Re: USA 86, 116, 129 elsets

Björn Gimle (b_gimle@algonet.se)
Wed, 23 Dec 1998 08:01:54 +0100

Tony Beresford timing of (possibly) USA 86 can matched by changing
ndot2 and B* upwards by about 50%. However, the resulting track
is four degrees below his observed point, instead of two degrees above.
This might be reduced by assuming other minor errors in the elset.

USA 86      
1 22251U 92 83  A 98355.47065982  .00005600  00000-0  37329-3 0    17
2 22251  97.7342  52.7168 0414482 251.1886 104.3936 14.57085645  9773

Near Nov.1 USA 116 and 128 were separated in time corresponding to
57.4 degrees, 5.9 degrees more than their orbital planes, and were
also having Mean Motion around 14.805.
Both these values are close to their operational limits, so I assume
they were boosted at that time to MM=14.71 or so.

USA 116     
1 23728U 95 66  A 98304.91150611  .00025000  00000-0  32931-3 0    18
2 23728  97.9280  55.9067 0510376 330.8139  26.5404 14.70371923  7689
USA 129     
1 24680U 96072  A 98304.88668923  .00024000  00000-0  31965-3 0    15
2 24680  97.9670   4.3501 0507259 119.3955 245.8886 14.70556669  2095

However, an uncertainty of +/- 5 days would completely ruin the
predictive value of this elset (except it gives a probable orbit shape)
A ten percent error in the drag terms would also have accumulated to
more than two orbits by now !

Create multiple elsets, adding 30, 60, ... to the mean longitudes
(26.5404  and 245.8886 ) to use for searching.