#include "sofam.h" void iauBi00(double *dpsibi, double *depsbi, double *dra) /* ** - - - - - - - - ** i a u B i 0 0 ** - - - - - - - - ** ** Frame bias components of IAU 2000 precession-nutation models (part ** of MHB2000 with additions). ** ** This function is part of the International Astronomical Union's ** SOFA (Standards Of Fundamental Astronomy) software collection. ** ** Status: canonical model. ** ** Returned: ** dpsibi,depsbi double longitude and obliquity corrections ** dra double the ICRS RA of the J2000 mean equinox ** ** Notes: ** ** 1) The frame bias corrections in longitude and obliquity (radians) ** are required in order to correct for the offset between the GCRS ** pole and the mean J2000 pole. They define, with respect to the ** GCRS frame, a J2000 mean pole that is consistent with the rest of ** the IAU 2000A precession-nutation model. ** ** 2) In addition to the displacement of the pole, the complete ** description of the frame bias requires also an offset in right ** ascension. This is not part of the IAU 2000A model, and is from ** Chapront et al. (2002). It is returned in radians. ** ** 3) This is a supplemented implementation of one aspect of the IAU ** 2000A nutation model, formally adopted by the IAU General ** Assembly in 2000, namely MHB2000 (Mathews et al. 2002). ** ** References: ** ** Chapront, J., Chapront-Touze, M. & Francou, G., Astron. ** Astrophys., 387, 700, 2002. ** ** Mathews, P.M., Herring, T.A., Buffet, B.A., "Modeling of nutation ** and precession New nutation series for nonrigid Earth and ** insights into the Earth's interior", J.Geophys.Res., 107, B4, ** 2002. The MHB2000 code itself was obtained on 9th September 2002 ** from ftp://maia.usno.navy.mil/conv2000/chapter5/IAU2000A. ** ** This revision: 2008 May 12 ** ** Copyright (C) 2008 IAU SOFA Review Board. See notes at end. */ { /* The frame bias corrections in longitude and obliquity */ const double DPBIAS = -0.041775 * DAS2R, DEBIAS = -0.0068192 * DAS2R; /* The ICRS RA of the J2000 equinox (Chapront et al., 2002) */ const double DRA0 = -0.0146 * DAS2R; /* Return the results (which are fixed). */ *dpsibi = DPBIAS; *depsbi = DEBIAS; *dra = DRA0; return; /*----------------------------------------------------------------------- ** ** 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 ** **---------------------------------------------------------------------*/ }