RE: Multipoint observations? And stealthy/disappearing Lacrosse birds

From: Michael & Caroline Rice (mcrice@bigpond.com)
Date: Fri Feb 01 2008 - 06:56:34 UTC

  • Next message: David Brierley: "DMB Some obs February 1 a.m."

     
    A newbie to the list but here's my two bob's worth.
    
    I was thinking that multipoint observations might answer some of the
    questions about the "stealth" or "disappearing" behaviour of satellites like
    Lacrosse 5 (see the January archives under "light curve from satellite
    trail", or Bjorn's post copied below).
    
    If observers separated in longitude ie east/west could demonstrate
    simultanaeous dimming, that would support the "shadow" (or, if you prefer,
    "shield") theory; if an observer to the solar side could see the satellite
    while the shadow side observer saw dimming, that would support the
    "illuminated box" theory.
    
    Ideally, two or more observers of similar latitude but separated in
    longitude with the satellite passing between. If more northerly/southerly
    observers were also available, and light/dark/flare timings were different,
    deductions could be made about the satellite's shape or bright/dark sides.
    
    But not by me. I have enough trouble telling east from south... 
    
    Michael
    
    -----Original Message-----
    From: John A. Dormer 2 [mailto:jad@texas.net] 
    Sent: Friday, 1 February 2008 2:37 PM
    To: Seesat List
    Subject: Multipoint observations?
    
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    Scott Campbell and I both live in Texas, and in an unlikely physical
    arrangement. I'm 183km to the north of him and less than 100 meters west of
    his site. Is there any use for this arrangement for optical observation?
    
    I know for some types of radio work it'd be useful, as a very large
    synthetic aperture, but I don't know an inexpensive way to do that sort of
    thing at the moment.
    
    	John
    
    --------older message from the archives
    
    Without knowing the exact layout, IMHO any satellite with a large
    antenna/panel monted on some boom outside the spacecraft
    can get into an attitude where we see the dark backside of
    the panel, and/or the panel shadows the satellite.
    
    Likewise, more or less box-shaped satellites can in some
    attitudes display only shadowed surfaces to the observers,
    and there may be no large protrusions that cast even
    secondary light onto these surfaces.
    
    Just my 5c
    
    /Björn
    
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