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    Refraction
    From: Marcel Tschudin
    Date: 2005 Aug 4, 13:48 +0300

    Hello

     

    While searching with Google, I came across this mail list. May be some one out here may be able to help me answering the following question:

     

    How do refraction values for negative elevations have to be calculated, such as e.g. the horizon from a plane? (I am interested in the range of 0° to approx. –5°.)

     

    Is Bennett’s approximation also valid for negative elevations? If not, what other approximation formulae should be used, or, where can one find some benchmark values?

     

    I am interested in formulae for both, refraction from apparent position and from physical position.

     

    Thank you for any input to my problem.

     

    Marcel

       
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