source: branches/FACT++_lidctrl_usb/erfa/src/apci.c@ 20021

Last change on this file since 20021 was 18711, checked in by tbretz, 9 years ago
Updated to ERFA 1.3.0 (no relevant code change except the leap second at the beginning of 2017)
File size: 8.0 KB
Line 
1#include "erfa.h"
2
3void eraApci(double date1, double date2,
4 double ebpv[2][3], double ehp[3],
5 double x, double y, double s,
6 eraASTROM *astrom)
7/*
8** - - - - - - - -
9** e r a A p c i
10** - - - - - - - -
11**
12** For a terrestrial observer, prepare star-independent astrometry
13** parameters for transformations between ICRS and geocentric CIRS
14** coordinates. The Earth ephemeris and CIP/CIO are supplied by the
15** caller.
16**
17** The parameters produced by this function are required in the
18** parallax, light deflection, aberration, and bias-precession-nutation
19** parts of the astrometric transformation chain.
20**
21** Given:
22** date1 double TDB as a 2-part...
23** date2 double ...Julian Date (Note 1)
24** ebpv double[2][3] Earth barycentric position/velocity (au, au/day)
25** ehp double[3] Earth heliocentric position (au)
26** x,y double CIP X,Y (components of unit vector)
27** s double the CIO locator s (radians)
28**
29** Returned:
30** astrom eraASTROM* star-independent astrometry parameters:
31** pmt double PM time interval (SSB, Julian years)
32** eb double[3] SSB to observer (vector, au)
33** eh double[3] Sun to observer (unit vector)
34** em double distance from Sun to observer (au)
35** v double[3] barycentric observer velocity (vector, c)
36** bm1 double sqrt(1-|v|^2): reciprocal of Lorenz factor
37** bpn double[3][3] bias-precession-nutation matrix
38** along double unchanged
39** xpl double unchanged
40** ypl double unchanged
41** sphi double unchanged
42** cphi double unchanged
43** diurab double unchanged
44** eral double unchanged
45** refa double unchanged
46** refb double unchanged
47**
48** Notes:
49**
50** 1) The TDB date date1+date2 is a Julian Date, apportioned in any
51** convenient way between the two arguments. For example,
52** JD(TDB)=2450123.7 could be expressed in any of these ways, among
53** others:
54**
55** date1 date2
56**
57** 2450123.7 0.0 (JD method)
58** 2451545.0 -1421.3 (J2000 method)
59** 2400000.5 50123.2 (MJD method)
60** 2450123.5 0.2 (date & time method)
61**
62** The JD method is the most natural and convenient to use in cases
63** where the loss of several decimal digits of resolution is
64** acceptable. The J2000 method is best matched to the way the
65** argument is handled internally and will deliver the optimum
66** resolution. The MJD method and the date & time methods are both
67** good compromises between resolution and convenience. For most
68** applications of this function the choice will not be at all
69** critical.
70**
71** TT can be used instead of TDB without any significant impact on
72** accuracy.
73**
74** 2) All the vectors are with respect to BCRS axes.
75**
76** 3) In cases where the caller does not wish to provide the Earth
77** ephemeris and CIP/CIO, the function eraApci13 can be used instead
78** of the present function. This computes the required quantities
79** using other ERFA functions.
80**
81** 4) This is one of several functions that inserts into the astrom
82** structure star-independent parameters needed for the chain of
83** astrometric transformations ICRS <-> GCRS <-> CIRS <-> observed.
84**
85** The various functions support different classes of observer and
86** portions of the transformation chain:
87**
88** functions observer transformation
89**
90** eraApcg eraApcg13 geocentric ICRS <-> GCRS
91** eraApci eraApci13 terrestrial ICRS <-> CIRS
92** eraApco eraApco13 terrestrial ICRS <-> observed
93** eraApcs eraApcs13 space ICRS <-> GCRS
94** eraAper eraAper13 terrestrial update Earth rotation
95** eraApio eraApio13 terrestrial CIRS <-> observed
96**
97** Those with names ending in "13" use contemporary ERFA models to
98** compute the various ephemerides. The others accept ephemerides
99** supplied by the caller.
100**
101** The transformation from ICRS to GCRS covers space motion,
102** parallax, light deflection, and aberration. From GCRS to CIRS
103** comprises frame bias and precession-nutation. From CIRS to
104** observed takes account of Earth rotation, polar motion, diurnal
105** aberration and parallax (unless subsumed into the ICRS <-> GCRS
106** transformation), and atmospheric refraction.
107**
108** 5) The context structure astrom produced by this function is used by
109** eraAtciq* and eraAticq*.
110**
111** Called:
112** eraApcg astrometry parameters, ICRS-GCRS, geocenter
113** eraC2ixys celestial-to-intermediate matrix, given X,Y and s
114**
115** Copyright (C) 2013-2016, NumFOCUS Foundation.
116** Derived, with permission, from the SOFA library. See notes at end of file.
117*/
118{
119
120/* Star-independent astrometry parameters for geocenter. */
121 eraApcg(date1, date2, ebpv, ehp, astrom);
122
123/* CIO based BPN matrix. */
124 eraC2ixys(x, y, s, astrom->bpn);
125
126/* Finished. */
127
128}
129/*----------------------------------------------------------------------
130**
131**
132** Copyright (C) 2013-2016, NumFOCUS Foundation.
133** All rights reserved.
134**
135** This library is derived, with permission, from the International
136** Astronomical Union's "Standards of Fundamental Astronomy" library,
137** available from http://www.iausofa.org.
138**
139** The ERFA version is intended to retain identical functionality to
140** the SOFA library, but made distinct through different function and
141** file names, as set out in the SOFA license conditions. The SOFA
142** original has a role as a reference standard for the IAU and IERS,
143** and consequently redistribution is permitted only in its unaltered
144** state. The ERFA version is not subject to this restriction and
145** therefore can be included in distributions which do not support the
146** concept of "read only" software.
147**
148** Although the intent is to replicate the SOFA API (other than
149** replacement of prefix names) and results (with the exception of
150** bugs; any that are discovered will be fixed), SOFA is not
151** responsible for any errors found in this version of the library.
152**
153** If you wish to acknowledge the SOFA heritage, please acknowledge
154** that you are using a library derived from SOFA, rather than SOFA
155** itself.
156**
157**
158** TERMS AND CONDITIONS
159**
160** Redistribution and use in source and binary forms, with or without
161** modification, are permitted provided that the following conditions
162** are met:
163**
164** 1 Redistributions of source code must retain the above copyright
165** notice, this list of conditions and the following disclaimer.
166**
167** 2 Redistributions in binary form must reproduce the above copyright
168** notice, this list of conditions and the following disclaimer in
169** the documentation and/or other materials provided with the
170** distribution.
171**
172** 3 Neither the name of the Standards Of Fundamental Astronomy Board,
173** the International Astronomical Union nor the names of its
174** contributors may be used to endorse or promote products derived
175** from this software without specific prior written permission.
176**
177** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
178** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
179** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
180** FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
181** COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
182** INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
183** BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
184** LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
185** CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
186** LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
187** ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
188** POSSIBILITY OF SUCH DAMAGE.
189**
190*/
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