Re: SPAM::Re: iridium 90 disappoints

From: rfenske@swri.org
Date: Fri Sep 23 2005 - 18:28:48 EDT

  • Next message: Peter Wakelin: "SATOBS 2005 September 23-24"

    On Fri, 23 Sep 2005, Gerhard HOLTKAMP wrote:
    
    > Iridium 90 is 100 km below the operational Iridium orbits. I guess it acts as
    > a spare. Therefore its attitude does not have to be as tightly controlled as
    > those of the operational Iridium sats. A small change in attitude can lead to
    > a significant change in flare magnitude.
    
     	The operational ones have small orientation deviations also.  Since 
    the central ellipse on the ground where the main reflection falls is so small
    even deviations like +-0.1 or 0.2 deg can make a big difference in brightness 
    of the flare.  It's not uncommon for the flares to be fainter or brighter 
    than predicted.
    
    
    Robert Fenske, Jr.   rfenske@swri.edu    Sw     |The Taming the C*sm*s series:
    Southwest Research Institute            /R---\  |
    Signal Exploitation & Geolocation Div  | I    | |"The Martian canals were the
    San Antonio,Texas USA  ph:210-522-3931  \----/  | Martians' last ditch effort."
    
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