FACT++  1.0
aper13.c
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1 #include "erfa.h"
2 
3 void eraAper13(double ut11, double ut12, eraASTROM *astrom)
4 /*
5 ** - - - - - - - - - -
6 ** e r a A p e r 1 3
7 ** - - - - - - - - - -
8 **
9 ** In the star-independent astrometry parameters, update only the
10 ** Earth rotation angle. The caller provides UT1, (n.b. not UTC).
11 **
12 ** Given:
13 ** ut11 double UT1 as a 2-part...
14 ** ut12 double ...Julian Date (Note 1)
15 ** astrom eraASTROM* star-independent astrometry parameters:
16 ** pmt double not used
17 ** eb double[3] not used
18 ** eh double[3] not used
19 ** em double not used
20 ** v double[3] not used
21 ** bm1 double not used
22 ** bpn double[3][3] not used
23 ** along double longitude + s' (radians)
24 ** xpl double not used
25 ** ypl double not used
26 ** sphi double not used
27 ** cphi double not used
28 ** diurab double not used
29 ** eral double not used
30 ** refa double not used
31 ** refb double not used
32 **
33 ** Returned:
34 ** astrom eraASTROM* star-independent astrometry parameters:
35 ** pmt double unchanged
36 ** eb double[3] unchanged
37 ** eh double[3] unchanged
38 ** em double unchanged
39 ** v double[3] unchanged
40 ** bm1 double unchanged
41 ** bpn double[3][3] unchanged
42 ** along double unchanged
43 ** xpl double unchanged
44 ** ypl double unchanged
45 ** sphi double unchanged
46 ** cphi double unchanged
47 ** diurab double unchanged
48 ** eral double "local" Earth rotation angle (radians)
49 ** refa double unchanged
50 ** refb double unchanged
51 **
52 ** Notes:
53 **
54 ** 1) The UT1 date (n.b. not UTC) ut11+ut12 is a Julian Date,
55 ** apportioned in any convenient way between the arguments ut11 and
56 ** ut12. For example, JD(UT1)=2450123.7 could be expressed in any
57 ** of these ways, among others:
58 **
59 ** ut11 ut12
60 **
61 ** 2450123.7 0.0 (JD method)
62 ** 2451545.0 -1421.3 (J2000 method)
63 ** 2400000.5 50123.2 (MJD method)
64 ** 2450123.5 0.2 (date & time method)
65 **
66 ** The JD method is the most natural and convenient to use in cases
67 ** where the loss of several decimal digits of resolution is
68 ** acceptable. The J2000 and MJD methods are good compromises
69 ** between resolution and convenience. The date & time method is
70 ** best matched to the algorithm used: maximum precision is
71 ** delivered when the ut11 argument is for 0hrs UT1 on the day in
72 ** question and the ut12 argument lies in the range 0 to 1, or vice
73 ** versa.
74 **
75 ** 2) If the caller wishes to provide the Earth rotation angle itself,
76 ** the function eraAper can be used instead. One use of this
77 ** technique is to substitute Greenwich apparent sidereal time and
78 ** thereby to support equinox based transformations directly.
79 **
80 ** 3) This is one of several functions that inserts into the astrom
81 ** structure star-independent parameters needed for the chain of
82 ** astrometric transformations ICRS <-> GCRS <-> CIRS <-> observed.
83 **
84 ** The various functions support different classes of observer and
85 ** portions of the transformation chain:
86 **
87 ** functions observer transformation
88 **
89 ** eraApcg eraApcg13 geocentric ICRS <-> GCRS
90 ** eraApci eraApci13 terrestrial ICRS <-> CIRS
91 ** eraApco eraApco13 terrestrial ICRS <-> observed
92 ** eraApcs eraApcs13 space ICRS <-> GCRS
93 ** eraAper eraAper13 terrestrial update Earth rotation
94 ** eraApio eraApio13 terrestrial CIRS <-> observed
95 **
96 ** Those with names ending in "13" use contemporary ERFA models to
97 ** compute the various ephemerides. The others accept ephemerides
98 ** supplied by the caller.
99 **
100 ** The transformation from ICRS to GCRS covers space motion,
101 ** parallax, light deflection, and aberration. From GCRS to CIRS
102 ** comprises frame bias and precession-nutation. From CIRS to
103 ** observed takes account of Earth rotation, polar motion, diurnal
104 ** aberration and parallax (unless subsumed into the ICRS <-> GCRS
105 ** transformation), and atmospheric refraction.
106 **
107 ** Called:
108 ** eraAper astrometry parameters: update ERA
109 ** eraEra00 Earth rotation angle, IAU 2000
110 **
111 ** Copyright (C) 2013-2015, NumFOCUS Foundation.
112 ** Derived, with permission, from the SOFA library. See notes at end of file.
113 */
114 {
115  eraAper(eraEra00(ut11,ut12), astrom);
116 
117 /* Finished. */
118 
119 }
120 /*----------------------------------------------------------------------
121 **
122 **
123 ** Copyright (C) 2013-2015, NumFOCUS Foundation.
124 ** All rights reserved.
125 **
126 ** This library is derived, with permission, from the International
127 ** Astronomical Union's "Standards of Fundamental Astronomy" library,
128 ** available from http://www.iausofa.org.
129 **
130 ** The ERFA version is intended to retain identical functionality to
131 ** the SOFA library, but made distinct through different function and
132 ** file names, as set out in the SOFA license conditions. The SOFA
133 ** original has a role as a reference standard for the IAU and IERS,
134 ** and consequently redistribution is permitted only in its unaltered
135 ** state. The ERFA version is not subject to this restriction and
136 ** therefore can be included in distributions which do not support the
137 ** concept of "read only" software.
138 **
139 ** Although the intent is to replicate the SOFA API (other than
140 ** replacement of prefix names) and results (with the exception of
141 ** bugs; any that are discovered will be fixed), SOFA is not
142 ** responsible for any errors found in this version of the library.
143 **
144 ** If you wish to acknowledge the SOFA heritage, please acknowledge
145 ** that you are using a library derived from SOFA, rather than SOFA
146 ** itself.
147 **
148 **
149 ** TERMS AND CONDITIONS
150 **
151 ** Redistribution and use in source and binary forms, with or without
152 ** modification, are permitted provided that the following conditions
153 ** are met:
154 **
155 ** 1 Redistributions of source code must retain the above copyright
156 ** notice, this list of conditions and the following disclaimer.
157 **
158 ** 2 Redistributions in binary form must reproduce the above copyright
159 ** notice, this list of conditions and the following disclaimer in
160 ** the documentation and/or other materials provided with the
161 ** distribution.
162 **
163 ** 3 Neither the name of the Standards Of Fundamental Astronomy Board,
164 ** the International Astronomical Union nor the names of its
165 ** contributors may be used to endorse or promote products derived
166 ** from this software without specific prior written permission.
167 **
168 ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
169 ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
170 ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
171 ** FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
172 ** COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
173 ** INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
174 ** BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
175 ** LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
176 ** CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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179 ** POSSIBILITY OF SUCH DAMAGE.
180 **
181 */
eraAper13
void eraAper13(double ut11, double ut12, eraASTROM *astrom)
Definition: aper13.c:3
eraAper
void eraAper(double theta, eraASTROM *astrom)
Definition: aper.c:3
eraEra00
double eraEra00(double dj1, double dj2)
Definition: era00.c:3