Re: DSS image- Almost certainly a single airplane and not 3

From: George Roberts (gr@gr5.org)
Date: Sun Jun 11 2006 - 10:40:24 EDT

  • Next message: Kevin Fetter: "next leo sat launch"

    ----- Original Message ----- 
    From: "Tony Beresford" <dberesford@adam.com.au>
    > The three streaks that dominate the picture are out of focus. you can even
    > see the dark centre that you would see with an out of focus image
    > in a telescope with a central obstruction. That strengthens the aeroplane
    > suggestion
    
    
    The field of view is about 1 degree by the way and up is north.  So the streaks
    can't be from a fixed object.
    
    I agree that the 3 streaks are out of focus objects and that they must be much 
    closer to the telescope than the stars but I think that an airplane wouldn't 
    normally be that blurry.  To be that blurry the object is probably only 100 to
    500 feet from the telescope.  It can't be birds or balloons because whatever it was
    seems to be very brightly lit.
    
    Instead I am convinced that all 3 streaks are from a single pass of one airplane.
    You can even see a flash in part of one of the streaks from a strobe.  The outer
    two streaks are wing tips and the central one is from nose, tail or fuselage.  One
    wing tip would be red and the other would be green (right/starboard).  Thus the
    different brightnesses.  This implies the plane was flying upward (north) in the picture
    assuming the red light registered brighter (assuming they used a red filter to
    highlight nebulae).  It also assumes that the strobe comes on fast and fades out
    more slowly.  The uneven spacing is probably because the central light isn't on
    center of the fuselage - maybe we are seeing cabin lights from one side of the plane
    or the light from only one side of the fuselage.
    
    - George Roberts
    http://gr5.org
    
    -------------------------------------------------------------------------
    Subscribe/Unsubscribe info, Frequently Asked Questions, SeeSat-L archive:  
    http://www.satobs.org/seesat/seesatindex.html
    



    This archive was generated by hypermail 2b29 : Sun Jun 11 2006 - 10:47:49 EDT