Re: Working on Data

[Stupendous Man <richmond@a188-l009.rit.edu>]

> Michael, if you work out a fix for this, will it require rerunning all the 
> data?

  Nope.  The fix can be done with the information in the .cal files
from each night, as long as the associated .list files are present
as well.  There's no need to go back to the images.

  Removing the obvious spatial error in V-band reduces the scatter
in (Tycho Vt - TASS V) by something like 15 to 30 percent.
I'd call it worthwhile.  

  Arne wrote:

> I was able to use the 1.3m two nights ago and got 4x2degree
> swaths of the 16hr SDSS calibration field, plus about 2x2degrees
> in another calibration field ("O") at 21hrs. 

  Hmmm.  The data I've been using to test this correction comes
from 5 CD-Roms Tom mailed me.  It _does_ include the region 
around RA = 16 hours, but there's nothing in it around RA = 21 hours.
Still, the 16-hour field will help a lot as I try to go from 
our intermediate Tycho2 system to the Johnson-Cousins system.

                                   Michael