#include "sofam.h" double iauS06(double date1, double date2, double x, double y) /* ** - - - - - - - ** i a u 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. ** ** This function is part of the International Astronomical Union's ** SOFA (Standards Of Fundamental Astronomy) software collection. ** ** Status: canonical model. ** ** 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: ** iauFal03 mean anomaly of the Moon ** iauFalp03 mean anomaly of the Sun ** iauFaf03 mean argument of the latitude of the Moon ** iauFad03 mean elongation of the Moon from the Sun ** iauFaom03 mean longitude of the Moon's ascending node ** iauFave03 mean longitude of Venus ** iauFae03 mean longitude of Earth ** iauFapa03 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 ** ** This revision: 2008 September 30 ** ** Copyright (C) 2008 IAU SOFA Review Board. See notes at end. */ { /* Time since J2000, 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 */ 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 */ 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 */ 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 */ 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 */ 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 */ TERM s4[] = { /* 1-1 */ {{ 0, 0, 0, 0, 1, 0, 0, 0}, -0.26e-6, -0.01e-6 } }; /* Number of terms in the series */ const int NS0 = (int) (sizeof s0 / sizeof (TERM)); const int NS1 = (int) (sizeof s1 / sizeof (TERM)); const int NS2 = (int) (sizeof s2 / sizeof (TERM)); const int NS3 = (int) (sizeof s3 / sizeof (TERM)); const int NS4 = (int) (sizeof s4 / sizeof (TERM)); /*--------------------------------------------------------------------*/ /* Interval between fundamental epoch J2000.0 and current date (JC). */ t = ((date1 - DJ00) + date2) / DJC; /* Fundamental Arguments (from IERS Conventions 2003) */ /* Mean anomaly of the Moon. */ fa[0] = iauFal03(t); /* Mean anomaly of the Sun. */ fa[1] = iauFalp03(t); /* Mean longitude of the Moon minus that of the ascending node. */ fa[2] = iauFaf03(t); /* Mean elongation of the Moon from the Sun. */ fa[3] = iauFad03(t); /* Mean longitude of the ascending node of the Moon. */ fa[4] = iauFaom03(t); /* Mean longitude of Venus. */ fa[5] = iauFave03(t); /* Mean longitude of Earth. */ fa[6] = iauFae03(t); /* General precession in longitude. */ fa[7] = iauFapa03(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) * DAS2R - x*y/2.0; return s; /*----------------------------------------------------------------------- ** ** Copyright (C) 2008 ** Standards Of Fundamental Astronomy Review Board ** of the International Astronomical Union. ** ** ===================== ** SOFA Software License ** ===================== ** ** NOTICE TO USER: ** ** BY USING THIS SOFTWARE YOU ACCEPT THE FOLLOWING TERMS AND CONDITIONS ** WHICH APPLY TO ITS USE. ** ** 1. The Software is owned by the IAU SOFA Review Board ("the Board"). ** ** 2. Permission is granted to anyone to use the SOFA software for any ** purpose, including commercial applications, free of charge and ** without payment of royalties, subject to the conditions and ** restrictions listed below. ** ** 3. You (the user) may copy and adapt the SOFA software and its ** algorithms for your own purposes and you may copy and distribute ** a resulting "derived work" to others on a world-wide, royalty-free ** basis, provided that the derived work complies with the following ** requirements: ** ** a) Your work shall be marked or carry a statement that it (i) uses ** routines and computations derived by you from software provided ** by SOFA under license to you; and (ii) does not contain ** software provided by SOFA or software that has been distributed ** by or endorsed by SOFA. ** ** b) The source code of your derived work must contain descriptions ** of how the derived work is based upon and/or differs from the ** original SOFA software. ** ** c) The name(s) of all routine(s) that you distribute shall differ ** from the SOFA names, even when the SOFA content has not been ** otherwise changed. ** ** d) The routine-naming prefix "iau" shall not be used. ** ** e) The origin of the SOFA components of your derived work must not ** be misrepresented; you must not claim that you wrote the ** original software, nor file a patent application for SOFA ** software or algorithms embedded in the SOFA software. ** ** f) These requirements must be reproduced intact in any source ** distribution and shall apply to anyone to whom you have granted ** a further right to modify the source code of your derived work. ** ** 4. In any published work or commercial products which includes ** results achieved by using the SOFA software, you shall acknowledge ** that the SOFA software was used in obtaining those results. ** ** 5. You shall not cause the SOFA software to be brought into ** disrepute, either by misuse, or use for inappropriate tasks, or by ** inappropriate modification. ** ** 6. The SOFA software is provided "as is" and the Board makes no ** warranty as to its use or performance. The Board does not and ** cannot warrant the performance or results which the user may obtain ** by using the SOFA software. The Board makes no warranties, express ** or implied, as to non-infringement of third party rights, ** merchantability, or fitness for any particular purpose. In no ** event will the Board be liable to the user for any consequential, ** incidental, or special damages, including any lost profits or lost ** savings, even if a Board representative has been advised of such ** damages, or for any claim by any third party. ** ** 7. The provision of any version of the SOFA software under the terms ** and conditions specified herein does not imply that future ** versions will also be made available under the same terms and ** conditions. ** ** Correspondence concerning SOFA software should be addressed as ** follows: ** ** Internet email: sofa@rl.ac.uk ** Postal address: IAU SOFA Center ** Rutherford Appleton Laboratory ** Chilton, Didcot, Oxon OX11 0QX ** United Kingdom ** **---------------------------------------------------------------------*/ }