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    Re: Refraction
    From: George Huxtable
    Date: 2008 Jul 5, 00:03 +0100

    About the refraction predictions in which the Nautical Almanac tables are 
    based, I wrote-
    
    "Indeed, the Hohenkerk / Sinclair predictions are based on a rather simple
    model of the atmosphere, in which the air temperature falls by 6.5�C from
    sea level to 11km up (that is, by 71.5�C), and then stays constant at that
    value right up to the limit of the atmosphere, taken to be 80 km. "
    
    And in that, I missed some vital words. I should have read-
    
    "Indeed, the Hohenkerk / Sinclair predictions are based on a rather simple
    model of the atmosphere, in which the air temperature falls by 6.5�C per 
    kilometre from sea level to 11km up (that is, by 71.5�C), and then stays 
    constant at that value right up to the limit of the atmosphere, taken to be 
    80 km. "
    
    Sorry.
    
    George.
    
    contact George Huxtable at george@huxtable.u-net.com
    or at +44 1865 820222 (from UK, 01865 820222)
    or at 1 Sandy Lane, Southmoor, Abingdon, Oxon OX13 5HX, UK. 
    
    
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