Merge commit '7fde2daeed593684120d75de07598154f3ddaf2c' as 'ast'

1 files changed, 112 insertions, 0 deletions

diff --git a/ast/pal/palAddet.c b/ast/pal/palAddet.c
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+++ b/ast/pal/palAddet.c
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+/*
+*+
+*  Name:
+*     palAddet
+
+*  Purpose:
+*     Add the E-terms to a pre IAU 1976 mean place
+
+*  Language:
+*     Starlink ANSI C
+
+*  Type of Module:
+*     Library routine
+
+*  Invocation:
+*     void palAddet ( double rm, double dm, double eq,
+*                     double *rc, double *dc );
+
+*  Arguments:
+*     rm = double (Given)
+*        RA without E-terms (radians)
+*     dm = double (Given)
+*        Dec without E-terms (radians)
+*     eq = double (Given)
+*        Besselian epoch of mean equator and equinox
+*     rc = double * (Returned)
+*        RA with E-terms included (radians)
+*     dc = double * (Returned)
+*        Dec with E-terms included (radians)
+
+*  Description:
+*     Add the E-terms (elliptic component of annual aberration)
+*     to a pre IAU 1976 mean place to conform to the old
+*     catalogue convention.
+
+*  Authors:
+*     PTW: Pat Wallace (STFC)
+*     TIMJ: Tim Jenness (JAC, Hawaii)
+*     {enter_new_authors_here}
+
+*  Notes:
+*     Most star positions from pre-1984 optical catalogues (or
+*     derived from astrometry using such stars) embody the
+*     E-terms.  If it is necessary to convert a formal mean
+*     place (for example a pulsar timing position) to one
+*     consistent with such a star catalogue, then the RA,Dec
+*     should be adjusted using this routine.
+
+*  See Also:
+*     Explanatory Supplement to the Astronomical Ephemeris,
+*     section 2D, page 48.
+
+*  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) 1999 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 palAddet ( double rm, double dm, double eq, double *rc, double *dc ) {
+  double a[3];   /* The E-terms */
+  double v[3];
+  int i;
+
+  /* Note the preference for IAU routines */
+
+  /* Retrieve the E-terms */
+  palEtrms( eq, a );
+
+  /* Spherical to Cartesian */
+  eraS2c( rm, dm, v );
+
+  /* Include the E-terms */
+  for (i=0; i<3; i++) {
+    v[i] += a[i];
+  }
+
+  /* Cartesian to spherical */
+  eraC2s( v, rc, dc );
+
+  /* Bring RA into conventional range */
+  *rc = eraAnp( *rc );
+
+}