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Annotation of researchv10no/cmd/sky/aberr.c, revision 1.1

1.1     ! root        1: #include "sky.h"
        !             2: 
        !             3: aberr()
        !             4: {
        !             5: 
        !             6:        double lsun, ljup, lsat;
        !             7:        double msun, mven, mjup, msat;
        !             8:        double dmoon;
        !             9:        double c,d,k,e;
        !            10: 
        !            11: /*
        !            12:        To find the aberration, it is necessary to compute
        !            13:        the velocity of the observer in an inertial frame.
        !            14: 
        !            15:        This program does the computation for the center
        !            16:        of the earth w/r the center of mass of the Solar System
        !            17:        and includes enough terms to limit the error to
        !            18:        about 0".003.
        !            19: 
        !            20:        uses capt, eday
        !            21:        sets xdot, ydot, zdot
        !            22: */
        !            23: 
        !            24:        lsun = 279.696678 + 0.9856473354*eday + .000300*capt2;
        !            25:        ljup = 237.942344 + .083129433*eday;
        !            26:        lsat = 266.56527 + 0.03351336*eday;
        !            27: 
        !            28:        msun = 358.475845 + .9856002670*eday - .000150*capt2;
        !            29:        mven = 212.603219 + 1.602130154*eday;
        !            30:        mjup = 225.22165 + .083085369*eday;
        !            31:        msat = 175.47630 + 0.03345972*eday;
        !            32:        dmoon = 350.737681+12.1907491914*eday-.001436*capt2;
        !            33: 
        !            34:        lsun = lsun * radian;
        !            35:        ljup = ljup*radian;
        !            36:        lsat = lsat*radian;
        !            37:        msun = msun*radian;
        !            38:        mven = mven*radian;
        !            39:        mjup = mjup*radian;
        !            40:        msat = msat*radian;
        !            41:        dmoon = fmod(dmoon,360.)*radian;
        !            42: 
        !            43: /*
        !            44:        Discover the velocity of the Earth around the Sun.
        !            45: */
        !            46: 
        !            47:        xdot =
        !            48:         -20.4916*sin(lsun)
        !            49:         - 0.3433*sin(lsun+msun)
        !            50:         + 0.0009*capt*sin(lsun+msun)
        !            51:         - 0.0065*sin(lsun+2.*msun)
        !            52:         - 0.0007*sin(4.159+2.*mven-2.*msun+lsun)
        !            53:         - 0.0007*sin(4.7042+msun-mjup+lsun);
        !            54: 
        !            55:        ydot =
        !            56:         20.4901*cos(lsun)
        !            57:         + 0.3433*cos(lsun+msun)
        !            58:         - 0.0009*capt*cos(lsun+msun)
        !            59:         + 0.0065*cos(lsun+2.*msun)
        !            60:         + 0.0007*cos(4.159+2.*mven-2.*msun+lsun)
        !            61:         + 0.0007*cos(4.7042+msun-mjup+lsun);
        !            62: 
        !            63: /*
        !            64:        Discover the velocity of the Earth around the center
        !            65:        of the Earth-Moon system.
        !            66: */
        !            67: 
        !            68:        xdot = xdot
        !            69:        - 0.0079*sin(lsun+dmoon);
        !            70: 
        !            71:        ydot = ydot
        !            72:         + 0.0079*cos(lsun+dmoon);
        !            73: 
        !            74: /*
        !            75:  *     Discover the velocity of the sun about the center of mass.
        !            76:  */
        !            77: 
        !            78:        xdot = xdot
        !            79:         - 0.0086*sin(ljup)
        !            80:         - 0.0004*sin(ljup+mjup)
        !            81:         - 0.0019*sin(lsat)
        !            82:         - 0.0001*sin(lsat+msat);
        !            83: 
        !            84:        ydot = ydot
        !            85:         + 0.0086*cos(ljup)
        !            86:         + 0.0004*cos(ljup+mjup)
        !            87:         + 0.0019*cos(lsat)
        !            88:         + 0.0001*cos(lsat+msat);
        !            89: 
        !            90: /*
        !            91:  *     Compute aberrational day numbers just for fun.
        !            92:  */
        !            93: 
        !            94:        k = 20.496;
        !            95:        e = .01675104 - 4.180e-5*capt - 1.26e-7*capt2;
        !            96:        c = -ydot*cos(obliq) - k*e*cos(lsun-msun+pi)*cos(obliq);
        !            97:        d = xdot - k*e*sin(lsun-msun+pi);
        !            98: 
        !            99:        if(flags&GOOBIE){
        !           100:                printf("C: %.4f  D: %.4f\n", c, d);
        !           101:        }
        !           102: 
        !           103: /*
        !           104:        Convert to absolute velocity (v/c).
        !           105: */
        !           106: 
        !           107:        xdot = xdot * radsec;
        !           108:        ydot = ydot * radsec;
        !           109:        zdot = 0.;
        !           110: }

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