Iridiums 970807, 970901, 970919

Bjoern Gimle (bjorn@tt-tech.se)
Mon, 22 Sep 1997 15:10:43 +0200 

I came home from a business trip during the first expected flare Friday,

left the taxi just in time to see the second one at 19:45 UT,
and missed the third at 19:54 because of accumulating clouds.
My friend, Bengt Ottosson, who saw one flare from Iridium 6 (?)
on 07.August, saw all three.

Old reports, Aug. 21 and 26, have been amended.

  NORAD   date       time   Dir  aI eI  aM  eM  aS   eS Phs  Dur  Mag
Obs
  xxxxx  dd-mm-yy  hh:mm:ss  x  xxx xx  xxx xx  xxx -xx xxx  tt  Sn.n
II

  24794  07-08-97  19:58:xx  S   xx xx   77 54  318  -6  xx   x  -2
BO
  24839  21-08-97  20:27:00  S   28 30   73 41  324 -13  74 <20  -1.0
BG
  24839  21-08-97  20:27:20  S   33 33   73 41  324 -13  81 <20  -1
BG
  24836  26-08-97  19:57:2x  S   42 36   73 40  317 -12  93   5   3
BG
  24841  26-08-97  20:06:4x  S   43 41   75 46  319 -13  96  >6  -1
BG
  24842   1-09-97  19:38:52  S   45 46   76 50  312 -12  99  >1   1?
BG
  24837   1-09-97  19:40:01  S   55 50   76 50  312 -13 106  >3   0?
BG
  24869  19-09-97  19:35:xx  S   4x 3x   70 33  310 -19 10x   8?  x
BO
  24871  19-09-97  19:44:4x  S   44 34   72 38  312 -20 103   8?  0
BG
  24872  19-09-97  19:54:xx  S   5x 4x   74 43  314 -21 10x   8?  x
BO

 BG = 59.2237 N , 18.2286 E, +44m
 BO = 59.322  N , 18.455  E, +15m

I have used SkyMap to find the Sun position and Phase.
Since I have the track displayed, and (nearly) correct time, I just
get the F4/F2 menu and type 'Sun', to get current aS/eS.
Back to the previous position (or restore saved .cfg) I get aI/eI
from the cursor, and with SkyMap 6.0 beta I have got a Track query
which gives 'the phase angle (measured from satellite to observer
to sun), ' (and other things).

Ron's mail Sep.19 does not describe where Phs is measured - this
must be clarified !
In QuickSat 'The Phs value is the sun-object-observer angle'.

In Ron's table, BD and LB appear to use the observer angle,
EL, JR, PM and SW the satellite angle.
BD's mail
(http://www2.plasma.mpe-garching.mpg.de/sat/seesat/hyper/0482.html)
also uses satellite angle ?

When we agree on a definition, replace non-conforming Phs by 180-Phs.


--

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