source: branches/FACT++_lidctrl_usb/erfa/src/c2tcio.c@ 19875

Last change on this file since 19875 was 18711, checked in by tbretz, 10 years ago
Updated to ERFA 1.3.0 (no relevant code change except the leap second at the beginning of 2017)
File size: 5.1 KB
Line 
1#include "erfa.h"
2
3void eraC2tcio(double rc2i[3][3], double era, double rpom[3][3],
4 double rc2t[3][3])
5/*
6** - - - - - - - - - -
7** e r a C 2 t c i o
8** - - - - - - - - - -
9**
10** Assemble the celestial to terrestrial matrix from CIO-based
11** components (the celestial-to-intermediate matrix, the Earth Rotation
12** Angle and the polar motion matrix).
13**
14** Given:
15** rc2i double[3][3] celestial-to-intermediate matrix
16** era double Earth rotation angle (radians)
17** rpom double[3][3] polar-motion matrix
18**
19** Returned:
20** rc2t double[3][3] celestial-to-terrestrial matrix
21**
22** Notes:
23**
24** 1) This function constructs the rotation matrix that transforms
25** vectors in the celestial system into vectors in the terrestrial
26** system. It does so starting from precomputed components, namely
27** the matrix which rotates from celestial coordinates to the
28** intermediate frame, the Earth rotation angle and the polar motion
29** matrix. One use of the present function is when generating a
30** series of celestial-to-terrestrial matrices where only the Earth
31** Rotation Angle changes, avoiding the considerable overhead of
32** recomputing the precession-nutation more often than necessary to
33** achieve given accuracy objectives.
34**
35** 2) The relationship between the arguments is as follows:
36**
37** [TRS] = RPOM * R_3(ERA) * rc2i * [CRS]
38**
39** = rc2t * [CRS]
40**
41** where [CRS] is a vector in the Geocentric Celestial Reference
42** System and [TRS] is a vector in the International Terrestrial
43** Reference System (see IERS Conventions 2003).
44**
45** Called:
46** eraCr copy r-matrix
47** eraRz rotate around Z-axis
48** eraRxr product of two r-matrices
49**
50** Reference:
51**
52** McCarthy, D. D., Petit, G. (eds.), 2004, IERS Conventions (2003),
53** IERS Technical Note No. 32, BKG
54**
55** Copyright (C) 2013-2016, NumFOCUS Foundation.
56** Derived, with permission, from the SOFA library. See notes at end of file.
57*/
58{
59 double r[3][3];
60
61
62/* Construct the matrix. */
63 eraCr(rc2i, r);
64 eraRz(era, r);
65 eraRxr(rpom, r, rc2t);
66
67 return;
68
69}
70/*----------------------------------------------------------------------
71**
72**
73** Copyright (C) 2013-2016, NumFOCUS Foundation.
74** All rights reserved.
75**
76** This library is derived, with permission, from the International
77** Astronomical Union's "Standards of Fundamental Astronomy" library,
78** available from http://www.iausofa.org.
79**
80** The ERFA version is intended to retain identical functionality to
81** the SOFA library, but made distinct through different function and
82** file names, as set out in the SOFA license conditions. The SOFA
83** original has a role as a reference standard for the IAU and IERS,
84** and consequently redistribution is permitted only in its unaltered
85** state. The ERFA version is not subject to this restriction and
86** therefore can be included in distributions which do not support the
87** concept of "read only" software.
88**
89** Although the intent is to replicate the SOFA API (other than
90** replacement of prefix names) and results (with the exception of
91** bugs; any that are discovered will be fixed), SOFA is not
92** responsible for any errors found in this version of the library.
93**
94** If you wish to acknowledge the SOFA heritage, please acknowledge
95** that you are using a library derived from SOFA, rather than SOFA
96** itself.
97**
98**
99** TERMS AND CONDITIONS
100**
101** Redistribution and use in source and binary forms, with or without
102** modification, are permitted provided that the following conditions
103** are met:
104**
105** 1 Redistributions of source code must retain the above copyright
106** notice, this list of conditions and the following disclaimer.
107**
108** 2 Redistributions in binary form must reproduce the above copyright
109** notice, this list of conditions and the following disclaimer in
110** the documentation and/or other materials provided with the
111** distribution.
112**
113** 3 Neither the name of the Standards Of Fundamental Astronomy Board,
114** the International Astronomical Union nor the names of its
115** contributors may be used to endorse or promote products derived
116** from this software without specific prior written permission.
117**
118** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
119** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
120** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
121** FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
122** COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
123** INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
124** BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
125** LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
126** CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
127** LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
128** ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
129** POSSIBILITY OF SUCH DAMAGE.
130**
131*/
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