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    Re: on orientation of an artificial horizon
    From: Gary LaPook
    Date: 2012 Jan 10, 22:40 -0800
    Just stand or sit with the mirror between you and the star. Preset your sextant to twice the Hc. Move towards or away from the mirror until you see you star in the mirror. Bring the sextant to your eye looking at the star's reflection in the AH. rock the sextant and you should find the star in the sextant horizon mirror.


    --- On Tue, 1/10/12, Alan S <alan202@verizon.net> wrote:

    From: Alan S <alan202@verizon.net>
    Subject: [NavList] on orientation of an artificial horizon
    To: NavList@fer3.com
    Date: Tuesday, January 10, 2012, 10:21 PM

    Bear with me on what might be a dumb question.

    With the Davis type ah, essentially a dish of water with wind shields, the instructions tell one to point the ah toward the sun so that the shadow is toward the observer, with no shadow along the side of the unit. With such positioning, proper orientation is obtained.

    Using a mirror type ah, mirror mounted on a leveling plate arrangement of whatever sort one came up with, the thing would be oriented as above described. The mirror type ah would have to be leveled.

    Shooting a star with a mirror ah, which has been mentioned I believe, one would "pre-calculate" the altitude and azimuth of the star, using a 2102-d or perhaps air navigation tables and point the ah down the appropriate compass heading, as there would be no shadow orientation possible. For a moon shot, location of the moon is obvious, and it's altitude can be roughly set on the sextant measuring with the height of one's fist at arms length, one fist equaling 10 degrees approximately.

    Corrections please, if necessary.

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