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author | William Joye <wjoye@cfa.harvard.edu> | 2016-10-17 15:22:52 (GMT) |
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committer | William Joye <wjoye@cfa.harvard.edu> | 2016-10-17 15:22:52 (GMT) |
commit | 7dd9b970cec6832b8f6118dc2dd91a08d2836648 (patch) | |
tree | 4b3c86596ab87f35a3c6213397da07afe1e24d3e /ast/erfa/fk5hip.c | |
parent | d7bf7c61e8507e3cf51f195392c0f41f27ae18d8 (diff) | |
parent | 7fde2daeed593684120d75de07598154f3ddaf2c (diff) | |
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Merge commit '7fde2daeed593684120d75de07598154f3ddaf2c' as 'ast'
Diffstat (limited to 'ast/erfa/fk5hip.c')
-rw-r--r-- | ast/erfa/fk5hip.c | 135 |
1 files changed, 135 insertions, 0 deletions
diff --git a/ast/erfa/fk5hip.c b/ast/erfa/fk5hip.c new file mode 100644 index 0000000..77299f3 --- /dev/null +++ b/ast/erfa/fk5hip.c @@ -0,0 +1,135 @@ +#include "erfa.h" + +void eraFk5hip(double r5h[3][3], double s5h[3]) +/* +** - - - - - - - - - - +** e r a F k 5 h i p +** - - - - - - - - - - +** +** FK5 to Hipparcos rotation and spin. +** +** Returned: +** r5h double[3][3] r-matrix: FK5 rotation wrt Hipparcos (Note 2) +** s5h double[3] r-vector: FK5 spin wrt Hipparcos (Note 3) +** +** Notes: +** +** 1) This function models the FK5 to Hipparcos transformation as a +** pure rotation and spin; zonal errors in the FK5 catalogue are +** not taken into account. +** +** 2) The r-matrix r5h operates in the sense: +** +** P_Hipparcos = r5h x P_FK5 +** +** where P_FK5 is a p-vector in the FK5 frame, and P_Hipparcos is +** the equivalent Hipparcos p-vector. +** +** 3) The r-vector s5h represents the time derivative of the FK5 to +** Hipparcos rotation. The units are radians per year (Julian, +** TDB). +** +** Called: +** eraRv2m r-vector to r-matrix +** +** Reference: +** +** F.Mignard & M.Froeschle, Astron. Astrophys. 354, 732-739 (2000). +** +** Copyright (C) 2013-2014, NumFOCUS Foundation. +** Derived, with permission, from the SOFA library. See notes at end of file. +*/ +{ + double v[3]; + +/* FK5 wrt Hipparcos orientation and spin (radians, radians/year) */ + double epx, epy, epz; + double omx, omy, omz; + + + epx = -19.9e-3 * ERFA_DAS2R; + epy = -9.1e-3 * ERFA_DAS2R; + epz = 22.9e-3 * ERFA_DAS2R; + + omx = -0.30e-3 * ERFA_DAS2R; + omy = 0.60e-3 * ERFA_DAS2R; + omz = 0.70e-3 * ERFA_DAS2R; + +/* FK5 to Hipparcos orientation expressed as an r-vector. */ + v[0] = epx; + v[1] = epy; + v[2] = epz; + +/* Re-express as an r-matrix. */ + eraRv2m(v, r5h); + +/* Hipparcos wrt FK5 spin expressed as an r-vector. */ + s5h[0] = omx; + s5h[1] = omy; + s5h[2] = omz; + + return; + +} +/*---------------------------------------------------------------------- +** +** +** Copyright (C) 2013-2014, 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. +** +*/ |