{Spam?} Re: Lacrosse 4 _USA-152) (26473 2000-047-A) telescopic OBS

From: Ralf Vandebergh (ralf.vandebergh@home.nl)
Date: Wed Aug 04 2010 - 11:01:36 UTC

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    With ' the satellites' was meant  the Lacrosses of course
    
    
    
    > Thanks for the information. The satellites all seem to show an equal
    > appearance under comparing conditions; the round shape mostly when it
    passes not
    > overhead but is seen under a larger angle. This drawing of a Lacrosse
    shows clearly
    > a big dish antenenna:
    > http://spacefacts.de/graph/drawing/drawings2/sts-27_lacrosse.jpg
    >
    > Solar panels of a satellite are in much cases not well visible. For
    example:
    > I captured many passes of the Progress M-04M last june and just on
    > a few occasions, the viewing angle enabled to see the solar panels.
    >
    > Ralf
    >
    > ----- Original Message -----
    > From: "Ted Molczan" <ssl3molcz@rogers.com>
    > To: <SeeSat-L@satobs.org>
    > Sent: Monday, August 02, 2010 9:04 PM
    > Subject: {Spam?} RE: {Spam?} Lacrosse 4 _USA-152) (26473 2000-047-A)
    > telescopic OBS
    >
    >
    > Ralf Vandebergh wrote:
    >
    > > Here are some observations of Lacrosse 4 spacecraft from last evening
    > > during a 74 culm NW pass:
    > >
    > > http://img535.imageshack.us/img535/1997/lacrosse410010823342931.jpg
    > >
    > > The drop-shape is a typical behave of a Lacrosse satellite seen from
    > > a certain angle. Here is an older image from a professional telescope
    > > of the Lacrosse 1:
    > >
    > > http://www.fas.org/spp/military/program/track/lacr1_2.jpg
    >
    > Three years ago, Allen Thomson alerted the list to more recent
    professional
    > imagery, by Russia's
    > Altay Optical-Laser Center:
    >
    > http://satobs.org/seesat/Jun-2007/0275.html
    >
    > Images of Lacrosse 2 and other satellites are on slide 14 of the following
    > presentation at the site
    > in Allen's post:
    >
    > http://www.niipp-moskva.ru/ppt/booklet_IPIE_int.ppt
    >
    > Allen's translation revealed that the scale is the short white bar within
    > the caption on the left
    > edge of the image on slide 14; the length of that bar is 1 arc sec.
    >
    > I will take a stab at calculating the size of what appears to be the
    > satellite's dominant feature: a
    > dish antenna (corrections/improvements welcome!):
    >
    > The scale bar appears to be about 22 pixels long, and the dish of the
    middle
    > Lacrosse image is about
    > 34 pixels wide; therefore, 1*34/22 = 1.5 arc sec for the dish.
    >
    > On the pass on which that image was taken, Lacrosse's closest range was
    816
    > km, which would result
    > in ~4 m per arc sec, which makes the dish at least 1.5 x 4 m = 6 m wide.
    Of
    > course, the image range
    > could have been somewhat further, up to perhaps 1000 km, in which case, 1
    > arc sec = 4.9 m, which
    > would make the dish about 7.4 m.
    >
    > The plane of the dish appears not to be perpendicular to the observer, so
    > perhaps its real diameter
    > is somewhat greater, but not by much (I guess).
    >
    > Further reading: Allen's source book on the Altay Optical-Laser Center
    >
    > http://www.fas.org/spp/military/program/track/altay.pdf
    >
    > Ted Molczan
    >
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    >
    
    
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