other.  So I'd place
a version number on each part, which might end up being the same version
number in some cases.  The more general you make the database, the more
methods can be supported.

>Darktime - I'm a little unsure on what you mean here, but I think this
would
>be have to be info calculated during the run, and so contained in the fits
>header, yes?
  Yes, just like exposure time.  It has to be a real-time calculated
parameter.
  
Arne