USA 129 Was: Re: One more iteration

Bjoern Gimle (b_gimle@algonet.se)
Sat, 6 Sep 1997 17:24:58 +0200

I commented the usefulness of
>> 
>> 96-72A     Pierre Neirinck's elset #110     mean dev 1.7'
>> 
Rainer Kracht informed me that Pierre computed

>96-72A orbit #110 from 9 observations Aug 22-27
>

I realize that for some uses, like Ron Dantowitz' high-power
video shots, Pierre's accurate elsets are needed. But they 
may include effects of shortlived solar phenomena, as evidenced
by a 20 % change in drag between Pierre's elset #110 and #119
(from day 239.87 to 241.83 !)

USA 129 Pierre's #119 +obs.0718-0903 RMS dev.27'   1016*264 km
1 24680U 96072 A  97241.83890517  .00012910  75204-9  12948-3 0    20
2 24680  97.8381 301.7735 0535209  68.2363 297.4914 14.76610973    06

was computed from 58 observations over 47 days by Russell Eberst
and Peter Wakelin. ( I have written a program to convert a bunch
of mails from both into separate ELCOR files for each object )

ELCOR shows the maximum error to be 2.36 degrees (along+cross track)
FITELEM gives 0.88 degrees cross-track, and 12.3 seconds (!) 
along-track ( 3.8 seconds excluding the oldest pass )

This may be useful to amateurs who don't update their elsets
frequently, or just want to detect the large effects of a maneuvre.

NB: My epoch is slightly smaller than Pierre's, so automatic
TLE updaters may reject the elset !


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