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Diffstat (limited to 'ast/erfa/pnm00b.c')
-rw-r--r-- | ast/erfa/pnm00b.c | 130 |
1 files changed, 130 insertions, 0 deletions
diff --git a/ast/erfa/pnm00b.c b/ast/erfa/pnm00b.c new file mode 100644 index 0000000..9acecbe --- /dev/null +++ b/ast/erfa/pnm00b.c @@ -0,0 +1,130 @@ +#include "erfa.h" + +void eraPnm00b(double date1, double date2, double rbpn[3][3]) +/* +** - - - - - - - - - - +** e r a P n m 0 0 b +** - - - - - - - - - - +** +** Form the matrix of precession-nutation for a given date (including +** frame bias), equinox-based, IAU 2000B model. +** +** Given: +** date1,date2 double TT as a 2-part Julian Date (Note 1) +** +** Returned: +** rbpn double[3][3] bias-precession-nutation matrix (Note 2) +** +** Notes: +** +** 1) The TT date date1+date2 is a Julian Date, apportioned in any +** convenient way between the two arguments. For example, +** JD(TT)=2450123.7 could be expressed in any of these ways, +** among others: +** +** date1 date2 +** +** 2450123.7 0.0 (JD method) +** 2451545.0 -1421.3 (J2000 method) +** 2400000.5 50123.2 (MJD method) +** 2450123.5 0.2 (date & time method) +** +** The JD method is the most natural and convenient to use in +** cases where the loss of several decimal digits of resolution +** is acceptable. The J2000 method is best matched to the way +** the argument is handled internally and will deliver the +** optimum resolution. The MJD method and the date & time methods +** are both good compromises between resolution and convenience. +** +** 2) The matrix operates in the sense V(date) = rbpn * V(GCRS), where +** the p-vector V(date) is with respect to the true equatorial triad +** of date date1+date2 and the p-vector V(GCRS) is with respect to +** the Geocentric Celestial Reference System (IAU, 2000). +** +** 3) The present function is faster, but slightly less accurate (about +** 1 mas), than the eraPnm00a function. +** +** Called: +** eraPn00b bias/precession/nutation, IAU 2000B +** +** Reference: +** +** IAU: Trans. International Astronomical Union, Vol. XXIVB; Proc. +** 24th General Assembly, Manchester, UK. Resolutions B1.3, B1.6. +** (2000) +** +** Copyright (C) 2013-2014, NumFOCUS Foundation. +** Derived, with permission, from the SOFA library. See notes at end of file. +*/ +{ + double dpsi, deps, epsa, rb[3][3], rp[3][3], rbp[3][3], rn[3][3]; + + +/* Obtain the required matrix (discarding other results). */ + eraPn00b(date1, date2, &dpsi, &deps, &epsa, rb, rp, rbp, rn, rbpn); + + 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. +** +*/ |