geostationary movers.

From: John Locker (
Date: Thu Oct 21 2004 - 13:26:33 EDT

  • Next message: "Re: geostationary movers."

    Hi everyone....
    Earlier in the year I captured three geo movers on film.
    Two were unid , but the third I actually targeted , so we know 100% that it
    was. (Eut W3A )
    Given that  we have one "control" video..... , W3A , we can compare the
    movement to the other two in order to possibly ascertain if the unids were
    in controlled drift , or graveyard orbit .
    Fortunately , when capturing the three movers , I used 10 sec exposures so I
    can compare like for like.
    I took four consecutive frames from each capture , all at 640 x 480 ....
    applied a simple grid to each , then cropped out the movement over the 40
    sec period.
    The grid square used gives about 5 km per square in the arc.
    Interestingly  each of the movers , including the
    control item , are drfiting at about the same speed , relative to birds in
    geo orbit...and in the same direction ... west to east.
    It equates to about 7.5km / minute.....450 km / hour ( relative to stable
    geosats )
    At the time it was thought that the two unids were possibly in graveyard
    orbit or possibly debris (although they were not flashing)
    However , my findings point to the possibility that these were in fact in
    conrolled drift  , like W3A
    Keps for W3A during the drift period indicate it was about 50 km below the
    geo belt.
    At this point , I get lost with the maths...yet again ;O)
    If my relative velocity of 450 km / hour is right , does this compute to an
    approximate orbit of 50 km or so below the geo belt?
    Also , does anyone know what the tolerance is ( in km ) for a geosat to
    remain stable in orbit ?
    (I'm assuming that different topgraphy below their lots will have a marginal
    affect on orbital height )
    Any thoughts ?
    Thanks ,
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