File Coverage

erfasrc/src/c2t00b.c

Criterion	Covered	Total	%
statement	0	6	0.0
branch			n/a
condition			n/a
subroutine			n/a
pod			n/a
total	0	6	0.0

line	stmt	code
1		#include "erfa.h"
2
3	0	void eraC2t00b(double tta, double ttb, double uta, double utb,
4		double xp, double yp, double rc2t[3][3])
5		/*
6		** - - - - - - - - - -
7		** e r a C 2 t 0 0 b
8		** - - - - - - - - - -
9		**
10		** Form the celestial to terrestrial matrix given the date, the UT1 and
11		** the polar motion, using the IAU 2000B nutation model.
12		**
13		** Given:
14		** tta,ttb double TT as a 2-part Julian Date (Note 1)
15		** uta,utb double UT1 as a 2-part Julian Date (Note 1)
16		** xp,yp double coordinates of the pole (radians, Note 2)
17		**
18		** Returned:
19		** rc2t double[3][3] celestial-to-terrestrial matrix (Note 3)
20		**
21		** Notes:
22		**
23		** 1) The TT and UT1 dates tta+ttb and uta+utb are Julian Dates,
24		** apportioned in any convenient way between the arguments uta and
25		** utb. For example, JD(UT1)=2450123.7 could be expressed in any of
26		** these ways, among others:
27		**
28		** uta utb
29		**
30		** 2450123.7 0.0 (JD method)
31		** 2451545.0 -1421.3 (J2000 method)
32		** 2400000.5 50123.2 (MJD method)
33		** 2450123.5 0.2 (date & time method)
34		**
35		** The JD method is the most natural and convenient to use in
36		** cases where the loss of several decimal digits of resolution is
37		** acceptable. The J2000 and MJD methods are good compromises
38		** between resolution and convenience. In the case of uta,utb, the
39		** date & time method is best matched to the Earth rotation angle
40		** algorithm used: maximum precision is delivered when the uta
41		** argument is for 0hrs UT1 on the day in question and the utb
42		** argument lies in the range 0 to 1, or vice versa.
43		**
44		** 2) The arguments xp and yp are the coordinates (in radians) of the
45		** Celestial Intermediate Pole with respect to the International
46		** Terrestrial Reference System (see IERS Conventions 2003),
47		** measured along the meridians to 0 and 90 deg west respectively.
48		**
49		** 3) The matrix rc2t transforms from celestial to terrestrial
50		** coordinates:
51		**
52		** [TRS] = RPOM * R_3(ERA) * RC2I * [CRS]
53		**
54		** = rc2t * [CRS]
55		**
56		** where [CRS] is a vector in the Geocentric Celestial Reference
57		** System and [TRS] is a vector in the International Terrestrial
58		** Reference System (see IERS Conventions 2003), RC2I is the
59		** celestial-to-intermediate matrix, ERA is the Earth rotation
60		** angle and RPOM is the polar motion matrix.
61		**
62		** 4) The present function is faster, but slightly less accurate (about
63		** 1 mas), than the eraC2t00a function.
64		**
65		** Called:
66		** eraC2i00b celestial-to-intermediate matrix, IAU 2000B
67		** eraEra00 Earth rotation angle, IAU 2000
68		** eraPom00 polar motion matrix
69		** eraC2tcio form CIO-based celestial-to-terrestrial matrix
70		**
71		** Reference:
72		**
73		** McCarthy, D. D., Petit, G. (eds.), IERS Conventions (2003),
74		** IERS Technical Note No. 32, BKG (2004)
75		**
76		** Copyright (C) 2013-2020, NumFOCUS Foundation.
77		** Derived, with permission, from the SOFA library. See notes at end of file.
78		*/
79		{
80		double rc2i[3][3], era, rpom[3][3];
81
82
83		/* Form the celestial-to-intermediate matrix for this TT (IAU 2000B). */
84	0	eraC2i00b(tta, ttb, rc2i);
85
86		/* Predict the Earth rotation angle for this UT1. */
87	0	era = eraEra00(uta, utb);
88
89		/* Form the polar motion matrix (neglecting s'). */
90	0	eraPom00(xp, yp, 0.0, rpom);
91
92		/* Combine to form the celestial-to-terrestrial matrix. */
93	0	eraC2tcio(rc2i, era, rpom, rc2t);
94
95	0	return;
96
97		}
98		/*----------------------------------------------------------------------
99		**
100		**
101		** Copyright (C) 2013-2020, NumFOCUS Foundation.
102		** All rights reserved.
103		**
104		** This library is derived, with permission, from the International
105		** Astronomical Union's "Standards of Fundamental Astronomy" library,
106		** available from http://www.iausofa.org.
107		**
108		** The ERFA version is intended to retain identical functionality to
109		** the SOFA library, but made distinct through different function and
110		** file names, as set out in the SOFA license conditions. The SOFA
111		** original has a role as a reference standard for the IAU and IERS,
112		** and consequently redistribution is permitted only in its unaltered
113		** state. The ERFA version is not subject to this restriction and
114		** therefore can be included in distributions which do not support the
115		** concept of "read only" software.
116		**
117		** Although the intent is to replicate the SOFA API (other than
118		** replacement of prefix names) and results (with the exception of
119		** bugs; any that are discovered will be fixed), SOFA is not
120		** responsible for any errors found in this version of the library.
121		**
122		** If you wish to acknowledge the SOFA heritage, please acknowledge
123		** that you are using a library derived from SOFA, rather than SOFA
124		** itself.
125		**
126		**
127		** TERMS AND CONDITIONS
128		**
129		** Redistribution and use in source and binary forms, with or without
130		** modification, are permitted provided that the following conditions
131		** are met:
132		**
133		** 1 Redistributions of source code must retain the above copyright
134		** notice, this list of conditions and the following disclaimer.
135		**
136		** 2 Redistributions in binary form must reproduce the above copyright
137		** notice, this list of conditions and the following disclaimer in
138		** the documentation and/or other materials provided with the
139		** distribution.
140		**
141		** 3 Neither the name of the Standards Of Fundamental Astronomy Board,
142		** the International Astronomical Union nor the names of its
143		** contributors may be used to endorse or promote products derived
144		** from this software without specific prior written permission.
145		**
146		** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
147		** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
148		** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
149		** FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
150		** COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
151		** INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
152		** BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
153		** LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
154		** CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
155		** LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
156		** ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
157		** POSSIBILITY OF SUCH DAMAGE.
158		**
159		*/