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Diffstat (limited to 'ast/erfa/s06.c')
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diff --git a/ast/erfa/s06.c b/ast/erfa/s06.c new file mode 100644 index 0000000..21546c5 --- /dev/null +++ b/ast/erfa/s06.c @@ -0,0 +1,377 @@ +#include "erfa.h" + +double eraS06(double date1, double date2, double x, double y) +/* +** - - - - - - - +** e r a S 0 6 +** - - - - - - - +** +** The CIO locator s, positioning the Celestial Intermediate Origin on +** the equator of the Celestial Intermediate Pole, given the CIP's X,Y +** coordinates. Compatible with IAU 2006/2000A precession-nutation. +** +** Given: +** date1,date2 double TT as a 2-part Julian Date (Note 1) +** x,y double CIP coordinates (Note 3) +** +** Returned (function value): +** double the CIO locator s in radians (Note 2) +** +** Notes: +** +** 1) The TT date date1+date2 is a Julian Date, apportioned in any +** convenient way between the two arguments. For example, +** JD(TT)=2450123.7 could be expressed in any of these ways, +** among others: +** +** date1 date2 +** +** 2450123.7 0.0 (JD method) +** 2451545.0 -1421.3 (J2000 method) +** 2400000.5 50123.2 (MJD method) +** 2450123.5 0.2 (date & time method) +** +** The JD method is the most natural and convenient to use in +** cases where the loss of several decimal digits of resolution +** is acceptable. The J2000 method is best matched to the way +** the argument is handled internally and will deliver the +** optimum resolution. The MJD method and the date & time methods +** are both good compromises between resolution and convenience. +** +** 2) The CIO locator s is the difference between the right ascensions +** of the same point in two systems: the two systems are the GCRS +** and the CIP,CIO, and the point is the ascending node of the +** CIP equator. The quantity s remains below 0.1 arcsecond +** throughout 1900-2100. +** +** 3) The series used to compute s is in fact for s+XY/2, where X and Y +** are the x and y components of the CIP unit vector; this series +** is more compact than a direct series for s would be. This +** function requires X,Y to be supplied by the caller, who is +** responsible for providing values that are consistent with the +** supplied date. +** +** 4) The model is consistent with the "P03" precession (Capitaine et +** al. 2003), adopted by IAU 2006 Resolution 1, 2006, and the +** IAU 2000A nutation (with P03 adjustments). +** +** Called: +** eraFal03 mean anomaly of the Moon +** eraFalp03 mean anomaly of the Sun +** eraFaf03 mean argument of the latitude of the Moon +** eraFad03 mean elongation of the Moon from the Sun +** eraFaom03 mean longitude of the Moon's ascending node +** eraFave03 mean longitude of Venus +** eraFae03 mean longitude of Earth +** eraFapa03 general accumulated precession in longitude +** +** References: +** +** Capitaine, N., Wallace, P.T. & Chapront, J., 2003, Astron. +** Astrophys. 432, 355 +** +** McCarthy, D.D., Petit, G. (eds.) 2004, IERS Conventions (2003), +** IERS Technical Note No. 32, BKG +** +** Copyright (C) 2013-2016, NumFOCUS Foundation. +** Derived, with permission, from the SOFA library. See notes at end of file. +*/ +{ +/* Time since J2000.0, in Julian centuries */ + double t; + +/* Miscellaneous */ + int i, j; + double a, w0, w1, w2, w3, w4, w5; + +/* Fundamental arguments */ + double fa[8]; + +/* Returned value */ + double s; + +/* --------------------- */ +/* The series for s+XY/2 */ +/* --------------------- */ + + typedef struct { + int nfa[8]; /* coefficients of l,l',F,D,Om,LVe,LE,pA */ + double s, c; /* sine and cosine coefficients */ + } TERM; + +/* Polynomial coefficients */ + static const double sp[] = { + + /* 1-6 */ + 94.00e-6, + 3808.65e-6, + -122.68e-6, + -72574.11e-6, + 27.98e-6, + 15.62e-6 + }; + +/* Terms of order t^0 */ + static const TERM s0[] = { + + /* 1-10 */ + {{ 0, 0, 0, 0, 1, 0, 0, 0}, -2640.73e-6, 0.39e-6 }, + {{ 0, 0, 0, 0, 2, 0, 0, 0}, -63.53e-6, 0.02e-6 }, + {{ 0, 0, 2, -2, 3, 0, 0, 0}, -11.75e-6, -0.01e-6 }, + {{ 0, 0, 2, -2, 1, 0, 0, 0}, -11.21e-6, -0.01e-6 }, + {{ 0, 0, 2, -2, 2, 0, 0, 0}, 4.57e-6, 0.00e-6 }, + {{ 0, 0, 2, 0, 3, 0, 0, 0}, -2.02e-6, 0.00e-6 }, + {{ 0, 0, 2, 0, 1, 0, 0, 0}, -1.98e-6, 0.00e-6 }, + {{ 0, 0, 0, 0, 3, 0, 0, 0}, 1.72e-6, 0.00e-6 }, + {{ 0, 1, 0, 0, 1, 0, 0, 0}, 1.41e-6, 0.01e-6 }, + {{ 0, 1, 0, 0, -1, 0, 0, 0}, 1.26e-6, 0.01e-6 }, + + /* 11-20 */ + {{ 1, 0, 0, 0, -1, 0, 0, 0}, 0.63e-6, 0.00e-6 }, + {{ 1, 0, 0, 0, 1, 0, 0, 0}, 0.63e-6, 0.00e-6 }, + {{ 0, 1, 2, -2, 3, 0, 0, 0}, -0.46e-6, 0.00e-6 }, + {{ 0, 1, 2, -2, 1, 0, 0, 0}, -0.45e-6, 0.00e-6 }, + {{ 0, 0, 4, -4, 4, 0, 0, 0}, -0.36e-6, 0.00e-6 }, + {{ 0, 0, 1, -1, 1, -8, 12, 0}, 0.24e-6, 0.12e-6 }, + {{ 0, 0, 2, 0, 0, 0, 0, 0}, -0.32e-6, 0.00e-6 }, + {{ 0, 0, 2, 0, 2, 0, 0, 0}, -0.28e-6, 0.00e-6 }, + {{ 1, 0, 2, 0, 3, 0, 0, 0}, -0.27e-6, 0.00e-6 }, + {{ 1, 0, 2, 0, 1, 0, 0, 0}, -0.26e-6, 0.00e-6 }, + + /* 21-30 */ + {{ 0, 0, 2, -2, 0, 0, 0, 0}, 0.21e-6, 0.00e-6 }, + {{ 0, 1, -2, 2, -3, 0, 0, 0}, -0.19e-6, 0.00e-6 }, + {{ 0, 1, -2, 2, -1, 0, 0, 0}, -0.18e-6, 0.00e-6 }, + {{ 0, 0, 0, 0, 0, 8,-13, -1}, 0.10e-6, -0.05e-6 }, + {{ 0, 0, 0, 2, 0, 0, 0, 0}, -0.15e-6, 0.00e-6 }, + {{ 2, 0, -2, 0, -1, 0, 0, 0}, 0.14e-6, 0.00e-6 }, + {{ 0, 1, 2, -2, 2, 0, 0, 0}, 0.14e-6, 0.00e-6 }, + {{ 1, 0, 0, -2, 1, 0, 0, 0}, -0.14e-6, 0.00e-6 }, + {{ 1, 0, 0, -2, -1, 0, 0, 0}, -0.14e-6, 0.00e-6 }, + {{ 0, 0, 4, -2, 4, 0, 0, 0}, -0.13e-6, 0.00e-6 }, + + /* 31-33 */ + {{ 0, 0, 2, -2, 4, 0, 0, 0}, 0.11e-6, 0.00e-6 }, + {{ 1, 0, -2, 0, -3, 0, 0, 0}, -0.11e-6, 0.00e-6 }, + {{ 1, 0, -2, 0, -1, 0, 0, 0}, -0.11e-6, 0.00e-6 } + }; + +/* Terms of order t^1 */ + static const TERM s1[] = { + + /* 1 - 3 */ + {{ 0, 0, 0, 0, 2, 0, 0, 0}, -0.07e-6, 3.57e-6 }, + {{ 0, 0, 0, 0, 1, 0, 0, 0}, 1.73e-6, -0.03e-6 }, + {{ 0, 0, 2, -2, 3, 0, 0, 0}, 0.00e-6, 0.48e-6 } + }; + +/* Terms of order t^2 */ + static const TERM s2[] = { + + /* 1-10 */ + {{ 0, 0, 0, 0, 1, 0, 0, 0}, 743.52e-6, -0.17e-6 }, + {{ 0, 0, 2, -2, 2, 0, 0, 0}, 56.91e-6, 0.06e-6 }, + {{ 0, 0, 2, 0, 2, 0, 0, 0}, 9.84e-6, -0.01e-6 }, + {{ 0, 0, 0, 0, 2, 0, 0, 0}, -8.85e-6, 0.01e-6 }, + {{ 0, 1, 0, 0, 0, 0, 0, 0}, -6.38e-6, -0.05e-6 }, + {{ 1, 0, 0, 0, 0, 0, 0, 0}, -3.07e-6, 0.00e-6 }, + {{ 0, 1, 2, -2, 2, 0, 0, 0}, 2.23e-6, 0.00e-6 }, + {{ 0, 0, 2, 0, 1, 0, 0, 0}, 1.67e-6, 0.00e-6 }, + {{ 1, 0, 2, 0, 2, 0, 0, 0}, 1.30e-6, 0.00e-6 }, + {{ 0, 1, -2, 2, -2, 0, 0, 0}, 0.93e-6, 0.00e-6 }, + + /* 11-20 */ + {{ 1, 0, 0, -2, 0, 0, 0, 0}, 0.68e-6, 0.00e-6 }, + {{ 0, 0, 2, -2, 1, 0, 0, 0}, -0.55e-6, 0.00e-6 }, + {{ 1, 0, -2, 0, -2, 0, 0, 0}, 0.53e-6, 0.00e-6 }, + {{ 0, 0, 0, 2, 0, 0, 0, 0}, -0.27e-6, 0.00e-6 }, + {{ 1, 0, 0, 0, 1, 0, 0, 0}, -0.27e-6, 0.00e-6 }, + {{ 1, 0, -2, -2, -2, 0, 0, 0}, -0.26e-6, 0.00e-6 }, + {{ 1, 0, 0, 0, -1, 0, 0, 0}, -0.25e-6, 0.00e-6 }, + {{ 1, 0, 2, 0, 1, 0, 0, 0}, 0.22e-6, 0.00e-6 }, + {{ 2, 0, 0, -2, 0, 0, 0, 0}, -0.21e-6, 0.00e-6 }, + {{ 2, 0, -2, 0, -1, 0, 0, 0}, 0.20e-6, 0.00e-6 }, + + /* 21-25 */ + {{ 0, 0, 2, 2, 2, 0, 0, 0}, 0.17e-6, 0.00e-6 }, + {{ 2, 0, 2, 0, 2, 0, 0, 0}, 0.13e-6, 0.00e-6 }, + {{ 2, 0, 0, 0, 0, 0, 0, 0}, -0.13e-6, 0.00e-6 }, + {{ 1, 0, 2, -2, 2, 0, 0, 0}, -0.12e-6, 0.00e-6 }, + {{ 0, 0, 2, 0, 0, 0, 0, 0}, -0.11e-6, 0.00e-6 } + }; + +/* Terms of order t^3 */ + static const TERM s3[] = { + + /* 1-4 */ + {{ 0, 0, 0, 0, 1, 0, 0, 0}, 0.30e-6, -23.42e-6 }, + {{ 0, 0, 2, -2, 2, 0, 0, 0}, -0.03e-6, -1.46e-6 }, + {{ 0, 0, 2, 0, 2, 0, 0, 0}, -0.01e-6, -0.25e-6 }, + {{ 0, 0, 0, 0, 2, 0, 0, 0}, 0.00e-6, 0.23e-6 } + }; + +/* Terms of order t^4 */ + static const TERM s4[] = { + + /* 1-1 */ + {{ 0, 0, 0, 0, 1, 0, 0, 0}, -0.26e-6, -0.01e-6 } + }; + +/* Number of terms in the series */ + static const int NS0 = (int) (sizeof s0 / sizeof (TERM)); + static const int NS1 = (int) (sizeof s1 / sizeof (TERM)); + static const int NS2 = (int) (sizeof s2 / sizeof (TERM)); + static const int NS3 = (int) (sizeof s3 / sizeof (TERM)); + static const int NS4 = (int) (sizeof s4 / sizeof (TERM)); + +/*--------------------------------------------------------------------*/ + +/* Interval between fundamental epoch J2000.0 and current date (JC). */ + t = ((date1 - ERFA_DJ00) + date2) / ERFA_DJC; + +/* Fundamental Arguments (from IERS Conventions 2003) */ + +/* Mean anomaly of the Moon. */ + fa[0] = eraFal03(t); + +/* Mean anomaly of the Sun. */ + fa[1] = eraFalp03(t); + +/* Mean longitude of the Moon minus that of the ascending node. */ + fa[2] = eraFaf03(t); + +/* Mean elongation of the Moon from the Sun. */ + fa[3] = eraFad03(t); + +/* Mean longitude of the ascending node of the Moon. */ + fa[4] = eraFaom03(t); + +/* Mean longitude of Venus. */ + fa[5] = eraFave03(t); + +/* Mean longitude of Earth. */ + fa[6] = eraFae03(t); + +/* General precession in longitude. */ + fa[7] = eraFapa03(t); + +/* Evaluate s. */ + w0 = sp[0]; + w1 = sp[1]; + w2 = sp[2]; + w3 = sp[3]; + w4 = sp[4]; + w5 = sp[5]; + + for (i = NS0-1; i >= 0; i--) { + a = 0.0; + for (j = 0; j < 8; j++) { + a += (double)s0[i].nfa[j] * fa[j]; + } + w0 += s0[i].s * sin(a) + s0[i].c * cos(a); + } + + for (i = NS1-1; i >= 0; i--) { + a = 0.0; + for (j = 0; j < 8; j++) { + a += (double)s1[i].nfa[j] * fa[j]; + } + w1 += s1[i].s * sin(a) + s1[i].c * cos(a); + } + + for (i = NS2-1; i >= 0; i--) { + a = 0.0; + for (j = 0; j < 8; j++) { + a += (double)s2[i].nfa[j] * fa[j]; + } + w2 += s2[i].s * sin(a) + s2[i].c * cos(a); + } + + for (i = NS3-1; i >= 0; i--) { + a = 0.0; + for (j = 0; j < 8; j++) { + a += (double)s3[i].nfa[j] * fa[j]; + } + w3 += s3[i].s * sin(a) + s3[i].c * cos(a); + } + + for (i = NS4-1; i >= 0; i--) { + a = 0.0; + for (j = 0; j < 8; j++) { + a += (double)s4[i].nfa[j] * fa[j]; + } + w4 += s4[i].s * sin(a) + s4[i].c * cos(a); + } + + s = (w0 + + (w1 + + (w2 + + (w3 + + (w4 + + w5 * t) * t) * t) * t) * t) * ERFA_DAS2R - x*y/2.0; + + return s; + +} +/*---------------------------------------------------------------------- +** +** +** Copyright (C) 2013-2016, NumFOCUS Foundation. +** All rights reserved. +** +** This library is derived, with permission, from the International +** Astronomical Union's "Standards of Fundamental Astronomy" library, +** available from http://www.iausofa.org. +** +** The ERFA version is intended to retain identical functionality to +** the SOFA library, but made distinct through different function and +** file names, as set out in the SOFA license conditions. The SOFA +** original has a role as a reference standard for the IAU and IERS, +** and consequently redistribution is permitted only in its unaltered +** state. The ERFA version is not subject to this restriction and +** therefore can be included in distributions which do not support the +** concept of "read only" software. +** +** Although the intent is to replicate the SOFA API (other than +** replacement of prefix names) and results (with the exception of +** bugs; any that are discovered will be fixed), SOFA is not +** responsible for any errors found in this version of the library. +** +** If you wish to acknowledge the SOFA heritage, please acknowledge +** that you are using a library derived from SOFA, rather than SOFA +** itself. +** +** +** TERMS AND CONDITIONS +** +** Redistribution and use in source and binary forms, with or without +** modification, are permitted provided that the following conditions +** are met: +** +** 1 Redistributions of source code must retain the above copyright +** notice, this list of conditions and the following disclaimer. +** +** 2 Redistributions in binary form must reproduce the above copyright +** notice, this list of conditions and the following disclaimer in +** the documentation and/or other materials provided with the +** distribution. +** +** 3 Neither the name of the Standards Of Fundamental Astronomy Board, +** the International Astronomical Union nor the names of its +** contributors may be used to endorse or promote products derived +** from this software without specific prior written permission. +** +** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS +** FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE +** COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, +** INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, +** BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; +** LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER +** CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT +** LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN +** ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE +** POSSIBILITY OF SUCH DAMAGE. +** +*/ |