Re: Iridium flare droughts

Robert G Fenske Jr (fenske@rgfpc.electro.swri.edu)
Fri, 20 Feb 1998 08:33:04 -0600 (CST)

On Fri, 20 Feb 1998, Bjoern Gimle wrote:

> I have also run a prediction for two different locations, four years for
> a few satellites, and one year for a complete 66-sat config, and found
> only random fluctuations, except the shift day/night flares, and a
> latitude factor of 1/cos and a little more.

	In January, I calculated a year's worth of predictions for the
then-current constellation for 90W longitude and every 5 deg of latitude
from 0N to 90S.  Below about 65S there wasn't much seasonal variation
except for the obvious scarcity in winter due to the Sun being below the
horizon much of the time (esp at thepoles).  Above 65S I found a paucity
of flares in March and August with the most in June and December, i.e. a
2-cycle sinusoidal variation.  This variation flattened out for lats close
to the equator, where the was no variation (other than random fluctuations).
I didn't check if the counts varied as 1/cos(lat), but I can say the poles
have on the order of 100x the # flares that the equator does.


Robert Fenske, Jr.   rfenske@swri.edu    Sw     |The Taming the C*sm*s series:
Southwest Research Institute            /R---\  |
Signal Exploitation & Geolocation Div  | I    | |"The Martian canals were the
San Antonio,Texas USA  ph:210-522-3931  \----/  | Martians' last ditch effort."