1 /*
2 *+
3 * Name:
4 * palPm
5
6 * Purpose:
7 * Apply corrections for proper motion a star RA,Dec
8
9 * Language:
10 * Starlink ANSI C
11
12 * Type of Module:
13 * Library routine
14
15 * Invocation:
16 * void palPm ( double r0, double d0, double pr, double pd,
17 * double px, double rv, double ep0, double ep1,
18 * double *r1, double *d1 );
19
20 * Arguments:
21 * r0 = double (Given)
22 * RA at epoch ep0 (radians)
23 * d0 = double (Given)
24 * Dec at epoch ep0 (radians)
25 * pr = double (Given)
26 * RA proper motion in radians per year.
27 * pd = double (Given)
28 * Dec proper motion in radians per year.
29 * px = double (Given)
30 * Parallax (arcsec)
31 * rv = double (Given)
32 * Radial velocity (km/sec +ve if receding)
33 * ep0 = double (Given)
34 * Start epoch in years, assumed to be Julian.
35 * ep1 = double (Given)
36 * End epoch in years, assumed to be Julian.
37 * r1 = double * (Returned)
38 * RA at epoch ep1 (radians)
39 * d1 = double * (Returned)
40 * Dec at epoch ep1 (radians)
41
42 * Description:
43 * Apply corrections for proper motion to a star RA,Dec using the
44 * SOFA/ERFA routine eraStarpm.
45
46 * Authors:
47 * TIMJ: Tim Jenness (JAC, Hawaii)
48 * {enter_new_authors_here}
49
50 * Notes:
51 * - Uses eraStarpm but ignores the status returns from that routine.
52 * In particular note that parallax should not be zero when the
53 * proper motions are non-zero. SLA/F allows parallax to be zero.
54 * - Assumes all epochs are Julian epochs.
55
56 * History:
57 * 2012-03-02 (TIMJ):
58 * Initial version
59 * Adapted with permission from the Fortran SLALIB library.
60 * {enter_further_changes_here}
61
62 * Copyright:
63 * Copyright (C) 2012 Science and Technology Facilities Council.
64 * All Rights Reserved.
65
66 * Licence:
67 * This program is free software; you can redistribute it and/or
68 * modify it under the terms of the GNU General Public License as
69 * published by the Free Software Foundation; either version 3 of
70 * the License, or (at your option) any later version.
71 *
72 * This program is distributed in the hope that it will be
73 * useful, but WITHOUT ANY WARRANTY; without even the implied
74 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
75 * PURPOSE. See the GNU General Public License for more details.
76 *
77 * You should have received a copy of the GNU General Public License
78 * along with this program; if not, write to the Free Software
79 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
80 * MA 02110-1301, USA.
81
82 * Bugs:
83 * {note_any_bugs_here}
84 *-
85 */
86
87 #include "pal.h"
88 #include "pal1sofa.h"
89
palPm(double r0,double d0,double pr,double pd,double px,double rv,double ep0,double ep1,double * r1,double * d1)90 void palPm ( double r0, double d0, double pr, double pd,
91 double px, double rv, double ep0, double ep1,
92 double *r1, double *d1 ) {
93
94 int status;
95 double ep1a, ep1b, ep2a, ep2b;
96 double pmr2, pmd2, px2, rv2;
97
98 /* SOFA/ERFA requires the epochs in TDB MJD so we have to
99 assume that the supplied epochs are Julian years */
100 eraEpj2jd( ep0, &ep1a, &ep1b );
101 eraEpj2jd( ep1, &ep2a, &ep2b );
102
103 status = eraStarpm( r0, d0, pr, pd, px, rv,
104 ep1a, ep1b, ep2a, ep2b,
105 r1, d1,
106 &pmr2, &pmd2, &px2, &rv2 );
107
108 }
109