TJM obs of 2005 Aug 15 UTC incl Gorizont 14

From: Ted Molczan (seesat@rogers.com)
Date: Mon Aug 15 2005 - 08:23:14 EDT

  • Next message: Alberto Rango: "4541 Satobs 14 Aug 2005"

    I awoke to a clear sky and Peter Wakelin's report of 77044A somewhat off-track
    relative 2 month old elements, so I decided to have a look.
    
    I took advantage of Peter's observation to produce a preliminary orbit, which
    enabled me to obtain one accurate position. In the course of my analysis, I
    discovered that Alberto Rango's observation of 2005 June 17 UTC was about 1.3
    deg off in cross-track, probably a result of reducing the wrong star(s). The
    latest elset available to Peter had been fit to that observation, which most
    likely accounts for the large prediction error. I was unable to find the actual
    reference stars that Alberto used.
    
    This orbit should be pretty accurate; however, it was fit to a long period,
    during which drag was greater than it is now, so the object likely will run
    slightly late relative to it:
    
    DMSP B5D1-2      6.4  1.7  0.0  6.5 v 31.6
    1 10033U 77044A   05227.33733299  .00000103  00000-0  41204-4 0    06
    2 10033  99.1012 188.6521 0041128 253.7550 105.9103 14.27887149    05
    Arc 2005 Apr 27.14 - Aug 15.37, WRMS residuals = 0.014 deg
    
    While waiting for 77044A, I spotted a distant flasher, which turned out to be
    Gorizont 14 (87040A / 17969), an inactive communications satellite, about 700 km
    above the geosynch altitude.
    
    Gorizont 14 flashed to magnitude 6 with a period just under 45 s. Except for
    these brief flashes, it was invisible in 11x80 binoculars. I tracked it through
    94 flashes, of which I timed nearly 60 percent. I can produce the UTC time of
    each timed flash, if anyone desires the data. Please specify preferred format.
    
    17969 87 040A   2701 G 20050815084333580 17 25 0050850-095407 48 H+060 10 044870
    10033 77 044A   2701 G 20050815084624580 17 25 0046899-110957 18 R
    17969 87 040A   2701 G 20050815085401780 17 25 0100923-091655 97 H+060 10 044890
    17969 87 040A   2701 G 20050815090515230 17 25 0111041-084258 48 H+060 10 044880
    
    IOD format: http://www.satobs.org/position/IODformat.html
    
    87- 40 A 05-08-15 08:54:01.8 TJM 673.1 0.2  15 44.87  +6.0->inv
    87- 40 A 05-08-15 09:03:00.6 TJM 583.8 0.2  12 44.90  +6.0->inv
    87- 40 A 05-08-15 09:18:43.1 TJM 942.5 0.2  21 44.88  +6.0->inv
    87- 40 A 05-08-15 09:35:11.0 TJM 987.9 0.2  22 44.90  +6.0->inv
    87- 40 A 05-08-15 09:52:23.6 TJM 987.9 0.2  22 44.90  +6.0->inv
    
    PPAS format: http://www.satobs.org/tumble/flashpm.html#PPASformat
    
    Site 2701: 43.68764 N, 79.39243 W, 230 m
    
    Ted Molczan
    
    
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