which catalog to use as "astrometric seed"?

[Stupendous Man <richmond@p674p06.isc.rit.edu>]

  Chris asks a tough question:  which catalog should we use
to "seed" the TASS database so that (most) stars are _already_
in it, at their proper positions, before we start to stuff 
TASS detections into it.

  Option 1: the Guide Star Catalog

            pro: easily available
                 covers entire area
                 ready NOW
                 we already have a copy here at the TASS WWW site 

            con: not complete -- it won't contain some TASS detections
                 may contain _small_ systematic errors (but these should
                     almost all be smaller than the accuracy of the 
                     TASS positions, so that's not very important)

  Option 2: the USNO-A catalog

            pro: goes much, much deeper than TASS, so contains all our stars
                 positions are better than GSC
                 ready NOW
                
            con: I don't have a CD-Rom with the catalog
                 covers whole sky, is really big -- may be unwieldy at first

  Option 3: subset of USNO-A (and ASC) to V=16 Arne is making
           
            pro: goes deeper than GSC -- may still be a few red stars which
                    we detect but it does not
                 has very good positions
                 much smaller than the full USNO-A catalog, easier to handle
 
            con: Arne hasn't made it yet
                 Arne may be busy for the next few weeks 

  I guess I'd like to see us adopt Option 3, but if it can't be done in 
time for Chris, I'd say go with Option 1.  Chris and I can both grab
a catalog of GSC stars in the celestial equator from the TASS WWW site

         http://p674p06.isc.rit.edu/tass/software/software.html#mgsc

On the other hand, these data come from an old version of the GSC,
so there are some known errors in it ...

  Perhaps Arne can tell us how hard it would be select just those
stars we want from the USNO-A.  We can all try using the WWW tools
below to make our own subsets, without the CD-Rom, but I suspect that
it will take quite a while :-(

        http://asteroid.lowell.edu/cgi-bin/koehn/webnet  
        http://archive.eso.org/skycat/servers/usnoa_res  (better)

                                        Michael