Re: Spot 3 (93- 61 A)

Björn Gimle (
Mon, 19 Apr 1999 19:53:32 +0200

>I've been meaning to ask this question to the BWGS observers for some time 
>now.  For two objects I've had a problem in resolving how to report the 
>including some very strange looking flashes.  How does one report these 
>observations with some semblance of consistency?
>the average flash period based on the total time it doesn't accurately 
>reflect the true flash period.   If I truncate the PPAS report to include the 
>time when both flashes were visible it doesn't capture the total visibility 
>Any advice?
Though still very rudimentary, I want to propose my graphical method.
I enter each timing into a program, then guess a flash period. The
program computes the time difference of each flash from the nearest
multiple of the assumed period. Usually diagonal bands are visible,
and are levelled by changing the period. Parallell bands with non-
uniform distances (not all integer fractions of the period) indicate
secondary flashes. If random errors cause markers to spill over top-to
bottom of chart, a bias is added.

The program could be enhanced to use specified markers for some
individual flashes, if your observations include (some) flash characte-
ristics or magnitudes, which would make identification of the true
period easier.

I first used it to prove a strange, but very definitive, S-shaped change
of flash period during a pass of a newly launched Zenith-2 rocket.
I call the program 'synodic', though I could not explain this effect
as synodic.

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