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    Re: Venus ex-mer backsight dipshort
    From: Greg Rudzinski
    Date: 2011 Jan 16, 11:49 -0800

    Jeremy,

    Good going on capturing the rare Venus ex-meridian dip short backsight.

    Dip short from 106 feet seems to be very sensitive to horizon distance estimation.
    -60.4' at 1.0 NM
    -48.5' at 1.25 NM
    Dropping the height of eye down would help a lot here.

    For this exercise a LOP is determined by a smartphone Palm CN program:
    Azimuth 190.1�
    Intercept 6.5' away

    This gives me something to compare the ex-meridian to.


    As Requested (Venus 8m 27s after M.P.)

    1. (a) = 1.9635(Cos7�16.3')(Cos18�30.0')/Sin(11�13.7') = 9.48

    2. Ex.corr. = 9.48(8.45)(8.45)/60 = 11.3'

    3. Dip short correction is -48.5' for a 1.25NM horizon from an H.E. of 106ft. *

    4. Latitude 7� 10.1' S (6.2 NM away)

    * an online calculator was used for the dip short calculation
    http://www.starpathdemos.com/bowditch/table14.htm

    Greg Rudzinski
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