Re: Intelsat 4A6 Rk

From: Björn Gimle (b_gimle@algonet.se)
Date: Sat Jul 20 2002 - 10:21:32 EDT

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    In my vocabulary, synodic refers to the fact that the observed flash period is
    different from the true siderial rotation period, and thus (normally) varies
    during a pass, as the angular velocity and aspects
    Sat-Sun-Axis-Reflector-Observer varies.
    
    With more than one reflecting surface (also the two "sides" of a tumbling
    rocket), the synodic periods can vary "independently" of each other. The fact
    that other surfaces' reflections appear/disappear or change their appearance
    should perhaps also be termed 'synodic'.
    
    If you have retained all cumulative (or lap) stopwatch readings, I would like to
    visualize them with my 'SYNODIC' program.
    
    -- bjorn.gimle@tietotech.se (office)                         --
    -- b_gimle@algonet.se (home)  http://www.algonet.se/~b_gimle --
    -- COSPAR 5919, MALMA,    59.2576 N, 18.6172 E, 23 m         --
    -- COSPAR 5918, HAMMARBY, 59.2985 N, 18.1045 E, 44 m         --
    
    > Yesterday , I made an interessant observation of  Intelsat 4A6 Rk (78035B
    > 10779). First, I counted 50 flashes, and during this observation, I remarked
    > that two consecutive flashes had not the same aspect : one was more bright
    > and sharp, the other one was smoother, like a flare. It suggested that I was
    > counting the HALF period.
    > 3' 52.84" / 50 = 4.66" * 2 = 9.32" for the whole period
    >
    > Then I used my stop watch and I found an asymetrical period : 4.73" between
    > the sharp flash and the smoother; 4.58" for the other interval
    >
    > But at the end of this second sequence of measures, the two periods were
    > less and less different and suddenly (at 22:10 UT), a little flash appeared
    > short after the sharp one : F f A F with following intervals :
    >                                                            F-f = 1.28"
    >                                                            f-A = 3.35"
    >                                                            A-F = 4.69"
    > which gives again a period of  1.28+3.35+4.69 = 9.32"
    > How can be explained this modification of the pattern?  synodic effect?
    
    
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