source: trunk/FACT++/pal/palPm.c

Last change on this file was 18347, checked in by tbretz, 9 years ago
File size: 3.2 KB
Line 
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
90void 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}
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