source: trunk/FACT++/sofa/src/pvtob.c@ 18355

Last change on this file since 18355 was 18346, checked in by tbretz, 11 years ago
File size: 7.5 KB
Line 
1#include "sofa.h"
2
3void iauPvtob(double elong, double phi, double hm,
4 double xp, double yp, double sp, double theta,
5 double pv[2][3])
6/*
7** - - - - - - - - -
8** i a u P v t o b
9** - - - - - - - - -
10**
11** Position and velocity of a terrestrial observing station.
12**
13** This function is part of the International Astronomical Union's
14** SOFA (Standards of Fundamental Astronomy) software collection.
15**
16** Status: support function.
17**
18** Given:
19** elong double longitude (radians, east +ve, Note 1)
20** phi double latitude (geodetic, radians, Note 1)
21** hm double height above ref. ellipsoid (geodetic, m)
22** xp,yp double coordinates of the pole (radians, Note 2)
23** sp double the TIO locator s' (radians, Note 2)
24** theta double Earth rotation angle (radians, Note 3)
25**
26** Returned:
27** pv double[2][3] position/velocity vector (m, m/s, CIRS)
28**
29** Notes:
30**
31** 1) The terrestrial coordinates are with respect to the WGS84
32** reference ellipsoid.
33**
34** 2) xp and yp are the coordinates (in radians) of the Celestial
35** Intermediate Pole with respect to the International Terrestrial
36** Reference System (see IERS Conventions), measured along the
37** meridians 0 and 90 deg west respectively. sp is the TIO locator
38** s', in radians, which positions the Terrestrial Intermediate
39** Origin on the equator. For many applications, xp, yp and
40** (especially) sp can be set to zero.
41**
42** 3) If theta is Greenwich apparent sidereal time instead of Earth
43** rotation angle, the result is with respect to the true equator
44** and equinox of date, i.e. with the x-axis at the equinox rather
45** than the celestial intermediate origin.
46**
47** 4) The velocity units are meters per UT1 second, not per SI second.
48** This is unlikely to have any practical consequences in the modern
49** era.
50**
51** 5) No validation is performed on the arguments. Error cases that
52** could lead to arithmetic exceptions are trapped by the iauGd2gc
53** function, and the result set to zeros.
54**
55** References:
56**
57** McCarthy, D. D., Petit, G. (eds.), IERS Conventions (2003),
58** IERS Technical Note No. 32, BKG (2004)
59**
60** Urban, S. & Seidelmann, P. K. (eds), Explanatory Supplement to
61** the Astronomical Almanac, 3rd ed., University Science Books
62** (2013), Section 7.4.3.3.
63**
64** Called:
65** iauGd2gc geodetic to geocentric transformation
66** iauPom00 polar motion matrix
67** iauTrxp product of transpose of r-matrix and p-vector
68**
69** This revision: 2013 October 9
70**
71** SOFA release 2015-02-09
72**
73** Copyright (C) 2015 IAU SOFA Board. See notes at end.
74*/
75{
76/* Earth rotation rate in radians per UT1 second */
77 const double OM = 1.00273781191135448 * D2PI / DAYSEC;
78
79 double xyzm[3], rpm[3][3], xyz[3], x, y, z, s, c;
80
81/* Geodetic to geocentric transformation (WGS84). */
82 (void) iauGd2gc(1, elong, phi, hm, xyzm);
83
84/* Polar motion and TIO position. */
85 iauPom00(xp, yp, sp, rpm);
86 iauTrxp(rpm, xyzm, xyz);
87 x = xyz[0];
88 y = xyz[1];
89 z = xyz[2];
90
91/* Functions of ERA. */
92 s = sin(theta);
93 c = cos(theta);
94
95/* Position. */
96 pv[0][0] = c*x - s*y;
97 pv[0][1] = s*x + c*y;
98 pv[0][2] = z;
99
100/* Velocity. */
101 pv[1][0] = OM * ( -s*x - c*y );
102 pv[1][1] = OM * ( c*x - s*y );
103 pv[1][2] = 0.0;
104
105/* Finished. */
106
107/*----------------------------------------------------------------------
108**
109** Copyright (C) 2015
110** Standards Of Fundamental Astronomy Board
111** of the International Astronomical Union.
112**
113** =====================
114** SOFA Software License
115** =====================
116**
117** NOTICE TO USER:
118**
119** BY USING THIS SOFTWARE YOU ACCEPT THE FOLLOWING SIX TERMS AND
120** CONDITIONS WHICH APPLY TO ITS USE.
121**
122** 1. The Software is owned by the IAU SOFA Board ("SOFA").
123**
124** 2. Permission is granted to anyone to use the SOFA software for any
125** purpose, including commercial applications, free of charge and
126** without payment of royalties, subject to the conditions and
127** restrictions listed below.
128**
129** 3. You (the user) may copy and distribute SOFA source code to others,
130** and use and adapt its code and algorithms in your own software,
131** on a world-wide, royalty-free basis. That portion of your
132** distribution that does not consist of intact and unchanged copies
133** of SOFA source code files is a "derived work" that must comply
134** with the following requirements:
135**
136** a) Your work shall be marked or carry a statement that it
137** (i) uses routines and computations derived by you from
138** software provided by SOFA under license to you; and
139** (ii) does not itself constitute software provided by and/or
140** endorsed by SOFA.
141**
142** b) The source code of your derived work must contain descriptions
143** of how the derived work is based upon, contains and/or differs
144** from the original SOFA software.
145**
146** c) The names of all routines in your derived work shall not
147** include the prefix "iau" or "sofa" or trivial modifications
148** thereof such as changes of case.
149**
150** d) The origin of the SOFA components of your derived work must
151** not be misrepresented; you must not claim that you wrote the
152** original software, nor file a patent application for SOFA
153** software or algorithms embedded in the SOFA software.
154**
155** e) These requirements must be reproduced intact in any source
156** distribution and shall apply to anyone to whom you have
157** granted a further right to modify the source code of your
158** derived work.
159**
160** Note that, as originally distributed, the SOFA software is
161** intended to be a definitive implementation of the IAU standards,
162** and consequently third-party modifications are discouraged. All
163** variations, no matter how minor, must be explicitly marked as
164** such, as explained above.
165**
166** 4. You shall not cause the SOFA software to be brought into
167** disrepute, either by misuse, or use for inappropriate tasks, or
168** by inappropriate modification.
169**
170** 5. The SOFA software is provided "as is" and SOFA makes no warranty
171** as to its use or performance. SOFA does not and cannot warrant
172** the performance or results which the user may obtain by using the
173** SOFA software. SOFA makes no warranties, express or implied, as
174** to non-infringement of third party rights, merchantability, or
175** fitness for any particular purpose. In no event will SOFA be
176** liable to the user for any consequential, incidental, or special
177** damages, including any lost profits or lost savings, even if a
178** SOFA representative has been advised of such damages, or for any
179** claim by any third party.
180**
181** 6. The provision of any version of the SOFA software under the terms
182** and conditions specified herein does not imply that future
183** versions will also be made available under the same terms and
184** conditions.
185*
186** In any published work or commercial product which uses the SOFA
187** software directly, acknowledgement (see www.iausofa.org) is
188** appreciated.
189**
190** Correspondence concerning SOFA software should be addressed as
191** follows:
192**
193** By email: sofa@ukho.gov.uk
194** By post: IAU SOFA Center
195** HM Nautical Almanac Office
196** UK Hydrographic Office
197** Admiralty Way, Taunton
198** Somerset, TA1 2DN
199** United Kingdom
200**
201**--------------------------------------------------------------------*/
202
203}
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