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authorWilliam Joye <wjoye@cfa.harvard.edu>2016-10-17 15:22:52 (GMT)
committerWilliam Joye <wjoye@cfa.harvard.edu>2016-10-17 15:22:52 (GMT)
commit7dd9b970cec6832b8f6118dc2dd91a08d2836648 (patch)
tree4b3c86596ab87f35a3c6213397da07afe1e24d3e /ast/pal/palAddet.c
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parent7fde2daeed593684120d75de07598154f3ddaf2c (diff)
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Merge commit '7fde2daeed593684120d75de07598154f3ddaf2c' as 'ast'
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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 );
+
+}