Photograph of Columbia in daylight?

From: Tom Wagner (sciteach@mchsi.com)
Date: Sat Mar 01 2003 - 02:20:44 EST

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    On 2/25 Robert Fenske, Jr. posted the following URL
    http://spaceflightnow.com/shuttle/sts107/030225amos/visible.html which shows
    a remarkable image of the Columbia taken on Jan 28. The telescope that took
    the picture was on Maui at an observatory with a geodetic altitude of 3,058
    meters. After much searching I finally located the observatory's
    coordinates. They are 156:15:29 West and 20:42:31 North. The UTC offset
    is -10 hours.
    
    I looked at the pictures and noticed what looked like low angle direct
    sunlight on the nose and other places and what appeared to be a low contrast
    illumination that looked like what would be caused by "earth shine" on the
    rest of the craft. That made me wonder if this picture was shot during
    daylight in what would have been, as seen from that observatory's altitude,
    a deep blue sky. On the picture itself is the following information: STS-107
    28 Jan 2003  21:49Z. If the 21:49Z means 21:49 UTC the photograph was taken
    at 11:49 AM local time, right?? That time I do not think would not provide
    the correct angle of direct sunlight.
    
    In an attempt to double check the time that the picture could have been
    taken I looked up an archived TLE for the Shuttle that day and plugged it
    into my planetarium software. The TLE I used follows:
    1 27647U 03003A   03028.25000000  .00065526  72042-5  11773-3 0   506
    2 27647  39.0185 151.7164 0008975 103.0922 196.3708 16.00992267  1855
    
    I ran a check and determined that the best possible pass over Maui was
    around 16:46:00 local time.  At that time the shuttle was generally SE and
    was about 57 degrees in altitude; the sun was also at the proper angle for
    producing the glare that the image shows and the earth below would have been
    well illuminated.
    
    I welcome comments on my analysis. I may have made a serious error because
    this type of analysis is quite new to me.
    
    In doing the research I have learned much about the satellite tracking
    systems at the Maui site. They are impressive to say the least. If you are
    interested you can begin by doing a Google search for "MAUI SPACE
    SURVEILLANCE SYSTEM (MSSS) SENSORS" then click on "cache" otherwise you will
    get an error message.
    
    A system called GEMINI can produce images of satellites even in daylight
    conditions. There you have it! That must be what they did when photographing
    the Shuttle. Some of the telescopes are even fitted with lasers that can
    illuminate LEO satellites during the time they are in shadow!
    
    There is also a telescopic setup called the, "Contrast Mode Photometer
    (CMP)" that is very impressive. The article reads, "because of its large,
    twenty stellar magnitude dynamic range, the CMP is particularly useful for
    observing specular glint measurements from artificial satellites illuminated
    by the sun. An example of a photometric signature obtained from a
    geostationary satellite is shown in Figure 5. Much can be learned about the
    configuration and dynamics of an unknown satellite by studying the glints in
    CMP signatures. Uniform repetition of glints might indicate rotation of the
    object which can indicate that it is spin stabilized or has gone unstable.
    Motions and configuration can also be determined through analysis of the
    more slowly varying diffuse component of an optical signature."
    
    The manual for the AMOS telescope system is very informative too. It can be
    obtained here: http://www.maui.afmc.af.mil/AMOS/AMOS_UsersManual_02.pdf It's
    only 16MB and 117 pages long! :~)
    
    One last thing for any stereo enthusiasts. The last of the three visible
    light pictures of the shuttle can be stereofused with the first or second
    image to produce a crude 3D image. I placed the last image to the right of
    the other ones and used the cross-eyed method to see the third dimension.
    
    Clear skies!
    
    Tom
    Iowa
    USA
    .....
    
    
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