Re: 'Official' TiPS elsets are very accurate (followup)

3432P@VM1.CC.NPS.NAVY.MIL
Sun, 17 Aug 97 23:45:29 PDT

Note: My first attempt to post this apparently disappeared into the
ether.  Apologies in advance if it shows up at a later date...

I observed TiPS August 18 at 05:43:44 UT in order to continue my
comparison of Naval Research Lab elsets published at
http://hyperspace.nrl.navy.mil/TiPS/latest_tips.els, with the
elset dated 97180 published in the Molczan file dated Aug 15th I
obtained from Mike McCant's FTP site. This was the most recent
non-NRL TiPS elset I had available.

The two NRL elsets I used were dated 97223 (7 days old) and 97228 (2 days),
and produced predictions virtually identical with each other in time (less
than a second apart), and the exact same track.

I feel somewhat guilty comparing the 50 day old 97180 elset to the more
recent ones from NRL, but I feel the results are worth mentioning.  Using
Skymap 5.10 (SGP4), the elset from the Molczan file was 22 seconds too
early, and .5 degrees above the actual track.  The NRL elsets were accurate
to within a second, and on track.  I used a 4.5 inch newtonian at 40x,
with a 1 degree FOV.

Although the 97180 elset is remarkably accurate considering its age,
observers wishing to see the tether in a telescope at high power with a
narrow field of view should consider using fresh NRL elsets; they've
produced great results for me.  I guess that's all I have to say on
that subject.  Aren't you glad?  :-)

Note: My timings are not done with a stopwatch (I don't own one), but
with a wristwatch set as accurately as I could to USNO time.  Errors
therefore could be +-1 sec.  I've always been impressed with observers
who report subsecond splits.  Maybe someday I'll have the right
equipment to be able to do that.  Does anybody have recommendations for
stopwatches and shortwave radios?  The radio is needed for picking
up the time signal, right?  I'm willing to summarize the results, so
feel free to send replies privately.  I think I generate too much
net clutter sometimes.

Craig Cholar   3432P@VM1.CC.NPS.NAVY.MIL