File Coverage

erfasrc/src/gst00a.c
Criterion Covered Total %
statement 0 5 0.0
branch n/a
condition n/a
subroutine n/a
pod n/a
total 0 5 0.0


line stmt bran cond sub pod time code
1             #include "erfa.h"
2              
3 0           double eraGst00a(double uta, double utb, double tta, double ttb)
4             /*
5             ** - - - - - - - - - -
6             ** e r a G s t 0 0 a
7             ** - - - - - - - - - -
8             **
9             ** Greenwich apparent sidereal time (consistent with IAU 2000
10             ** resolutions).
11             **
12             ** Given:
13             ** uta,utb double UT1 as a 2-part Julian Date (Notes 1,2)
14             ** tta,ttb double TT as a 2-part Julian Date (Notes 1,2)
15             **
16             ** Returned (function value):
17             ** double Greenwich apparent sidereal time (radians)
18             **
19             ** Notes:
20             **
21             ** 1) The UT1 and TT dates uta+utb and tta+ttb respectively, are both
22             ** Julian Dates, apportioned in any convenient way between the
23             ** argument pairs. For example, JD=2450123.7 could be expressed in
24             ** any of these ways, among others:
25             **
26             ** Part A Part B
27             **
28             ** 2450123.7 0.0 (JD method)
29             ** 2451545.0 -1421.3 (J2000 method)
30             ** 2400000.5 50123.2 (MJD method)
31             ** 2450123.5 0.2 (date & time method)
32             **
33             ** The JD method is the most natural and convenient to use in
34             ** cases where the loss of several decimal digits of resolution
35             ** is acceptable (in the case of UT; the TT is not at all critical
36             ** in this respect). The J2000 and MJD methods are good compromises
37             ** between resolution and convenience. For UT, the date & time
38             ** method is best matched to the algorithm that is used by the Earth
39             ** Rotation Angle function, called internally: maximum precision is
40             ** delivered when the uta argument is for 0hrs UT1 on the day in
41             ** question and the utb argument lies in the range 0 to 1, or vice
42             ** versa.
43             **
44             ** 2) Both UT1 and TT are required, UT1 to predict the Earth rotation
45             ** and TT to predict the effects of precession-nutation. If UT1 is
46             ** used for both purposes, errors of order 100 microarcseconds
47             ** result.
48             **
49             ** 3) This GAST is compatible with the IAU 2000 resolutions and must be
50             ** used only in conjunction with other IAU 2000 compatible
51             ** components such as precession-nutation.
52             **
53             ** 4) The result is returned in the range 0 to 2pi.
54             **
55             ** 5) The algorithm is from Capitaine et al. (2003) and IERS
56             ** Conventions 2003.
57             **
58             ** Called:
59             ** eraGmst00 Greenwich mean sidereal time, IAU 2000
60             ** eraEe00a equation of the equinoxes, IAU 2000A
61             ** eraAnp normalize angle into range 0 to 2pi
62             **
63             ** References:
64             **
65             ** Capitaine, N., Wallace, P.T. and McCarthy, D.D., "Expressions to
66             ** implement the IAU 2000 definition of UT1", Astronomy &
67             ** Astrophysics, 406, 1135-1149 (2003)
68             **
69             ** McCarthy, D. D., Petit, G. (eds.), IERS Conventions (2003),
70             ** IERS Technical Note No. 32, BKG (2004)
71             **
72             ** Copyright (C) 2013-2019, NumFOCUS Foundation.
73             ** Derived, with permission, from the SOFA library. See notes at end of file.
74             */
75             {
76             double gmst00, ee00a, gst;
77              
78              
79 0           gmst00 = eraGmst00(uta, utb, tta, ttb);
80 0           ee00a = eraEe00a(tta, ttb);
81 0           gst = eraAnp(gmst00 + ee00a);
82              
83 0           return gst;
84              
85             }
86             /*----------------------------------------------------------------------
87             **
88             **
89             ** Copyright (C) 2013-2019, NumFOCUS Foundation.
90             ** All rights reserved.
91             **
92             ** This library is derived, with permission, from the International
93             ** Astronomical Union's "Standards of Fundamental Astronomy" library,
94             ** available from http://www.iausofa.org.
95             **
96             ** The ERFA version is intended to retain identical functionality to
97             ** the SOFA library, but made distinct through different function and
98             ** file names, as set out in the SOFA license conditions. The SOFA
99             ** original has a role as a reference standard for the IAU and IERS,
100             ** and consequently redistribution is permitted only in its unaltered
101             ** state. The ERFA version is not subject to this restriction and
102             ** therefore can be included in distributions which do not support the
103             ** concept of "read only" software.
104             **
105             ** Although the intent is to replicate the SOFA API (other than
106             ** replacement of prefix names) and results (with the exception of
107             ** bugs; any that are discovered will be fixed), SOFA is not
108             ** responsible for any errors found in this version of the library.
109             **
110             ** If you wish to acknowledge the SOFA heritage, please acknowledge
111             ** that you are using a library derived from SOFA, rather than SOFA
112             ** itself.
113             **
114             **
115             ** TERMS AND CONDITIONS
116             **
117             ** Redistribution and use in source and binary forms, with or without
118             ** modification, are permitted provided that the following conditions
119             ** are met:
120             **
121             ** 1 Redistributions of source code must retain the above copyright
122             ** notice, this list of conditions and the following disclaimer.
123             **
124             ** 2 Redistributions in binary form must reproduce the above copyright
125             ** notice, this list of conditions and the following disclaimer in
126             ** the documentation and/or other materials provided with the
127             ** distribution.
128             **
129             ** 3 Neither the name of the Standards Of Fundamental Astronomy Board,
130             ** the International Astronomical Union nor the names of its
131             ** contributors may be used to endorse or promote products derived
132             ** from this software without specific prior written permission.
133             **
134             ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
135             ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
136             ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
137             ** FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
138             ** COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
139             ** INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
140             ** BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
141             ** LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
142             ** CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
143             ** LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
144             ** ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
145             ** POSSIBILITY OF SUCH DAMAGE.
146             **
147             */