Re: Decay over aircraft in the Pacific.
Alan Pickup (alan@wingar.demon.co.uk)
Tue, 27 Aug 1996 19:01:15 +0100
In message <3222C212.1637@tt-tech.se>, "Bjoern Gimle@tt-tech.se"
<bjorn@tt-tech.se> writes
> ...<Mega-snip>...
>Tonight, I will post MM charts and SkyMap stereographic space views
>of the tracks of #23797 and #24281 on my www pages, but I think we
>could use more accurate time (and date!) of the aircraft observation,
>and the position relative to the aircraft, and the results of a
>(SatEvo?) integration matching the last four or so elsets,
>to settle this.
> ...
Ok - you asked for it..
Radgua 33 SL-12 r2
------------------
In my final analysis, I did not try to bridge the a long interval
between OIG elsets dated 96232.141 and 96234.188. Instead, I simply
took the 96234.188 elset and tweaked the ndot term to give the same
equator crossing time as the 96234.256 elset, the only later elset we
have for this object. The resulting evolution...
Raduga 33 SL-12 r2 1298 x 90
1 23797U 96010D 96234.18818470 1.16003375 46580+0 14170-2 0 93227
2 23797 47.7434 197.2551 0853515 79.7695 289.7368 14.59757501 5539
Raduga 33 SL-12 r2 1192 x 90
1 23797U 96010D 96234.25611252 1.26617896 58703+0 14718-2 0 93222
2 23797 47.7391 196.9295 0784923 80.0748 288.6862 14.76207011 5545
Raduga 33 SL-12 r2 1080 x 90
1 23797U 96010D 96234.32324321 1.40608723 81299+0 15425-2 0 93225
2 23797 47.7328 196.5996 0710612 80.3842 287.5657 14.94096724 5559
Raduga 33 SL-12 r2 958 x 90
1 23797U 96010D 96234.38951682 1.59776745 11852+1 16326-2 0 93227
2 23797 47.7257 196.2650 0628592 80.6982 286.3520 15.13930928 5569
Raduga 33 SL-12 r2 822 x 90
1 23797U 96010D 96234.45484794 1.88948180 18891+1 17646-2 0 93222
2 23797 47.7198 195.9248 0535446 81.0175 285.0022 15.36552636 5571
Raduga 33 SL-12 r2 662 x 90
1 23797U 96010D 96234.51909498 2.47868049 50329+1 20268-2 0 93229
2 23797 47.7101 195.5782 0422976 81.3429 283.4228 15.64036073 5586
Raduga 33 SL-12 r2 437 x 90
1 23797U 96010D 96234.58192192 4.32893606 22833+2 27180-2 0 93224
2 23797 47.7000 195.2231 0260951 81.6765 281.2737 16.03891233 5592
If decay occurred at or near the following perigee, it would have been
at about 96234.60 (= August 21.60) as per my SatEvo decay list #12 which
I posted here on August 24. However, I'm not totally happy with the way
SatEvo grappled with this object - SatEvo tended to predict too early a
decay over the final few days. However, I'm certain that it
couldn't/shouldn't have lasted until the 22nd.
Soyuz r
-------
Here I iterated the n and ndot terms in an elset dated 96233.554 to fit
(to with 0.02s) the equator crossings indicated by elsets dated
96234.164 and 96234.407. The resulting evolution satisfies an equator
crossing at 96234.225 to within 0.6s and predicts an equator crossing
only 2.1s earlier than that indicated by the final OIG elset dated
96234.529. The evolution over the final revs runs ...
Soyuz r 165 x 156
1 24281U 96047B 96234.22536477 .08510125 72189-1 47361-3 0 90245
2 24281 51.6141 155.1457 0006771 112.9967 247.0757 16.41997032 601
Soyuz r 162 x 154
1 24281U 96047B 96234.28620108 .10069261 10574+0 44533-3 0 90245
2 24281 51.6138 154.8004 0006087 113.2547 246.8112 16.43121328 611
Soyuz r 157 x 151
1 24281U 96047B 96234.34699157 .12474019 17184+0 41051-3 0 90241
2 24281 51.6134 154.4547 0005316 113.5129 246.5429 16.44479880 627
Soyuz r 152 x 146
1 24281U 96047B 96234.40772512 .16751870 33517+0 38590-3 0 90244
2 24281 51.6129 154.1087 0004414 113.7715 246.2748 16.46225739 634
Soyuz r 145 x 141
1 24281U 96047B 96234.46838128 .26964395 98395+0 38508-3 0 90249
2 24281 51.6123 153.7620 0003273 114.0306 246.0037 16.48765473 644
Soyuz r 128 x 127
1 24281U 96047B 96234.52890278 1.13528264 23168+2 63090-3 0 90240
2 24281 51.6111 153.4143 0001381 114.2904 245.7240 16.54567712 658
Again, if decay occurred near the next perigee, it would have been at
96234.55 (=August 21.55). Or, as Mike suggests, it might already have
decayed on the previous rev.
Does this help?
Alan
--
Alan Pickup | COSPAR site 2707: 55d53m48.7s N 3d11m51.2s W 156m asl
Edinburgh | Home: alan@wingar.demon.co.uk +44 (0)131 477 9144
Scotland | Royal Observatory: A.Pickup@roe.ac.uk +44 (0)131 668 8224