re: How visible are flares???

Walter Nissen (dk058@cleveland.Freenet.Edu)
Wed, 27 May 1998 08:34:01 -0400 (EDT)

> 1. Do you accurately know the latitude, longitude, and elevation data for 
> your site? 
> 2. Did you correctly enter this data into your prediction program? 
> 3. Did you make a mistake when specifying your time zone? I use UTC for the 
> date and time. 
> 3. Are your Iridium orbital elements less than one week old? 
 
a.  Did you enter your longitude with the correct sign?  East is supposed 
to be positive, but some older programs from the Western hemisphere may 
use the old convention.  If you are using more than one program, is it 
correct everywhere? 
 
b.  Did you confuse standard time and daylight time?  UTC is pretty 
convenient.  I run my PC on UTC. 
 
c.  These elsets are less than 1 week old: 
Iridium 48       3.0  0.0  0.0  6.0 d            780 x 775 km 
1 25107U 97082D   98146.24514426  .00015012  00000-0  53259-2 0  1231 
2 25107  86.3962 284.4531 0003838  66.7932 293.3651 14.34362860 22531 
Iridium 48 
1 25107U 97082D   98141.15255854 -.00003697 +00000-0 -12622-2 0 01588 
2 25107 086.4074 286.5779 0004213 070.0837 290.0753 14.36753424021801 
Yet this morning the culminations computed from them differ by almost 15 
minutes in time and 17 degrees in altitude.  Ouch!! 
And the frequently helpful TIM parameter in QuickSat required a 
hair-trigger sensitivity, as it barely blipped. 
The currently accurate, first, one is from Alan Pickup's file.  The 
second, I think, is from molczan.tle. 
 
Cheers. 
 
Walter Nissen                   dk058@cleveland.freenet.edu 
-81.8637, 41.3735, 256m elevation 
 
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Carpe noctem!