Frequencies of Iridium passes/flares

=?iso-8859-1?Q?Bj=F6rn_Gimle?= (
Mon, 24 Aug 1998 22:40:50 +0200

My reply to on =
Jul 28 (?)
never reached SeeSat-L - but that was before the temporary move ??
When will it end?

I have found some interesting repeat sequences of Iridium flares - I'll =
that when I have checked some more.

>14.34217268, and the mean MM is 14.34217189.  Choosing one of these as =
>average, the average period is 100.40320 minutes (6024.1920 s for us SI =

>fans) and the average interval between successive passes, or glints, I=20
>suppose, for the 11 operational satellites in each orbit is 9m 7.65381s =

No, MM is anomalistic (perigee-to-perigee), and the precession rate for
operational Iridiums is about 3.4 deg/day, or 0.237 deg/orbit, or .066 %

This gives P=3D100.469 minutes. Actually I think it is 100.465116, which =
a particular satellite reappear at the exact same time three days later
(43 orbits in 4320 minutes)

This of course is no repetition of pass characteristics, since the orbit =
precessed in RA, and the Sun has a different location. A search to find =
accurate repetition of a pass gave larger than a month. Even a different
object does not appear in the same pos. soon, and Earth-Sun relation =


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