source: trunk/FACT++/erfa/src/atciq.c@ 19594

Last change on this file since 19594 was 18921, checked in by tbretz, 8 years ago
Updated to ERFA 1.4.0
File size: 6.4 KB
Line 
1#include "erfa.h"
2
3void eraAtciq(double rc, double dc,
4 double pr, double pd, double px, double rv,
5 eraASTROM *astrom, double *ri, double *di)
6/*
7** - - - - - - - - -
8** e r a A t c i q
9** - - - - - - - - -
10**
11** Quick ICRS, epoch J2000.0, to CIRS transformation, given precomputed
12** star-independent astrometry parameters.
13**
14** Use of this function is appropriate when efficiency is important and
15** where many star positions are to be transformed for one date. The
16** star-independent parameters can be obtained by calling one of the
17** functions eraApci[13], eraApcg[13], eraApco[13] or eraApcs[13].
18**
19** If the parallax and proper motions are zero the eraAtciqz function
20** can be used instead.
21**
22** Given:
23** rc,dc double ICRS RA,Dec at J2000.0 (radians)
24** pr double RA proper motion (radians/year; Note 3)
25** pd double Dec proper motion (radians/year)
26** px double parallax (arcsec)
27** rv double radial velocity (km/s, +ve if receding)
28** astrom eraASTROM* star-independent astrometry parameters:
29** pmt double PM time interval (SSB, Julian years)
30** eb double[3] SSB to observer (vector, au)
31** eh double[3] Sun to observer (unit vector)
32** em double distance from Sun to observer (au)
33** v double[3] barycentric observer velocity (vector, c)
34** bm1 double sqrt(1-|v|^2): reciprocal of Lorenz factor
35** bpn double[3][3] bias-precession-nutation matrix
36** along double longitude + s' (radians)
37** xpl double polar motion xp wrt local meridian (radians)
38** ypl double polar motion yp wrt local meridian (radians)
39** sphi double sine of geodetic latitude
40** cphi double cosine of geodetic latitude
41** diurab double magnitude of diurnal aberration vector
42** eral double "local" Earth rotation angle (radians)
43** refa double refraction constant A (radians)
44** refb double refraction constant B (radians)
45**
46** Returned:
47** ri,di double CIRS RA,Dec (radians)
48**
49** Notes:
50**
51** 1) All the vectors are with respect to BCRS axes.
52**
53** 2) Star data for an epoch other than J2000.0 (for example from the
54** Hipparcos catalog, which has an epoch of J1991.25) will require a
55** preliminary call to eraPmsafe before use.
56**
57** 3) The proper motion in RA is dRA/dt rather than cos(Dec)*dRA/dt.
58**
59** Called:
60** eraPmpx proper motion and parallax
61** eraLdsun light deflection by the Sun
62** eraAb stellar aberration
63** eraRxp product of r-matrix and pv-vector
64** eraC2s p-vector to spherical
65** eraAnp normalize angle into range 0 to 2pi
66**
67** Copyright (C) 2013-2017, NumFOCUS Foundation.
68** Derived, with permission, from the SOFA library. See notes at end of file.
69*/
70{
71 double pco[3], pnat[3], ppr[3], pi[3], w;
72
73
74/* Proper motion and parallax, giving BCRS coordinate direction. */
75 eraPmpx(rc, dc, pr, pd, px, rv, astrom->pmt, astrom->eb, pco);
76
77/* Light deflection by the Sun, giving BCRS natural direction. */
78 eraLdsun(pco, astrom->eh, astrom->em, pnat);
79
80/* Aberration, giving GCRS proper direction. */
81 eraAb(pnat, astrom->v, astrom->em, astrom->bm1, ppr);
82
83/* Bias-precession-nutation, giving CIRS proper direction. */
84 eraRxp(astrom->bpn, ppr, pi);
85
86/* CIRS RA,Dec. */
87 eraC2s(pi, &w, di);
88 *ri = eraAnp(w);
89
90/* Finished. */
91
92}
93/*----------------------------------------------------------------------
94**
95**
96** Copyright (C) 2013-2017, NumFOCUS Foundation.
97** All rights reserved.
98**
99** This library is derived, with permission, from the International
100** Astronomical Union's "Standards of Fundamental Astronomy" library,
101** available from http://www.iausofa.org.
102**
103** The ERFA version is intended to retain identical functionality to
104** the SOFA library, but made distinct through different function and
105** file names, as set out in the SOFA license conditions. The SOFA
106** original has a role as a reference standard for the IAU and IERS,
107** and consequently redistribution is permitted only in its unaltered
108** state. The ERFA version is not subject to this restriction and
109** therefore can be included in distributions which do not support the
110** concept of "read only" software.
111**
112** Although the intent is to replicate the SOFA API (other than
113** replacement of prefix names) and results (with the exception of
114** bugs; any that are discovered will be fixed), SOFA is not
115** responsible for any errors found in this version of the library.
116**
117** If you wish to acknowledge the SOFA heritage, please acknowledge
118** that you are using a library derived from SOFA, rather than SOFA
119** itself.
120**
121**
122** TERMS AND CONDITIONS
123**
124** Redistribution and use in source and binary forms, with or without
125** modification, are permitted provided that the following conditions
126** are met:
127**
128** 1 Redistributions of source code must retain the above copyright
129** notice, this list of conditions and the following disclaimer.
130**
131** 2 Redistributions in binary form must reproduce the above copyright
132** notice, this list of conditions and the following disclaimer in
133** the documentation and/or other materials provided with the
134** distribution.
135**
136** 3 Neither the name of the Standards Of Fundamental Astronomy Board,
137** the International Astronomical Union nor the names of its
138** contributors may be used to endorse or promote products derived
139** from this software without specific prior written permission.
140**
141** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
142** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
143** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
144** FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
145** COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
146** INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
147** BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
148** LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
149** CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
150** LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
151** ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
152** POSSIBILITY OF SUCH DAMAGE.
153**
154*/
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