Update to message below below....
TVCALC seems to work OK in Y2K, but as mentioned 
below, there are some glitches when the TLE elements are
from 1999.  The main problem is with the "current" sat position 
calculation, which includes drift since the epoch
time of the elements.  I have an error that makes the
program thing that 365 days have gone by, making it include
a whole year of drift.  So use the sat position at epoch
time, which will be OK.  All problems "SHOULD" dissappear
when year 2000 elements are used.  I have uploaded a new
TVRO.TLE file which I just downloaded from NASA.  It has
about half of the satellites with year 2000 data, but the
other half of the sats still have 1999 data. Check back in
another week, and all the sats should have 2000 data.
Please report any problems.


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TVCALC is not yet Y2K compatable, or more accurately 
it isn't compatable with any new year.  Ie it often has 
problems when the orbital elements in the tvro.tle file
are from the previous year.  In any event, I don't intend
to try to fix any problems with the program until after
they occur, so if, as is expected, there are problems with
the current version after new years, I should have a working
version posted within a few days. In the meantime, try 
getting the most current elements for all sats, and/or 
edit out any sats with 1999 elements, and the program 
"SHOULD" give useable results, even though I expect some
glitches.   Also, please report any glitches you notice.
Thank you.