source: trunk/FACT++/erfa/src/pnm06a.c@ 18350

Last change on this file since 18350 was 18348, checked in by tbretz, 9 years ago
File size: 5.2 KB
Line 
1#include "erfa.h"
2
3void eraPnm06a(double date1, double date2, double rnpb[3][3])
4/*
5** - - - - - - - - - -
6** e r a P n m 0 6 a
7** - - - - - - - - - -
8**
9** Form the matrix of precession-nutation for a given date (including
10** frame bias), IAU 2006 precession and IAU 2000A nutation models.
11**
12** Given:
13** date1,date2 double TT as a 2-part Julian Date (Note 1)
14**
15** Returned:
16** rnpb double[3][3] bias-precession-nutation matrix (Note 2)
17**
18** Notes:
19**
20** 1) The TT date date1+date2 is a Julian Date, apportioned in any
21** convenient way between the two arguments. For example,
22** JD(TT)=2450123.7 could be expressed in any of these ways,
23** among others:
24**
25** date1 date2
26**
27** 2450123.7 0.0 (JD method)
28** 2451545.0 -1421.3 (J2000 method)
29** 2400000.5 50123.2 (MJD method)
30** 2450123.5 0.2 (date & time method)
31**
32** The JD method is the most natural and convenient to use in
33** cases where the loss of several decimal digits of resolution
34** is acceptable. The J2000 method is best matched to the way
35** the argument is handled internally and will deliver the
36** optimum resolution. The MJD method and the date & time methods
37** are both good compromises between resolution and convenience.
38**
39** 2) The matrix operates in the sense V(date) = rnpb * V(GCRS), where
40** the p-vector V(date) is with respect to the true equatorial triad
41** of date date1+date2 and the p-vector V(GCRS) is with respect to
42** the Geocentric Celestial Reference System (IAU, 2000).
43**
44** Called:
45** eraPfw06 bias-precession F-W angles, IAU 2006
46** eraNut06a nutation, IAU 2006/2000A
47** eraFw2m F-W angles to r-matrix
48**
49** Reference:
50**
51** Capitaine, N. & Wallace, P.T., 2006, Astron.Astrophys. 450, 855.
52**
53** Copyright (C) 2013-2015, NumFOCUS Foundation.
54** Derived, with permission, from the SOFA library. See notes at end of file.
55*/
56{
57 double gamb, phib, psib, epsa, dp, de;
58
59/* Fukushima-Williams angles for frame bias and precession. */
60 eraPfw06(date1, date2, &gamb, &phib, &psib, &epsa);
61
62/* Nutation components. */
63 eraNut06a(date1, date2, &dp, &de);
64
65/* Equinox based nutation x precession x bias matrix. */
66 eraFw2m(gamb, phib, psib + dp, epsa + de, rnpb);
67
68 return;
69
70}
71/*----------------------------------------------------------------------
72**
73**
74** Copyright (C) 2013-2015, NumFOCUS Foundation.
75** All rights reserved.
76**
77** This library is derived, with permission, from the International
78** Astronomical Union's "Standards of Fundamental Astronomy" library,
79** available from http://www.iausofa.org.
80**
81** The ERFA version is intended to retain identical functionality to
82** the SOFA library, but made distinct through different function and
83** file names, as set out in the SOFA license conditions. The SOFA
84** original has a role as a reference standard for the IAU and IERS,
85** and consequently redistribution is permitted only in its unaltered
86** state. The ERFA version is not subject to this restriction and
87** therefore can be included in distributions which do not support the
88** concept of "read only" software.
89**
90** Although the intent is to replicate the SOFA API (other than
91** replacement of prefix names) and results (with the exception of
92** bugs; any that are discovered will be fixed), SOFA is not
93** responsible for any errors found in this version of the library.
94**
95** If you wish to acknowledge the SOFA heritage, please acknowledge
96** that you are using a library derived from SOFA, rather than SOFA
97** itself.
98**
99**
100** TERMS AND CONDITIONS
101**
102** Redistribution and use in source and binary forms, with or without
103** modification, are permitted provided that the following conditions
104** are met:
105**
106** 1 Redistributions of source code must retain the above copyright
107** notice, this list of conditions and the following disclaimer.
108**
109** 2 Redistributions in binary form must reproduce the above copyright
110** notice, this list of conditions and the following disclaimer in
111** the documentation and/or other materials provided with the
112** distribution.
113**
114** 3 Neither the name of the Standards Of Fundamental Astronomy Board,
115** the International Astronomical Union nor the names of its
116** contributors may be used to endorse or promote products derived
117** from this software without specific prior written permission.
118**
119** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
120** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
121** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
122** FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
123** COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
124** INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
125** BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
126** LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
127** CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
128** LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
129** ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
130** POSSIBILITY OF SUCH DAMAGE.
131**
132*/
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