예제 #1
0
        /// <summary>
        /// Converts galactical coodinates to equatorial, for equinox B1950.0.
        /// </summary>
        /// <param name="gal">Galactical coodinates.</param>
        /// <returns>Equatorial coodinates, for equinox B1950.0.</returns>
        public static CrdsEquatorial ToEquatorial(this CrdsGalactical gal)
        {
            CrdsEquatorial eq = new CrdsEquatorial();

            double l_l0   = Angle.ToRadians(gal.l - 123.0);
            double delta0 = Angle.ToRadians(27.4);
            double b      = Angle.ToRadians(gal.b);

            double Y        = Math.Sin(l_l0);
            double X        = Math.Cos(l_l0) * Math.Sin(delta0) - Math.Tan(b) * Math.Cos(delta0);
            double sinDelta = Math.Sin(b) * Math.Sin(delta0) + Math.Cos(b) * Math.Cos(delta0) * Math.Cos(l_l0);

            eq.Alpha = Angle.To360(Angle.ToDegrees(Math.Atan2(Y, X)) + 12.25);
            eq.Delta = Angle.ToDegrees(Math.Asin(sinDelta));
            return(eq);
        }
예제 #2
0
        /// <summary>
        /// Converts equatorial coordinates (for equinox B1950.0) to galactical coordinates.
        /// </summary>
        /// <param name="eq">Equatorial coordinates for equinox B1950.0</param>
        /// <returns>Galactical coordinates.</returns>
        public static CrdsGalactical ToGalactical(this CrdsEquatorial eq)
        {
            CrdsGalactical gal = new CrdsGalactical();

            double alpha0_alpha = Angle.ToRadians(192.25 - eq.Alpha);
            double delta        = Angle.ToRadians(eq.Delta);
            double delta0       = Angle.ToRadians(27.4);

            double Y    = Math.Sin(alpha0_alpha);
            double X    = Math.Cos(alpha0_alpha) * Math.Sin(delta0) - Math.Tan(delta) * Math.Cos(delta0);
            double sinb = Math.Sin(delta) * Math.Sin(delta0) + Math.Cos(delta) * Math.Cos(delta0) * Math.Cos(alpha0_alpha);

            gal.l = Angle.To360(303 - Angle.ToDegrees(Math.Atan2(Y, X)));
            gal.b = Angle.ToDegrees(Math.Asin(sinb));
            return(gal);
        }