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    Re: Azimuth line of position
    From: Andrés Ruiz
    Date: 2010 Dec 15, 12:02 +0100

    I want to thank to Antoine for giving me the pleasant opportunity to study this atypical case.

    The azimuth line of position is defined by the angle j and the distance e in the same way as in a Marcq LoP. The parameters of this line are calculated as follow:

     

    DroiteAzimuth( Zo, Zc,  h,  B, *e, *J )

    {

       a = sqrt(SQ(TAN(h)*SIN(Z))+SQ(TAN(B)-TAN(h)*COS(Z)));

          

       *e = (Zo-Zc)/a;

       *J = ACOS( TAN(h)*SIN(Z)/a );

    }

     

    A fix by a ZLop and a MSH LoP :

     

     

     

    An example (see LoPZ.png ).

    The azimuth has an error of -2º.

    The altitude LoP is:

    15/12/2010

    11:13:02 UT1

     

    Be = 43.316666 º =  43º 19.0'

    Le = -2.000000 º =  -2º  0.0'

     

    ALMANAQUE NAUTICO - NAUTICAL ALMANAC

    Sun

    GHA = 349.488640 º = 349º 29.3'

    Dec = -23.271530 º = -23º 16.3'

    SD  = 16.249596 '

    HP  = 0.148910 '

     

    CORRECCION DE LA ALTURA - ALTITUDE CORRECTION

    Limb: lower

    Ref: Sea Horizon

    Hs = 22.1000 º =  22º  6.0'

    ie = 0.0000 '

    heas = 2.5000 m

    T = 10.0000 ºC

    P = 1010.0000 hPa

    Hoi = 22.1000 º

    dip = 0.0464 º

    Ha = 22.0536 º =  22º  3.2'

    R = 0.0400 º

    OB = -0.00000668 º

    HP = 0.0025 º

    PA = 0.00229358 º

    SD  = 0.2708 º

    Aug = 0.00000440 º

    SDag = 16.249860 '

    Ho = 22.2868 =  22º 17.2'

     

     

    DETERMINANTE DE LA RECTA DE ALTURA - Marcq St Hilaire LoP

    LHA = 347.488640 º = 347º 29.3'

    Hc = 22.4245 º =  22º 25.5'

    Z = 167.6 º

    p = Ho-Hc = -0.137706 º = -8.262343 '

     

    and the azimuth line is.

    a = 1.133497

    e = -1.764452

    J = 87.884208

     

    Regards
    --
    Andrés Ruiz
    Navigational Algorithms
    http://sites.google.com/site/navigationalalgorithms/

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