File Coverage

erfasrc/src/atic13.c
Criterion Covered Total %
statement 0 4 0.0
branch n/a
condition n/a
subroutine n/a
pod n/a
total 0 4 0.0


line stmt bran cond sub pod time code
1             #include "erfa.h"
2              
3 0           void eraAtic13(double ri, double di, double date1, double date2,
4             double *rc, double *dc, double *eo)
5             /*
6             ** - - - - - - - - - -
7             ** e r a A t i c 1 3
8             ** - - - - - - - - - -
9             **
10             ** Transform star RA,Dec from geocentric CIRS to ICRS astrometric.
11             **
12             ** Given:
13             ** ri,di double CIRS geocentric RA,Dec (radians)
14             ** date1 double TDB as a 2-part...
15             ** date2 double ...Julian Date (Note 1)
16             **
17             ** Returned:
18             ** rc,dc double ICRS astrometric RA,Dec (radians)
19             ** eo double equation of the origins (ERA-GST, Note 4)
20             **
21             ** Notes:
22             **
23             ** 1) The TDB date date1+date2 is a Julian Date, apportioned in any
24             ** convenient way between the two arguments. For example,
25             ** JD(TDB)=2450123.7 could be expressed in any of these ways, among
26             ** others:
27             **
28             ** date1 date2
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 cases
36             ** where the loss of several decimal digits of resolution is
37             ** acceptable. The J2000 method is best matched to the way the
38             ** argument is handled internally and will deliver the optimum
39             ** resolution. The MJD method and the date & time methods are both
40             ** good compromises between resolution and convenience. For most
41             ** applications of this function the choice will not be at all
42             ** critical.
43             **
44             ** TT can be used instead of TDB without any significant impact on
45             ** accuracy.
46             **
47             ** 2) Iterative techniques are used for the aberration and light
48             ** deflection corrections so that the functions eraAtic13 (or
49             ** eraAticq) and eraAtci13 (or eraAtciq) are accurate inverses;
50             ** even at the edge of the Sun's disk the discrepancy is only about
51             ** 1 nanoarcsecond.
52             **
53             ** 3) The available accuracy is better than 1 milliarcsecond, limited
54             ** mainly by the precession-nutation model that is used, namely
55             ** IAU 2000A/2006. Very close to solar system bodies, additional
56             ** errors of up to several milliarcseconds can occur because of
57             ** unmodeled light deflection; however, the Sun's contribution is
58             ** taken into account, to first order. The accuracy limitations of
59             ** the ERFA function eraEpv00 (used to compute Earth position and
60             ** velocity) can contribute aberration errors of up to
61             ** 5 microarcseconds. Light deflection at the Sun's limb is
62             ** uncertain at the 0.4 mas level.
63             **
64             ** 4) Should the transformation to (equinox based) J2000.0 mean place
65             ** be required rather than (CIO based) ICRS coordinates, subtract the
66             ** equation of the origins from the returned right ascension:
67             ** RA = RI - EO. (The eraAnp function can then be applied, as
68             ** required, to keep the result in the conventional 0-2pi range.)
69             **
70             ** Called:
71             ** eraApci13 astrometry parameters, ICRS-CIRS, 2013
72             ** eraAticq quick CIRS to ICRS astrometric
73             **
74             ** Copyright (C) 2013-2019, NumFOCUS Foundation.
75             ** Derived, with permission, from the SOFA library. See notes at end of file.
76             */
77             {
78             /* Star-independent astrometry parameters */
79             eraASTROM astrom;
80              
81              
82             /* Star-independent astrometry parameters. */
83 0           eraApci13(date1, date2, &astrom, eo);
84              
85             /* CIRS to ICRS astrometric. */
86 0           eraAticq(ri, di, &astrom, rc, dc);
87              
88             /* Finished. */
89              
90 0           }
91             /*----------------------------------------------------------------------
92             **
93             **
94             ** Copyright (C) 2013-2019, NumFOCUS Foundation.
95             ** All rights reserved.
96             **
97             ** This library is derived, with permission, from the International
98             ** Astronomical Union's "Standards of Fundamental Astronomy" library,
99             ** available from http://www.iausofa.org.
100             **
101             ** The ERFA version is intended to retain identical functionality to
102             ** the SOFA library, but made distinct through different function and
103             ** file names, as set out in the SOFA license conditions. The SOFA
104             ** original has a role as a reference standard for the IAU and IERS,
105             ** and consequently redistribution is permitted only in its unaltered
106             ** state. The ERFA version is not subject to this restriction and
107             ** therefore can be included in distributions which do not support the
108             ** concept of "read only" software.
109             **
110             ** Although the intent is to replicate the SOFA API (other than
111             ** replacement of prefix names) and results (with the exception of
112             ** bugs; any that are discovered will be fixed), SOFA is not
113             ** responsible for any errors found in this version of the library.
114             **
115             ** If you wish to acknowledge the SOFA heritage, please acknowledge
116             ** that you are using a library derived from SOFA, rather than SOFA
117             ** itself.
118             **
119             **
120             ** TERMS AND CONDITIONS
121             **
122             ** Redistribution and use in source and binary forms, with or without
123             ** modification, are permitted provided that the following conditions
124             ** are met:
125             **
126             ** 1 Redistributions of source code must retain the above copyright
127             ** notice, this list of conditions and the following disclaimer.
128             **
129             ** 2 Redistributions in binary form must reproduce the above copyright
130             ** notice, this list of conditions and the following disclaimer in
131             ** the documentation and/or other materials provided with the
132             ** distribution.
133             **
134             ** 3 Neither the name of the Standards Of Fundamental Astronomy Board,
135             ** the International Astronomical Union nor the names of its
136             ** contributors may be used to endorse or promote products derived
137             ** from this software without specific prior written permission.
138             **
139             ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
140             ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
141             ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
142             ** FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
143             ** COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
144             ** INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
145             ** BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
146             ** LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
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148             ** LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
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150             ** POSSIBILITY OF SUCH DAMAGE.
151             **
152             */