#include "sofa.h" void iauAtciq(double rc, double dc, double pr, double pd, double px, double rv, iauASTROM *astrom, double *ri, double *di) /* ** - - - - - - - - - ** i a u A t c i q ** - - - - - - - - - ** ** Quick ICRS, epoch J2000.0, to CIRS transformation, given precomputed ** star-independent astrometry parameters. ** ** Use of this function is appropriate when efficiency is important and ** where many star positions are to be transformed for one date. The ** star-independent parameters can be obtained by calling one of the ** functions iauApci[13], iauApcg[13], iauApco[13] or iauApcs[13]. ** ** If the parallax and proper motions are zero the iauAtciqz function ** can be used instead. ** ** This function is part of the International Astronomical Union's ** SOFA (Standards of Fundamental Astronomy) software collection. ** ** Status: support function. ** ** Given: ** rc,dc double ICRS RA,Dec at J2000.0 (radians) ** pr double RA proper motion (radians/year; Note 3) ** pd double Dec proper motion (radians/year) ** px double parallax (arcsec) ** rv double radial velocity (km/s, +ve if receding) ** astrom iauASTROM* star-independent astrometry parameters: ** pmt double PM time interval (SSB, Julian years) ** eb double[3] SSB to observer (vector, au) ** eh double[3] Sun to observer (unit vector) ** em double distance from Sun to observer (au) ** v double[3] barycentric observer velocity (vector, c) ** bm1 double sqrt(1-|v|^2): reciprocal of Lorenz factor ** bpn double[3][3] bias-precession-nutation matrix ** along double longitude + s' (radians) ** xpl double polar motion xp wrt local meridian (radians) ** ypl double polar motion yp wrt local meridian (radians) ** sphi double sine of geodetic latitude ** cphi double cosine of geodetic latitude ** diurab double magnitude of diurnal aberration vector ** eral double "local" Earth rotation angle (radians) ** refa double refraction constant A (radians) ** refb double refraction constant B (radians) ** ** Returned: ** ri,di double CIRS RA,Dec (radians) ** ** Notes: ** ** 1) All the vectors are with respect to BCRS axes. ** ** 2) Star data for an epoch other than J2000.0 (for example from the ** Hipparcos catalog, which has an epoch of J1991.25) will require a ** preliminary call to iauPmsafe before use. ** ** 3) The proper motion in RA is dRA/dt rather than cos(Dec)*dRA/dt. ** ** Called: ** iauPmpx proper motion and parallax ** iauLdsun light deflection by the Sun ** iauAb stellar aberration ** iauRxp product of r-matrix and pv-vector ** iauC2s p-vector to spherical ** iauAnp normalize angle into range 0 to 2pi ** ** This revision: 2013 October 9 ** ** SOFA release 2013-12-02 ** ** Copyright (C) 2013 IAU SOFA Board. See notes at end. */ { double pco[3], pnat[3], ppr[3], pi[3], w; /* Proper motion and parallax, giving BCRS coordinate direction. */ iauPmpx(rc, dc, pr, pd, px, rv, astrom->pmt, astrom->eb, pco); /* Light deflection by the Sun, giving BCRS natural direction. */ iauLdsun(pco, astrom->eh, astrom->em, pnat); /* Aberration, giving GCRS proper direction. */ iauAb(pnat, astrom->v, astrom->em, astrom->bm1, ppr); /* Bias-precession-nutation, giving CIRS proper direction. */ iauRxp(astrom->bpn, ppr, pi); /* CIRS RA,Dec. */ iauC2s(pi, &w, di); *ri = iauAnp(w); /* Finished. */ /*---------------------------------------------------------------------- ** ** Copyright (C) 2013 ** Standards Of Fundamental Astronomy Board ** of the International Astronomical Union. ** ** ===================== ** SOFA Software License ** ===================== ** ** NOTICE TO USER: ** ** BY USING THIS SOFTWARE YOU ACCEPT THE FOLLOWING SIX TERMS AND ** CONDITIONS WHICH APPLY TO ITS USE. ** ** 1. The Software is owned by the IAU SOFA Board ("SOFA"). ** ** 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 distribute SOFA source code to others, ** and use and adapt its code and algorithms in your own software, ** on a world-wide, royalty-free basis. That portion of your ** distribution that does not consist of intact and unchanged copies ** of SOFA source code files is a "derived work" that must comply ** 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 itself constitute software provided by and/or ** endorsed by SOFA. ** ** b) The source code of your derived work must contain descriptions ** of how the derived work is based upon, contains and/or differs ** from the original SOFA software. ** ** c) The names of all routines in your derived work shall not ** include the prefix "iau" or "sofa" or trivial modifications ** thereof such as changes of case. ** ** d) 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. ** ** e) 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. ** ** Note that, as originally distributed, the SOFA software is ** intended to be a definitive implementation of the IAU standards, ** and consequently third-party modifications are discouraged. All ** variations, no matter how minor, must be explicitly marked as ** such, as explained above. ** ** 4. You shall not cause the SOFA software to be brought into ** disrepute, either by misuse, or use for inappropriate tasks, or ** by inappropriate modification. ** ** 5. The SOFA software is provided "as is" and SOFA makes no warranty ** as to its use or performance. SOFA does not and cannot warrant ** the performance or results which the user may obtain by using the ** SOFA software. SOFA 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 SOFA be ** liable to the user for any consequential, incidental, or special ** damages, including any lost profits or lost savings, even if a ** SOFA representative has been advised of such damages, or for any ** claim by any third party. ** ** 6. 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. * ** In any published work or commercial product which uses the SOFA ** software directly, acknowledgement (see www.iausofa.org) is ** appreciated. ** ** Correspondence concerning SOFA software should be addressed as ** follows: ** ** By email: sofa@ukho.gov.uk ** By post: IAU SOFA Center ** HM Nautical Almanac Office ** UK Hydrographic Office ** Admiralty Way, Taunton ** Somerset, TA1 2DN ** United Kingdom ** **--------------------------------------------------------------------*/ }