Table info

[Doug Welch <welch@physics.mcmaster.ca>]

I have a few comments/questions/suggestions about the info below.
Is there a flag for drift-scan or not? (If it is a drift scan, then
the mid-JD will depend on one coordinate.) Additional useful info
would be a short integer for number of missing/bad pixels within the
aperture. It has certainly been my experience that uncatalogued
charge traps are a major source of variation of non-variable stars
and that the number of missing/bad pixels in a stellar footprint
is a good way to identify them. I would also recommend a short integer 
to represent "crowding"  - are there stars nearby that could cause 
seeing-correlated probems?

Finally, observer longitude and latitude should be sufficiently
fixed that they could appear in the header.

Cheers,
Doug
 
> 
> Header
> -----------
> JD Julian Day
> FILTER
> EXPOSURE exposure time
> DATE-OBS start of observing (date + time)
> OBSERVER observatory code or information how to get observatory coordinates
> RA-CENTER
> DEC-CENTER
> CRVAL1, CRVAL2, etc..
> PLATE constants
> APERTURE_SIZE (diameter in pixels)
> PSFFUNCTION ? (I guess this would be needed)
> 
> Table
> ------------
> XT, YT image coordinates
> SXT, SXT error estimates for the above
> PSFMAG, PSFMAGERR magnitude and error estimate obtained by PSF
> APERTUREMAG, APERTUREMAGERR magnitude by aperture method
> FWHMX, FWHMY star shape useful for quality control
> ROUNDNESS, SHARPNESS (additional shape parameters)
> PEAK_DN (to decide whether a star is saturated, etc.)
> SKY_DN