source: trunk/FACT++/erfa/src/fk5hip.c@ 19126

Last change on this file since 19126 was 18921, checked in by tbretz, 7 years ago
Updated to ERFA 1.4.0
File size: 4.6 KB
Line 
1#include "erfa.h"
2
3void eraFk5hip(double r5h[3][3], double s5h[3])
4/*
5** - - - - - - - - - -
6** e r a F k 5 h i p
7** - - - - - - - - - -
8**
9** FK5 to Hipparcos rotation and spin.
10**
11** Returned:
12** r5h double[3][3] r-matrix: FK5 rotation wrt Hipparcos (Note 2)
13** s5h double[3] r-vector: FK5 spin wrt Hipparcos (Note 3)
14**
15** Notes:
16**
17** 1) This function models the FK5 to Hipparcos transformation as a
18** pure rotation and spin; zonal errors in the FK5 catalogue are
19** not taken into account.
20**
21** 2) The r-matrix r5h operates in the sense:
22**
23** P_Hipparcos = r5h x P_FK5
24**
25** where P_FK5 is a p-vector in the FK5 frame, and P_Hipparcos is
26** the equivalent Hipparcos p-vector.
27**
28** 3) The r-vector s5h represents the time derivative of the FK5 to
29** Hipparcos rotation. The units are radians per year (Julian,
30** TDB).
31**
32** Called:
33** eraRv2m r-vector to r-matrix
34**
35** Reference:
36**
37** F.Mignard & M.Froeschle, Astron. Astrophys. 354, 732-739 (2000).
38**
39** Copyright (C) 2013-2017, NumFOCUS Foundation.
40** Derived, with permission, from the SOFA library. See notes at end of file.
41*/
42{
43 double v[3];
44
45/* FK5 wrt Hipparcos orientation and spin (radians, radians/year) */
46 double epx, epy, epz;
47 double omx, omy, omz;
48
49
50 epx = -19.9e-3 * ERFA_DAS2R;
51 epy = -9.1e-3 * ERFA_DAS2R;
52 epz = 22.9e-3 * ERFA_DAS2R;
53
54 omx = -0.30e-3 * ERFA_DAS2R;
55 omy = 0.60e-3 * ERFA_DAS2R;
56 omz = 0.70e-3 * ERFA_DAS2R;
57
58/* FK5 to Hipparcos orientation expressed as an r-vector. */
59 v[0] = epx;
60 v[1] = epy;
61 v[2] = epz;
62
63/* Re-express as an r-matrix. */
64 eraRv2m(v, r5h);
65
66/* Hipparcos wrt FK5 spin expressed as an r-vector. */
67 s5h[0] = omx;
68 s5h[1] = omy;
69 s5h[2] = omz;
70
71 return;
72
73}
74/*----------------------------------------------------------------------
75**
76**
77** Copyright (C) 2013-2017, NumFOCUS Foundation.
78** All rights reserved.
79**
80** This library is derived, with permission, from the International
81** Astronomical Union's "Standards of Fundamental Astronomy" library,
82** available from http://www.iausofa.org.
83**
84** The ERFA version is intended to retain identical functionality to
85** the SOFA library, but made distinct through different function and
86** file names, as set out in the SOFA license conditions. The SOFA
87** original has a role as a reference standard for the IAU and IERS,
88** and consequently redistribution is permitted only in its unaltered
89** state. The ERFA version is not subject to this restriction and
90** therefore can be included in distributions which do not support the
91** concept of "read only" software.
92**
93** Although the intent is to replicate the SOFA API (other than
94** replacement of prefix names) and results (with the exception of
95** bugs; any that are discovered will be fixed), SOFA is not
96** responsible for any errors found in this version of the library.
97**
98** If you wish to acknowledge the SOFA heritage, please acknowledge
99** that you are using a library derived from SOFA, rather than SOFA
100** itself.
101**
102**
103** TERMS AND CONDITIONS
104**
105** Redistribution and use in source and binary forms, with or without
106** modification, are permitted provided that the following conditions
107** are met:
108**
109** 1 Redistributions of source code must retain the above copyright
110** notice, this list of conditions and the following disclaimer.
111**
112** 2 Redistributions in binary form must reproduce the above copyright
113** notice, this list of conditions and the following disclaimer in
114** the documentation and/or other materials provided with the
115** distribution.
116**
117** 3 Neither the name of the Standards Of Fundamental Astronomy Board,
118** the International Astronomical Union nor the names of its
119** contributors may be used to endorse or promote products derived
120** from this software without specific prior written permission.
121**
122** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
123** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
124** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
125** FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
126** COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
127** INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
128** BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
129** LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
130** CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
131** LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
132** ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
133** POSSIBILITY OF SUCH DAMAGE.
134**
135*/
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