SUBROUTINE iau_ATCIQZ ( RC, DC, ASTROM, RI, DI ) *+ * - - - - - - - - - - - * i a u _ A T C I Q Z * - - - - - - - - - - - * * Quick ICRS to CIRS transformation, given precomputed star-independent * astrometry parameters, and assuming zero parallax and proper motion. * * Use of this routine 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 * routines iau_APCI[13], iau_APCG[13], iau_APCO[13] or iau_APCS[13]. * * The corresponding routine for the case of non-zero parallax and * proper motion is iau_ATCIQ. * * This routine is part of the International Astronomical Union's * SOFA (Standards of Fundamental Astronomy) software collection. * * Status: support routine. * * Given: * RC,DC d ICRS astrometric RA,Dec (radians) * ASTROM d(30) star-independent astrometry parameters: * (1) PM time interval (SSB, Julian years) * (2-4) SSB to observer (vector, au) * (5-7) Sun to observer (unit vector) * (8) distance from Sun to observer (au) * (9-11) v: barycentric observer velocity (vector, c) * (12) sqrt(1-|v|^2): reciprocal of Lorenz factor * (13-21) bias-precession-nutation matrix * (22) longitude + s' (radians) * (23) polar motion xp wrt local meridian (radians) * (24) polar motion yp wrt local meridian (radians) * (25) sine of geodetic latitude * (26) cosine of geodetic latitude * (27) magnitude of diurnal aberration vector * (28) "local" Earth rotation angle (radians) * (29) refraction constant A (radians) * (30) refraction constant B (radians) * * Returned: * RI,DI d CIRS RA,Dec (radians) * * Note: * * All the vectors are with respect to BCRS axes. * * References: * * Urban, S. & Seidelmann, P. K. (eds), Explanatory Supplement to * the Astronomical Almanac, 3rd ed., University Science Books * (2013). * * Klioner, Sergei A., "A practical relativistic model for micro- * arcsecond astrometry in space", Astr. J. 125, 1580-1597 (2003). * * Called: * iau_S2C spherical coordinates to unit vector * iau_LDSUN light deflection due to Sun * iau_AB stellar aberration * iau_RXP product of r-matrix and p-vector * iau_C2S p-vector to spherical * iau_ANP normalize angle into range +/- pi * * This revision: 2013 August 31 * * SOFA release 2021-05-12 * * Copyright (C) 2021 IAU SOFA Board. See notes at end. * *----------------------------------------------------------------------- IMPLICIT NONE DOUBLE PRECISION RC, DC, ASTROM(30), RI, DI DOUBLE PRECISION PCO(3), PNAT(3), PPR(3), PI(3), W DOUBLE PRECISION iau_ANP * - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - * BCRS coordinate direction (unit vector). CALL iau_S2C ( RC, DC, PCO ) * Light deflection by the Sun, giving BCRS natural direction. CALL iau_LDSUN ( PCO, ASTROM(5), ASTROM(8), PNAT ) * Aberration, giving GCRS proper direction. CALL iau_AB ( PNAT, ASTROM(9), ASTROM(8), ASTROM(12), PPR ) * Bias-precession-nutation, giving CIRS proper direction. CALL iau_RXP ( ASTROM(13), PPR, PI ) * CIRS RA,Dec. CALL iau_C2S ( PI, W, DI ) RI = iau_ANP ( W ) * Finished. *+---------------------------------------------------------------------- * * Copyright (C) 2021 * 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 * *----------------------------------------------------------------------- END