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* Transform Galactic Coordinate to B1950 FK4
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* palGe50( double dl, double db, double *dr, double *dd );
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* Galactic longitude (radians)
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* Galactic latitude (radians)
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* dr = double * (Returned)
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* dd = double * (Returned)
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* Transformation from IAU 1958 galactic coordinates to
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* B1950.0 'FK4' equatorial coordinates.
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* TIMJ: Tim Jenness (JAC, Hawaii)
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* {enter_new_authors_here}
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* - The equatorial coordinates are B1950.0 'FK4'. Use the routine
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* palGaleq if conversion to J2000.0 coordinates is required.
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* - Blaauw et al, Mon.Not.R.Astron.Soc.,121,123 (1960)
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* {enter_further_changes_here}
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* Copyright (C) 2012 Science and Technology Facilities Council.
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* All Rights Reserved.
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation; either version 3 of
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* the License, or (at your option) any later version.
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* This program is distributed in the hope that it will be
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* useful, but WITHOUT ANY WARRANTY; without even the implied
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* warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
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* PURPOSE. See the GNU General Public License for more details.
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
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* {note_any_bugs_here}
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void palGe50 ( double dl, double db, double * dr, double * dd ) {
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* L2,B2 system of galactic coordinates
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* P = 192.25 RA of galactic north pole (mean B1950.0)
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* Q = 62.6 inclination of galactic to mean B1950.0 equator
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* R = 33 longitude of ascending node
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* Equatorial to galactic rotation matrix
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* The Euler angles are P, Q, 90-R, about the z then y then
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* +CP.CQ.SR-SP.CR +SP.CQ.SR+CP.CR -SQ.SR
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* -CP.CQ.CR-SP.SR -SP.CQ.CR+CP.SR +SQ.CR
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double rmat[3][3] = {
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{ -0.066988739415,-0.872755765852,-0.483538914632 },
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{ +0.492728466075,-0.450346958020,+0.744584633283 },
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{ -0.867600811151,-0.188374601723,+0.460199784784 }
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double v1[3], v2[3], r, d, re, de;
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/* Spherical to cartesian */
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iauS2c( dl, db, v1 );
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/* Rotate to mean B1950.0 */
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iauTrxp( rmat, v1, v2 );
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/* Cartesian to spherical */
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iauC2s( v2, &r, &d );
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/* Introduce E-terms */
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palAddet( r, d, 1950.0, &re, &de );
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/* Express in conventional ranges */