Re: Help observing Mir before Sun

From: Bj|rn Gimle <Bjorn_Gimle_at_lector.kth.se>
Date: Wed, 15 Mar 1995 11:25:33 -0500
Walter Nissen wrote in seesat/216 :

> Monday, March 13, 1995 13:23:28 Walter
Nissen,dk058@cleveland.Freenet.Edu,Internet
> Subject: Help observing Mir before Sun
>
> I am requesting assistance in identifying opportunities to observe Mir
(and
> the shuttle orbiters) pass in front of the Sun and Moon.  I'm not sure
this
> can be done.  If it can be done, I'm not sure what software I'd need to
> support a search.  I have a small machine.  Think of it as an 8088 laptop
> (actually it's a V20/8087 with almost 5 MB of internal storage).  Below
are a
> couple of excerpts from a (now obviously) primitive attempt for what
looks
> like a near miss.
>
> I guess my big question is:  What is ICE telling me?  Should I be using
> Apparent or Astrometric Positions for the Sun?  Are they for equinox
J2000.0
> (which is what I understand the TrakSat output is)?
>
> I'm not worried about TrakSat fouling up the sign for declinations
between -1
> and 0.  I see what is happening there and can eyeball it.
>
> Your comments about software and procedures would be appreciated.
> >
>                            Astrometric Places of SUN
>             Date              Time         RA             Dec
Dist
>   Julian Date   Year Mon Da  h  m  s    h  m   s        x  '   "       AU
>  2449790.45625  1995 Mar 13 22 57 00   23 34 10.276  -  2 47 29.53
.9940298
>  2449790.45694  1995 Mar 13 22 58 00   23 34 10.428  -  2 47 28.54
.9940300
>                            Apparent Places of SUN
>             Date              Time         RA             Dec
Dist
>   Julian Date   Year Mon Da  h  m  s    h  m   s        x  '   "       AU
>  2449790.45625  1995 Mar 13 22 57 00   23 33 54.883  -  2 49 08.07
.9940298
>  2449790.45694  1995 Mar 13 22 58 00   23 33 55.036  -  2 49 07.09
.9940300
>
>                               TRAKSAT  Version 2.80
>                     Tracking Station:  NISSEN, OH
        [ Line Of Sight (LOS) Visibility ]
>                               Satellite: Mir Complex
>
>                               Satellite Data Set:
>      1 16609U 86017  A 95 67.86666546  .00006921  00000-0  90668-4 0
9629
>      2 16609  51.6474 300.4481 0004353 212.3501 147.7219
15.57908368517321
>
>      Date    Time (UTC)   Azim     Elev   Range    Ra        Dec
Alt  V
>              HR:MN:Sec    Deg      Deg    Km       HH:MM:SS  DD:MM:SS
Km
>                                -- Rev # 51811 --
>  Mon 13Mar95 22:57:50.0   263.66   7.24   1619.72  23:33:28 +00:05:16
397  Y
>  Mon 13Mar95 22:57:51.0   263.44   7.29   1616.00  23:34:13 +00:02:36
397  Y
>
I think you should use SkyMap (by Rob Matson) alone, since it has Sun
and Moon transit search built in.
Though I agree that it should be run on a faster system, I may have been
one of the most persistent users of SkyMap on a 286,
and adding a co-processor to that system made it 2-5 times faster than
a 486SX25 when running SkyMap !

I believe SkyMap is still capable of running on your CPU
( Rob, can you give your opinion? ) - if not you might try an
older version, since the feature has been around for some time.

I ran a search for Sun using the 950305 Ted Molczan elsets (805 objects),
from 10:00 to 24:00 UT (limiting perigee to 2222 km and range to 9999 km)
on March 13. This took 66 seconds on my 486DX2/50, and although this may
take 10 hours or more on a 80286, and still hours on a 8087, it would
only be a matter of minutes with Mir and Shuttle only !

It should have about 480 kb RAM available, and needs 0.5 - 2 MB disk space,
depending on how faint stars you want plotted too ( plotting Sun,
stars and tracks approximately doubles the run time )

To get the output below, I did not use the published coordinates for
Cleveland, OH - I went NE to 43.5 N, 78 W, to make Mir have a transit
on that day !
            Start of Track     Transit Center       End of Track
  Date     Time   Azim Elev   Time   Azim Elev   Time   Azim Elev  NORAD
 3/13/95 11:35:27 100o  0o  11:36:11  95o  1o  11:39:32  68o  0o   05707
 3/13/95 23:09:46 266o  0o  23:09:48 266o  0o  23:12:15 276o  6o   11699
 3/13/95 22:16:44 238o  0o  22:19:59 257o  9o  22:31:02 354o  0o   12804
 3/13/95 12:55:37 141o  0o  13:00:41 110o 16o  13:10:46  22o  0o   13034
 3/13/95 12:41:36 143o  0o  12:45:48 107o 13o  12:52:47  30o  0o   13154
 3/13/95 23:02:40 309o  0o  23:07:21 266o  1o  23:07:53 261o  0o   14372
 3/13/95 13:07:13 145o  0o  13:12:31 112o 18o  13:22:24  21o  0o   14680
 3/13/95 22:56:27 274o  0o  22:57:30 264o  2o  23:03:11 193o  0o   16609
 3/13/95 17:25:07 185o  0o  17:31:32 183o 44o  17:42:27   9o  0o   17526
 3/13/95 18:03:50 189o  0o  18:10:12 196o 42o  18:21:09   8o  0o   18161
 3/13/95 14:38:41 168o  0o  14:43:53 132o 32o  14:51:50  16o  0o   18215
 3/13/95 12:07:09   3o  0o  12:20:42 102o  8o  12:23:56 118o  0o   19336

I can send the corresponding HP-GL .plt file, or a .PCX file, to
you personally, or to Bart for putting it into seesat-l-request,
if there is any interest for it, or if you will have problems
with SkyMap,

I can also run it for you with coordinates / elsets you indicate !

======================================================
Bjorn_gimle@lector.kth.se == bjorn.gimle@duesenberg.se
Received on Wed Mar 15 1995 - 03:59:48 UTC

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