"bad" elset for #16194 (Met 3-1 r)
Mike McCants (mikem@fc.net)
Thu, 26 Dec 1996 18:01:38 -0600
Ron Dantowitz said:
>While tracking Met 3-1 r (#16194 / 85100 B) the satellite was "missing",
>coordinates, but the satellite was TWELVE+ seconds late! (12.2 secs late).
The problem is a "bad" elset.
This rocket has had a very slowing declining mean motion for
a number of weeks (Longitude resonance?). However, the mean motion
for the elset issued by Spacecom on 354.46 is inconsistent with elsets
before and after it.
1 16194U 85100B 96353.92809876 .00000045 00000-0 10000-3 0 2974
2 16194 82.5628 152.4343 0016180 324.8170 35.1828 13.06536424531625
1 16194U 85100B 96354.46417659 -.00000590 00000-0 10000-3 0 2985
2 16194 82.5659 152.0718 0015464 320.5954 39.4547 13.06525582531693
^^^^^^^^^^^
1 16194U 85100B 96354.92362136 +.00000045 +00000-0 +10000-3 0 03058
2 16194 082.5604 151.7414 0016128 323.5312 036.4645 13.06535801531759
1 16194U 85100B 96355.53625161 .00000045 00000-0 10000-3 0 2998
2 16194 82.5652 151.3283 0015008 319.5170 40.4552 13.06532111531837
1 16194U 85100B 96356.91467507 .00000045 00000-0 10000-3 0 3002
2 16194 82.5651 150.3732 0015371 315.8274 44.1577 13.06531072532015
By coincidence, this elset was the one sent out in Ted's weekly
file last Thursday. So, by the time you observed the object, the
combination of a mean motion that was 0.000100 too small and a
negative drag term of -.00000590 if you use a program that uses
that value caused the discrepancy. 0.00010 times 9 days is
0.0009 revs * 6600 seconds per rev = 6 seconds. The negative
drag term would also contribute 4 or 5 seconds.
Mike McCants
mikem@fc.net