source: trunk/FACT++/sofa/src/fw2m.c@ 18375

Last change on this file since 18375 was 18346, checked in by tbretz, 11 years ago
File size: 6.6 KB
Line 
1#include "sofa.h"
2
3void iauFw2m(double gamb, double phib, double psi, double eps,
4 double r[3][3])
5/*
6** - - - - - - - -
7** i a u F w 2 m
8** - - - - - - - -
9**
10** Form rotation matrix given the Fukushima-Williams angles.
11**
12** This function is part of the International Astronomical Union's
13** SOFA (Standards Of Fundamental Astronomy) software collection.
14**
15** Status: support function.
16**
17** Given:
18** gamb double F-W angle gamma_bar (radians)
19** phib double F-W angle phi_bar (radians)
20** psi double F-W angle psi (radians)
21** eps double F-W angle epsilon (radians)
22**
23** Returned:
24** r double[3][3] rotation matrix
25**
26** Notes:
27**
28** 1) Naming the following points:
29**
30** e = J2000.0 ecliptic pole,
31** p = GCRS pole,
32** E = ecliptic pole of date,
33** and P = CIP,
34**
35** the four Fukushima-Williams angles are as follows:
36**
37** gamb = gamma = epE
38** phib = phi = pE
39** psi = psi = pEP
40** eps = epsilon = EP
41**
42** 2) The matrix representing the combined effects of frame bias,
43** precession and nutation is:
44**
45** NxPxB = R_1(-eps).R_3(-psi).R_1(phib).R_3(gamb)
46**
47** 3) Three different matrices can be constructed, depending on the
48** supplied angles:
49**
50** o To obtain the nutation x precession x frame bias matrix,
51** generate the four precession angles, generate the nutation
52** components and add them to the psi_bar and epsilon_A angles,
53** and call the present function.
54**
55** o To obtain the precession x frame bias matrix, generate the
56** four precession angles and call the present function.
57**
58** o To obtain the frame bias matrix, generate the four precession
59** angles for date J2000.0 and call the present function.
60**
61** The nutation-only and precession-only matrices can if necessary
62** be obtained by combining these three appropriately.
63**
64** Called:
65** iauIr initialize r-matrix to identity
66** iauRz rotate around Z-axis
67** iauRx rotate around X-axis
68**
69** Reference:
70**
71** Hilton, J. et al., 2006, Celest.Mech.Dyn.Astron. 94, 351
72**
73** This revision: 2013 June 18
74**
75** SOFA release 2015-02-09
76**
77** Copyright (C) 2015 IAU SOFA Board. See notes at end.
78*/
79{
80/* Construct the matrix. */
81 iauIr(r);
82 iauRz(gamb, r);
83 iauRx(phib, r);
84 iauRz(-psi, r);
85 iauRx(-eps, r);
86
87 return;
88
89/*----------------------------------------------------------------------
90**
91** Copyright (C) 2015
92** Standards Of Fundamental Astronomy Board
93** of the International Astronomical Union.
94**
95** =====================
96** SOFA Software License
97** =====================
98**
99** NOTICE TO USER:
100**
101** BY USING THIS SOFTWARE YOU ACCEPT THE FOLLOWING SIX TERMS AND
102** CONDITIONS WHICH APPLY TO ITS USE.
103**
104** 1. The Software is owned by the IAU SOFA Board ("SOFA").
105**
106** 2. Permission is granted to anyone to use the SOFA software for any
107** purpose, including commercial applications, free of charge and
108** without payment of royalties, subject to the conditions and
109** restrictions listed below.
110**
111** 3. You (the user) may copy and distribute SOFA source code to others,
112** and use and adapt its code and algorithms in your own software,
113** on a world-wide, royalty-free basis. That portion of your
114** distribution that does not consist of intact and unchanged copies
115** of SOFA source code files is a "derived work" that must comply
116** with the following requirements:
117**
118** a) Your work shall be marked or carry a statement that it
119** (i) uses routines and computations derived by you from
120** software provided by SOFA under license to you; and
121** (ii) does not itself constitute software provided by and/or
122** endorsed by SOFA.
123**
124** b) The source code of your derived work must contain descriptions
125** of how the derived work is based upon, contains and/or differs
126** from the original SOFA software.
127**
128** c) The names of all routines in your derived work shall not
129** include the prefix "iau" or "sofa" or trivial modifications
130** thereof such as changes of case.
131**
132** d) The origin of the SOFA components of your derived work must
133** not be misrepresented; you must not claim that you wrote the
134** original software, nor file a patent application for SOFA
135** software or algorithms embedded in the SOFA software.
136**
137** e) These requirements must be reproduced intact in any source
138** distribution and shall apply to anyone to whom you have
139** granted a further right to modify the source code of your
140** derived work.
141**
142** Note that, as originally distributed, the SOFA software is
143** intended to be a definitive implementation of the IAU standards,
144** and consequently third-party modifications are discouraged. All
145** variations, no matter how minor, must be explicitly marked as
146** such, as explained above.
147**
148** 4. You shall not cause the SOFA software to be brought into
149** disrepute, either by misuse, or use for inappropriate tasks, or
150** by inappropriate modification.
151**
152** 5. The SOFA software is provided "as is" and SOFA makes no warranty
153** as to its use or performance. SOFA does not and cannot warrant
154** the performance or results which the user may obtain by using the
155** SOFA software. SOFA makes no warranties, express or implied, as
156** to non-infringement of third party rights, merchantability, or
157** fitness for any particular purpose. In no event will SOFA be
158** liable to the user for any consequential, incidental, or special
159** damages, including any lost profits or lost savings, even if a
160** SOFA representative has been advised of such damages, or for any
161** claim by any third party.
162**
163** 6. The provision of any version of the SOFA software under the terms
164** and conditions specified herein does not imply that future
165** versions will also be made available under the same terms and
166** conditions.
167*
168** In any published work or commercial product which uses the SOFA
169** software directly, acknowledgement (see www.iausofa.org) is
170** appreciated.
171**
172** Correspondence concerning SOFA software should be addressed as
173** follows:
174**
175** By email: sofa@ukho.gov.uk
176** By post: IAU SOFA Center
177** HM Nautical Almanac Office
178** UK Hydrographic Office
179** Admiralty Way, Taunton
180** Somerset, TA1 2DN
181** United Kingdom
182**
183**--------------------------------------------------------------------*/
184}
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