#include "erfa.h" void eraAtciqn(double rc, double dc, double pr, double pd, double px, double rv, eraASTROM *astrom, int n, eraLDBODY b[], double *ri, double *di) /* ** - - - - - - - - - - ** e r a A t c i q n ** - - - - - - - - - - ** ** Quick ICRS, epoch J2000.0, to CIRS transformation, given precomputed ** star-independent astrometry parameters plus a list of light- ** deflecting bodies. ** ** 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 eraApci[13], eraApcg[13], eraApco[13] or eraApcs[13]. ** ** If the only light-deflecting body to be taken into account is the ** Sun, the eraAtciq function can be used instead. If in addition the ** parallax and proper motions are zero, the eraAtciqz function can be ** used. ** ** 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 eraASTROM* 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) ** n int number of bodies (Note 3) ** b eraLDBODY[n] data for each of the n bodies (Notes 3,4): ** bm double mass of the body (solar masses, Note 5) ** dl double deflection limiter (Note 6) ** pv [2][3] barycentric PV of the body (au, au/day) ** ** Returned: ** ri,di double CIRS RA,Dec (radians) ** ** Notes: ** ** 1) 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 eraPmsafe before use. ** ** 2) The proper motion in RA is dRA/dt rather than cos(Dec)*dRA/dt. ** ** 3) The struct b contains n entries, one for each body to be ** considered. If n = 0, no gravitational light deflection will be ** applied, not even for the Sun. ** ** 4) The struct b should include an entry for the Sun as well as for ** any planet or other body to be taken into account. The entries ** should be in the order in which the light passes the body. ** ** 5) In the entry in the b struct for body i, the mass parameter ** b[i].bm can, as required, be adjusted in order to allow for such ** effects as quadrupole field. ** ** 6) The deflection limiter parameter b[i].dl is phi^2/2, where phi is ** the angular separation (in radians) between star and body at ** which limiting is applied. As phi shrinks below the chosen ** threshold, the deflection is artificially reduced, reaching zero ** for phi = 0. Example values suitable for a terrestrial ** observer, together with masses, are as follows: ** ** body i b[i].bm b[i].dl ** ** Sun 1.0 6e-6 ** Jupiter 0.00095435 3e-9 ** Saturn 0.00028574 3e-10 ** ** 7) For efficiency, validation of the contents of the b array is ** omitted. The supplied masses must be greater than zero, the ** position and velocity vectors must be right, and the deflection ** limiter greater than zero. ** ** Called: ** eraPmpx proper motion and parallax ** eraLdn light deflection by n bodies ** eraAb stellar aberration ** eraRxp product of r-matrix and pv-vector ** eraC2s p-vector to spherical ** eraAnp normalize angle into range 0 to 2pi ** ** Copyright (C) 2013-2015, NumFOCUS Foundation. ** Derived, with permission, from the SOFA library. See notes at end of file. */ { double pco[3], pnat[3], ppr[3], pi[3], w; /* Proper motion and parallax, giving BCRS coordinate direction. */ eraPmpx(rc, dc, pr, pd, px, rv, astrom->pmt, astrom->eb, pco); /* Light deflection, giving BCRS natural direction. */ eraLdn(n, b, astrom->eb, pco, pnat); /* Aberration, giving GCRS proper direction. */ eraAb(pnat, astrom->v, astrom->em, astrom->bm1, ppr); /* Bias-precession-nutation, giving CIRS proper direction. */ eraRxp(astrom->bpn, ppr, pi); /* CIRS RA,Dec. */ eraC2s(pi, &w, di); *ri = eraAnp(w); /* Finished. */ } /*---------------------------------------------------------------------- ** ** ** Copyright (C) 2013-2015, 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. ** */