Re: Late night - 28237 or MDS 1 x3 flashes ~ 25 second

From: Björn Gimle (
Date: Wed Dec 21 2005 - 14:24:12 EST

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    Cylindrical objects (like rockets) usually tumble end-over,
    ie around an axis perpendicular to the long axis.
    That will cause two symmetrically timed flashes per rotation.
    In many cases, eg when the axis isn't exactly at right angles,
    or when the object is slightly conical, the two flashes
    occur slightly asymetrically in time,and the
    double period becomes very obvious.
    If the object has other symmetry, and/or more reflecting surfaces,
    analysis of flash timing and brightnesses of flashes can reveal
    the true period.
    I do many such analyses using my program SYNODIC.
    The name implies that since observer-satellite-Sun angle varies
    during an observation, the start and end flash do NOT mark
    an integer number of rotation periods (or even half periods).
    With a complex geometry, different surfaces can have slightly
    different periods, and they can vary during the pass, since
    the satellite apparent speed varies.
    Essentially, SYNODIC presents a graph of absolute
    times (cumulative laps) MODULO assumed period.
    This can easily be done with Excel or other programs.
    Varying the period leads to (nearly) horizontal bands
    of flash times, and then trying integer multiples or
    fractions can reveal fine asymmetries and synodic
    variation, and the "true" period.
    ----- Original Message ----- 
    From: "ykchia"
    > ...
    > What is the reason   reported timing which is x2 ( double) the 
    > fundamental timing.. and in this case x3 ( x3x8=24)... in general
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