Hi David,
I saw your post on MPML as well... I'd only add that it _is_
necessary to update the satellite database from time to time.
The elements are good for maybe a few weeks, maybe a few
months (varies a lot, depending on the object altitude).
Use of 'alldat.tle' will get you almost all satellites. Every
now and then, somebody asks me about a satellite they've
imaged that doesn't match any object in 'alldat'; in each case,
it's turned out to be something that hasn't been observed in
a while and for which no good orbit existed.
Given your location, you may prefer to grab the mirrored
copy of 'alldat.tle' from Tony Beresford's site:
http://home.iprimus.com.au/aberesford/
Also, while you can use Guide to identify satellites found in
your astrometry program, you may find this little utility to
be slightly more convenient. Or maybe not... but the comments
on it will still be useful:
http://www.projectpluto.com/sat_id.htm
-- Bill