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author | William Joye <wjoye@cfa.harvard.edu> | 2019-05-10 16:18:58 (GMT) |
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committer | William Joye <wjoye@cfa.harvard.edu> | 2019-05-10 16:18:58 (GMT) |
commit | 5492ad5105428df25cca70ab260229f757427278 (patch) | |
tree | e2bc900ba8c297d483518d1e86405e2e0f86f0ea /ast/erfa/pom00.c | |
parent | 9646e8d50bc1481de77459d59738826f9c256ad6 (diff) | |
download | blt-5492ad5105428df25cca70ab260229f757427278.zip blt-5492ad5105428df25cca70ab260229f757427278.tar.gz blt-5492ad5105428df25cca70ab260229f757427278.tar.bz2 |
upgrade ast 8.7.1
Diffstat (limited to 'ast/erfa/pom00.c')
-rw-r--r-- | ast/erfa/pom00.c | 124 |
1 files changed, 124 insertions, 0 deletions
diff --git a/ast/erfa/pom00.c b/ast/erfa/pom00.c new file mode 100644 index 0000000..0f61496 --- /dev/null +++ b/ast/erfa/pom00.c @@ -0,0 +1,124 @@ +#include "erfa.h" + +void eraPom00(double xp, double yp, double sp, double rpom[3][3]) +/* +** - - - - - - - - - - +** e r a P o m 0 0 +** - - - - - - - - - - +** +** Form the matrix of polar motion for a given date, IAU 2000. +** +** Given: +** xp,yp double coordinates of the pole (radians, Note 1) +** sp double the TIO locator s' (radians, Note 2) +** +** Returned: +** rpom double[3][3] polar-motion matrix (Note 3) +** +** Notes: +** +** 1) The arguments xp and yp are the coordinates (in radians) of the +** Celestial Intermediate Pole with respect to the International +** Terrestrial Reference System (see IERS Conventions 2003), +** measured along the meridians to 0 and 90 deg west respectively. +** +** 2) The argument sp is the TIO locator s', in radians, which +** positions the Terrestrial Intermediate Origin on the equator. It +** is obtained from polar motion observations by numerical +** integration, and so is in essence unpredictable. However, it is +** dominated by a secular drift of about 47 microarcseconds per +** century, and so can be taken into account by using s' = -47*t, +** where t is centuries since J2000.0. The function eraSp00 +** implements this approximation. +** +** 3) The matrix operates in the sense V(TRS) = rpom * V(CIP), meaning +** that it is the final rotation when computing the pointing +** direction to a celestial source. +** +** Called: +** eraIr initialize r-matrix to identity +** eraRz rotate around Z-axis +** eraRy rotate around Y-axis +** eraRx rotate around X-axis +** +** Reference: +** +** McCarthy, D. D., Petit, G. (eds.), IERS Conventions (2003), +** IERS Technical Note No. 32, BKG (2004) +** +** Copyright (C) 2013-2016, NumFOCUS Foundation. +** Derived, with permission, from the SOFA library. See notes at end of file. +*/ +{ + +/* Construct the matrix. */ + eraIr(rpom); + eraRz(sp, rpom); + eraRy(-xp, rpom); + eraRx(-yp, rpom); + + return; + +} +/*---------------------------------------------------------------------- +** +** +** Copyright (C) 2013-2016, 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. +** +*/ |