1 files changed, 118 insertions, 0 deletions
diff --git a/ast/pal/palGaleq.c b/ast/pal/palGaleq.c
new file mode 100644
index 0000000..d0da1ee
--- /dev/null
+++ b/ast/pal/palGaleq.c
@@ -0,0 +1,118 @@
+/*
+*+
+*  Name:
+*     palGaleq
+
+*  Purpose:
+*     Convert from galactic to J2000.0 equatorial coordinates
+
+*  Language:
+*     Starlink ANSI C
+
+*  Type of Module:
+*     Library routine
+
+*  Invocation:
+*     void palGaleq ( double dl, double db, double *dr, double *dd );
+
+*  Arguments:
+*     dl = double (Given)
+*       Galactic longitude (radians).
+*     db = double (Given)
+*       Galactic latitude (radians).
+*     dr = double * (Returned)
+*       J2000.0 RA (radians)
+*     dd = double * (Returned)
+*       J2000.0 Dec (radians)
+
+*  Description:
+*     Transformation from IAU 1958 galactic coordinates to
+*     J2000.0 equatorial coordinates.
+
+*  Authors:
+*     PTW: Pat Wallace (STFC)
+*     TIMJ: Tim Jenness (JAC, Hawaii)
+*     {enter_new_authors_here}
+
+*  Notes:
+*     The equatorial coordinates are J2000.0.  Use the routine
+*     palGe50 if conversion to B1950.0 'FK4' coordinates is
+*     required.
+
+*  See Also:
+*     Blaauw et al, Mon.Not.R.Astron.Soc.,121,123 (1960)
+
+*  History:
+*     2012-02-12(TIMJ):
+*        Initial version with documentation taken from Fortran SLA
+*        Adapted with permission from the Fortran SLALIB library.
+*     {enter_further_changes_here}
+
+*  Copyright:
+*     Copyright (C) 1998 Rutherford Appleton Laboratory
+*     Copyright (C) 2012 Science and Technology Facilities Council.
+*     All Rights Reserved.
+
+*  Licence:
+*     This program is free software: you can redistribute it and/or
+*     modify it under the terms of the GNU Lesser General Public
+*     License as published by the Free Software Foundation, either
+*     version 3 of the License, or (at your option) any later
+*     version.
+*
+*     This program is distributed in the hope that it will be useful,
+*     but WITHOUT ANY WARRANTY; without even the implied warranty of
+*     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+*     GNU Lesser General Public License for more details.
+*
+*     You should have received a copy of the GNU Lesser General
+*     License along with this program.  If not, see
+*     <http://www.gnu.org/licenses/>.
+
+*  Bugs:
+*     {note_any_bugs_here}
+*-
+*/
+
+#include "pal.h"
+#include "pal1sofa.h"
+
+void palGaleq ( double dl, double db, double *dr, double *dd ) {
+
+  double v1[3];
+  double v2[3];
+
+/*
+*  L2,B2 system of galactic coordinates
+*
+*  P = 192.25       RA of galactic north pole (mean B1950.0)
+*  Q =  62.6        inclination of galactic to mean B1950.0 equator
+*  R =  33          longitude of ascending node
+*
+*  P,Q,R are degrees
+*
+*  Equatorial to galactic rotation matrix (J2000.0), obtained by
+*  applying the standard FK4 to FK5 transformation, for zero proper
+*  motion in FK5, to the columns of the B1950 equatorial to
+*  galactic rotation matrix:
+*/
+  double rmat[3][3] = {
+    { -0.054875539726,-0.873437108010,-0.483834985808 },
+    { +0.494109453312,-0.444829589425,+0.746982251810 },
+    { -0.867666135858,-0.198076386122,+0.455983795705 }
+  };
+
+  /* Spherical to Cartesian */
+  eraS2c( dl, db, v1 );
+
+  /* Galactic to equatorial */
+  eraTrxp( rmat, v1, v2 );
+
+  /* Cartesian to spherical */
+  eraC2s( v2, dr, dd );
+
+  /* Express in conventional ranges */
+  *dr = eraAnp( *dr );
+  *dd = eraAnpm( *dd );
+
+}