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    Re: Navy MK 5 Octant Using Natural Horizon
    From: Greg Rudzinski
    Date: 2012 May 2, 16:22 -0700


    Any spread less than 10' is good when using a bubble octant.

    moa = minutes of arc which is redundant when ' is used. Sorry for confusion there.

    Aviators use (Hp) for pre-calculated altitude which allows for immediate azimuth and intercept determination.

    Yes "A" for away and "T" for toward is standard.

    Height of eye is generally in feet so it is a good idea to put ft. after and not '

    As promised follows a series of observations using a Tamaya Jupiter equipped with a 7 x 35 mm scope.

    Sun lower limb
    H.E. 9 ft.
    I.C. -0.3'
    aLat. 34* 10.2' N
    aLon. 119* 14.0'

    UT 5/2/2012
    UT 21:03:27 Hs 65* 34.8' INT 0.3' T
    :09:13 64* 43.3' 0.1' T
    :11:43 64* 20.8' 0.6' T (maximum)
    :12:42 64* 11.6' 0.5' T
    :13:24 64* 4.8' 0.2' T
    :14:30 63* 54.2' 0.0 (minimum)
    :15:25 63* 45.7' 0.1' T
    :16:19 63* 37.3' 0.3' T
    :17:21 63* 27.6' 0.5' T
    :18:21 63* 18.1' 0.6' T

    Avg 0.3' T Spread 0.6'

    Sight reductions by Pilot Navigator Software version 6.9


    This data set is better than expected due to an excellent sharp horizon. Typically a spread of 1' is good. Average intercepts vary as the result of measured accuracies of H.E. , I.C., and time.

    Greg Rudzinski

    P.S. Dave Walden has no excuses now that he just acquired a Tamaya Jupiter ;-) Clear skies and good shooting Dave :)
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