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    Re: Longhand Sight Reduction
    From: Hanno Ix
    Date: 2014 Nov 24, 17:04 -0800

    here is a haversine table I just made that fits on 2 pages. This compression was possible because it proceeds in steps of 2 arc min ea. from 0 to 180 deg. For interpolation to 1 arc min you just take the value halfway between 2 steps. This is very easily done mentally.

    Also, there are highlighted visual guides that help you finding the correct location on the table quickly.

    I guess,Greg Rudzinski will explain to you his scheme teasingly called the "Rudzinski Index Card".


    On Mon, Nov 24, 2014 at 3:21 PM, Greg Licfi <NoReply_GregLicfi@fer3.com> wrote:
    Hi All,
        I have been following the haversine discussion with great interest.
    One post said that everything (formulas I guess) fit on a 3X5 card (?)
    What about the haversign table?
    I am thinking of making my own tables; I wonder to what resolution
    would you expect to go down to?

     On 11/23/2014 04:06 PM, Greg Rudzinski wrote:


    The formula varient that you show is actually what I used to format the index card reduction. It works well to save space. For same name N=hav(L-D),  P=hav(L+D). For contrary name N=hav (L+D), P=hav (L-D). For calculator reductions  Hc= Arc Sin [1-2(x),   x=N+(1-Q)*havLHA.

    I prefer to us different letters where n=(L+/-d),m=(L+/-d), P=(1- (n+m))*havLHA, ZD=Arc hav(n+P). This way when Bowditch is consulted there is better agreement.

    Greg Rudzinski

    From: Hanno Ix
    Date: 2014 Nov 23, 10:10 -0800

    there is a form of the hav-Doniol some people might prefer.
    Mathematically, there is no difference to the original formulation.
    Here it is:


                   define:   N  =  hav( L - D );

                   define:   P  =   hav( L +D );

                   define:   Q  =  N + P;


                   hav(s2s)  =  N + ( 1 - Q )* hav(LHA);


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