source: branches/FACT++_part_filenames/erfa/src/pn00.c@ 18732

Last change on this file since 18732 was 18711, checked in by tbretz, 8 years ago
Updated to ERFA 1.3.0 (no relevant code change except the leap second at the beginning of 2017)
File size: 7.5 KB
Line 
1#include "erfa.h"
2
3void eraPn00(double date1, double date2, double dpsi, double deps,
4 double *epsa,
5 double rb[3][3], double rp[3][3], double rbp[3][3],
6 double rn[3][3], double rbpn[3][3])
7/*
8** - - - - - - - -
9** e r a P n 0 0
10** - - - - - - - -
11**
12** Precession-nutation, IAU 2000 model: a multi-purpose function,
13** supporting classical (equinox-based) use directly and CIO-based
14** use indirectly.
15**
16** Given:
17** date1,date2 double TT as a 2-part Julian Date (Note 1)
18** dpsi,deps double nutation (Note 2)
19**
20** Returned:
21** epsa double mean obliquity (Note 3)
22** rb double[3][3] frame bias matrix (Note 4)
23** rp double[3][3] precession matrix (Note 5)
24** rbp double[3][3] bias-precession matrix (Note 6)
25** rn double[3][3] nutation matrix (Note 7)
26** rbpn double[3][3] GCRS-to-true matrix (Note 8)
27**
28** Notes:
29**
30** 1) The TT date date1+date2 is a Julian Date, apportioned in any
31** convenient way between the two arguments. For example,
32** JD(TT)=2450123.7 could be expressed in any of these ways,
33** among others:
34**
35** date1 date2
36**
37** 2450123.7 0.0 (JD method)
38** 2451545.0 -1421.3 (J2000 method)
39** 2400000.5 50123.2 (MJD method)
40** 2450123.5 0.2 (date & time method)
41**
42** The JD method is the most natural and convenient to use in
43** cases where the loss of several decimal digits of resolution
44** is acceptable. The J2000 method is best matched to the way
45** the argument is handled internally and will deliver the
46** optimum resolution. The MJD method and the date & time methods
47** are both good compromises between resolution and convenience.
48**
49** 2) The caller is responsible for providing the nutation components;
50** they are in longitude and obliquity, in radians and are with
51** respect to the equinox and ecliptic of date. For high-accuracy
52** applications, free core nutation should be included as well as
53** any other relevant corrections to the position of the CIP.
54**
55** 3) The returned mean obliquity is consistent with the IAU 2000
56** precession-nutation models.
57**
58** 4) The matrix rb transforms vectors from GCRS to J2000.0 mean
59** equator and equinox by applying frame bias.
60**
61** 5) The matrix rp transforms vectors from J2000.0 mean equator and
62** equinox to mean equator and equinox of date by applying
63** precession.
64**
65** 6) The matrix rbp transforms vectors from GCRS to mean equator and
66** equinox of date by applying frame bias then precession. It is
67** the product rp x rb.
68**
69** 7) The matrix rn transforms vectors from mean equator and equinox of
70** date to true equator and equinox of date by applying the nutation
71** (luni-solar + planetary).
72**
73** 8) The matrix rbpn transforms vectors from GCRS to true equator and
74** equinox of date. It is the product rn x rbp, applying frame
75** bias, precession and nutation in that order.
76**
77** 9) It is permissible to re-use the same array in the returned
78** arguments. The arrays are filled in the order given.
79**
80** Called:
81** eraPr00 IAU 2000 precession adjustments
82** eraObl80 mean obliquity, IAU 1980
83** eraBp00 frame bias and precession matrices, IAU 2000
84** eraCr copy r-matrix
85** eraNumat form nutation matrix
86** eraRxr product of two r-matrices
87**
88** Reference:
89**
90** Capitaine, N., Chapront, J., Lambert, S. and Wallace, P.,
91** "Expressions for the Celestial Intermediate Pole and Celestial
92** Ephemeris Origin consistent with the IAU 2000A precession-
93** nutation model", Astron.Astrophys. 400, 1145-1154 (2003)
94**
95** n.b. The celestial ephemeris origin (CEO) was renamed "celestial
96** intermediate origin" (CIO) by IAU 2006 Resolution 2.
97**
98** Copyright (C) 2013-2016, NumFOCUS Foundation.
99** Derived, with permission, from the SOFA library. See notes at end of file.
100*/
101{
102 double dpsipr, depspr, rbpw[3][3], rnw[3][3];
103
104
105/* IAU 2000 precession-rate adjustments. */
106 eraPr00(date1, date2, &dpsipr, &depspr);
107
108/* Mean obliquity, consistent with IAU 2000 precession-nutation. */
109 *epsa = eraObl80(date1, date2) + depspr;
110
111/* Frame bias and precession matrices and their product. */
112 eraBp00(date1, date2, rb, rp, rbpw);
113 eraCr(rbpw, rbp);
114
115/* Nutation matrix. */
116 eraNumat(*epsa, dpsi, deps, rnw);
117 eraCr(rnw, rn);
118
119/* Bias-precession-nutation matrix (classical). */
120 eraRxr(rnw, rbpw, rbpn);
121
122 return;
123
124}
125/*----------------------------------------------------------------------
126**
127**
128** Copyright (C) 2013-2016, NumFOCUS Foundation.
129** All rights reserved.
130**
131** This library is derived, with permission, from the International
132** Astronomical Union's "Standards of Fundamental Astronomy" library,
133** available from http://www.iausofa.org.
134**
135** The ERFA version is intended to retain identical functionality to
136** the SOFA library, but made distinct through different function and
137** file names, as set out in the SOFA license conditions. The SOFA
138** original has a role as a reference standard for the IAU and IERS,
139** and consequently redistribution is permitted only in its unaltered
140** state. The ERFA version is not subject to this restriction and
141** therefore can be included in distributions which do not support the
142** concept of "read only" software.
143**
144** Although the intent is to replicate the SOFA API (other than
145** replacement of prefix names) and results (with the exception of
146** bugs; any that are discovered will be fixed), SOFA is not
147** responsible for any errors found in this version of the library.
148**
149** If you wish to acknowledge the SOFA heritage, please acknowledge
150** that you are using a library derived from SOFA, rather than SOFA
151** itself.
152**
153**
154** TERMS AND CONDITIONS
155**
156** Redistribution and use in source and binary forms, with or without
157** modification, are permitted provided that the following conditions
158** are met:
159**
160** 1 Redistributions of source code must retain the above copyright
161** notice, this list of conditions and the following disclaimer.
162**
163** 2 Redistributions in binary form must reproduce the above copyright
164** notice, this list of conditions and the following disclaimer in
165** the documentation and/or other materials provided with the
166** distribution.
167**
168** 3 Neither the name of the Standards Of Fundamental Astronomy Board,
169** the International Astronomical Union nor the names of its
170** contributors may be used to endorse or promote products derived
171** from this software without specific prior written permission.
172**
173** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
174** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
175** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
176** FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
177** COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
178** INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
179** BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
180** LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
181** CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
182** LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
183** ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
184** POSSIBILITY OF SUCH DAMAGE.
185**
186*/
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