1 #include "erfa.h"
2
eraAtcc13(double rc,double dc,double pr,double pd,double px,double rv,double date1,double date2,double * ra,double * da)3 void eraAtcc13(double rc, double dc,
4 double pr, double pd, double px, double rv,
5 double date1, double date2,
6 double *ra, double *da)
7 /*
8 ** - - - - - - - - - -
9 ** e r a A t c c 1 3
10 ** - - - - - - - - - -
11 **
12 ** Transform a star's ICRS catalog entry (epoch J2000.0) into ICRS
13 ** astrometric place.
14 **
15 ** Given:
16 ** rc double ICRS right ascension at J2000.0 (radians, Note 1)
17 ** dc double ICRS declination at J2000.0 (radians, Note 1)
18 ** pr double RA proper motion (radians/year, Note 2)
19 ** pd double Dec proper motion (radians/year)
20 ** px double parallax (arcsec)
21 ** rv double radial velocity (km/s, +ve if receding)
22 ** date1 double TDB as a 2-part...
23 ** date2 double ...Julian Date (Note 3)
24 **
25 ** Returned:
26 ** ra,da double* ICRS astrometric RA,Dec (radians)
27 **
28 ** Notes:
29 **
30 ** 1) Star data for an epoch other than J2000.0 (for example from the
31 ** Hipparcos catalog, which has an epoch of J1991.25) will require a
32 ** preliminary call to eraPmsafe before use.
33 **
34 ** 2) The proper motion in RA is dRA/dt rather than cos(Dec)*dRA/dt.
35 **
36 ** 3) The TDB date date1+date2 is a Julian Date, apportioned in any
37 ** convenient way between the two arguments. For example,
38 ** JD(TDB)=2450123.7 could be expressed in any of these ways, among
39 ** others:
40 **
41 ** date1 date2
42 **
43 ** 2450123.7 0.0 (JD method)
44 ** 2451545.0 -1421.3 (J2000 method)
45 ** 2400000.5 50123.2 (MJD method)
46 ** 2450123.5 0.2 (date & time method)
47 **
48 ** The JD method is the most natural and convenient to use in cases
49 ** where the loss of several decimal digits of resolution is
50 ** acceptable. The J2000 method is best matched to the way the
51 ** argument is handled internally and will deliver the optimum
52 ** resolution. The MJD method and the date & time methods are both
53 ** good compromises between resolution and convenience. For most
54 ** applications of this function the choice will not be at all
55 ** critical.
56 **
57 ** TT can be used instead of TDB without any significant impact on
58 ** accuracy.
59 **
60 ** Called:
61 ** eraApci13 astrometry parameters, ICRS-CIRS, 2013
62 ** eraAtccq quick catalog ICRS to astrometric
63 **
64 ** This revision: 2021 April 18
65 **
66 ** Copyright (C) 2013-2021, NumFOCUS Foundation.
67 ** Derived, with permission, from the SOFA library. See notes at end of file.
68 */
69 {
70 /* Star-independent astrometry parameters */
71 eraASTROM astrom;
72
73 double w;
74
75
76 /* The transformation parameters. */
77 eraApci13(date1, date2, &astrom, &w);
78
79 /* Catalog ICRS (epoch J2000.0) to astrometric. */
80 eraAtccq(rc, dc, pr, pd, px, rv, &astrom, ra, da);
81
82 /* Finished. */
83
84 }
85 /*----------------------------------------------------------------------
86 **
87 **
88 ** Copyright (C) 2013-2021, NumFOCUS Foundation.
89 ** All rights reserved.
90 **
91 ** This library is derived, with permission, from the International
92 ** Astronomical Union's "Standards of Fundamental Astronomy" library,
93 ** available from http://www.iausofa.org.
94 **
95 ** The ERFA version is intended to retain identical functionality to
96 ** the SOFA library, but made distinct through different function and
97 ** file names, as set out in the SOFA license conditions. The SOFA
98 ** original has a role as a reference standard for the IAU and IERS,
99 ** and consequently redistribution is permitted only in its unaltered
100 ** state. The ERFA version is not subject to this restriction and
101 ** therefore can be included in distributions which do not support the
102 ** concept of "read only" software.
103 **
104 ** Although the intent is to replicate the SOFA API (other than
105 ** replacement of prefix names) and results (with the exception of
106 ** bugs; any that are discovered will be fixed), SOFA is not
107 ** responsible for any errors found in this version of the library.
108 **
109 ** If you wish to acknowledge the SOFA heritage, please acknowledge
110 ** that you are using a library derived from SOFA, rather than SOFA
111 ** itself.
112 **
113 **
114 ** TERMS AND CONDITIONS
115 **
116 ** Redistribution and use in source and binary forms, with or without
117 ** modification, are permitted provided that the following conditions
118 ** are met:
119 **
120 ** 1 Redistributions of source code must retain the above copyright
121 ** notice, this list of conditions and the following disclaimer.
122 **
123 ** 2 Redistributions in binary form must reproduce the above copyright
124 ** notice, this list of conditions and the following disclaimer in
125 ** the documentation and/or other materials provided with the
126 ** distribution.
127 **
128 ** 3 Neither the name of the Standards Of Fundamental Astronomy Board,
129 ** the International Astronomical Union nor the names of its
130 ** contributors may be used to endorse or promote products derived
131 ** from this software without specific prior written permission.
132 **
133 ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
134 ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
135 ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
136 ** FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
137 ** COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
138 ** INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
139 ** BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
140 ** LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
141 ** CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
142 ** LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
143 ** ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
144 ** POSSIBILITY OF SUCH DAMAGE.
145 **
146 */
147