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author | William Joye <wjoye@cfa.harvard.edu> | 2018-01-09 19:06:55 (GMT) |
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committer | William Joye <wjoye@cfa.harvard.edu> | 2018-01-09 19:06:55 (GMT) |
commit | 01e0ebfe59d9028b0246ec4a549bd7528ada94eb (patch) | |
tree | a6c5b54db03177a1c8f3e7fb531990dfbc7bae39 /ast/erfa/p06e.c | |
parent | d64cf9c0bd23e752867b149be636d1bbd4501cf4 (diff) | |
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update ast 8.6.2
Diffstat (limited to 'ast/erfa/p06e.c')
-rw-r--r-- | ast/erfa/p06e.c | 330 |
1 files changed, 330 insertions, 0 deletions
diff --git a/ast/erfa/p06e.c b/ast/erfa/p06e.c new file mode 100644 index 0000000..24f9f2b --- /dev/null +++ b/ast/erfa/p06e.c @@ -0,0 +1,330 @@ +#include "erfa.h" + +void eraP06e(double date1, double date2, + double *eps0, double *psia, double *oma, double *bpa, + double *bqa, double *pia, double *bpia, + double *epsa, double *chia, double *za, double *zetaa, + double *thetaa, double *pa, + double *gam, double *phi, double *psi) +/* +** - - - - - - - - +** e r a P 0 6 e +** - - - - - - - - +** +** Precession angles, IAU 2006, equinox based. +** +** Given: +** date1,date2 double TT as a 2-part Julian Date (Note 1) +** +** Returned (see Note 2): +** eps0 double epsilon_0 +** psia double psi_A +** oma double omega_A +** bpa double P_A +** bqa double Q_A +** pia double pi_A +** bpia double Pi_A +** epsa double obliquity epsilon_A +** chia double chi_A +** za double z_A +** zetaa double zeta_A +** thetaa double theta_A +** pa double p_A +** gam double F-W angle gamma_J2000 +** phi double F-W angle phi_J2000 +** psi double F-W angle psi_J2000 +** +** 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) This function returns the set of equinox based angles for the +** Capitaine et al. "P03" precession theory, adopted by the IAU in +** 2006. The angles are set out in Table 1 of Hilton et al. (2006): +** +** eps0 epsilon_0 obliquity at J2000.0 +** psia psi_A luni-solar precession +** oma omega_A inclination of equator wrt J2000.0 ecliptic +** bpa P_A ecliptic pole x, J2000.0 ecliptic triad +** bqa Q_A ecliptic pole -y, J2000.0 ecliptic triad +** pia pi_A angle between moving and J2000.0 ecliptics +** bpia Pi_A longitude of ascending node of the ecliptic +** epsa epsilon_A obliquity of the ecliptic +** chia chi_A planetary precession +** za z_A equatorial precession: -3rd 323 Euler angle +** zetaa zeta_A equatorial precession: -1st 323 Euler angle +** thetaa theta_A equatorial precession: 2nd 323 Euler angle +** pa p_A general precession +** gam gamma_J2000 J2000.0 RA difference of ecliptic poles +** phi phi_J2000 J2000.0 codeclination of ecliptic pole +** psi psi_J2000 longitude difference of equator poles, J2000.0 +** +** The returned values are all radians. +** +** 3) Hilton et al. (2006) Table 1 also contains angles that depend on +** models distinct from the P03 precession theory itself, namely the +** IAU 2000A frame bias and nutation. The quoted polynomials are +** used in other ERFA functions: +** +** . eraXy06 contains the polynomial parts of the X and Y series. +** +** . eraS06 contains the polynomial part of the s+XY/2 series. +** +** . eraPfw06 implements the series for the Fukushima-Williams +** angles that are with respect to the GCRS pole (i.e. the variants +** that include frame bias). +** +** 4) The IAU resolution stipulated that the choice of parameterization +** was left to the user, and so an IAU compliant precession +** implementation can be constructed using various combinations of +** the angles returned by the present function. +** +** 5) The parameterization used by ERFA is the version of the Fukushima- +** Williams angles that refers directly to the GCRS pole. These +** angles may be calculated by calling the function eraPfw06. ERFA +** also supports the direct computation of the CIP GCRS X,Y by +** series, available by calling eraXy06. +** +** 6) The agreement between the different parameterizations is at the +** 1 microarcsecond level in the present era. +** +** 7) When constructing a precession formulation that refers to the GCRS +** pole rather than the dynamical pole, it may (depending on the +** choice of angles) be necessary to introduce the frame bias +** explicitly. +** +** 8) It is permissible to re-use the same variable in the returned +** arguments. The quantities are stored in the stated order. +** +** Reference: +** +** Hilton, J. et al., 2006, Celest.Mech.Dyn.Astron. 94, 351 +** +** Called: +** eraObl06 mean obliquity, IAU 2006 +** +** Copyright (C) 2013-2016, NumFOCUS Foundation. +** Derived, with permission, from the SOFA library. See notes at end of file. +*/ +{ + double t; + + +/* Interval between fundamental date J2000.0 and given date (JC). */ + t = ((date1 - ERFA_DJ00) + date2) / ERFA_DJC; + +/* Obliquity at J2000.0. */ + + *eps0 = 84381.406 * ERFA_DAS2R; + +/* Luni-solar precession. */ + + *psia = ( 5038.481507 + + ( -1.0790069 + + ( -0.00114045 + + ( 0.000132851 + + ( -0.0000000951 ) + * t) * t) * t) * t) * t * ERFA_DAS2R; + +/* Inclination of mean equator with respect to the J2000.0 ecliptic. */ + + *oma = *eps0 + ( -0.025754 + + ( 0.0512623 + + ( -0.00772503 + + ( -0.000000467 + + ( 0.0000003337 ) + * t) * t) * t) * t) * t * ERFA_DAS2R; + +/* Ecliptic pole x, J2000.0 ecliptic triad. */ + + *bpa = ( 4.199094 + + ( 0.1939873 + + ( -0.00022466 + + ( -0.000000912 + + ( 0.0000000120 ) + * t) * t) * t) * t) * t * ERFA_DAS2R; + +/* Ecliptic pole -y, J2000.0 ecliptic triad. */ + + *bqa = ( -46.811015 + + ( 0.0510283 + + ( 0.00052413 + + ( -0.000000646 + + ( -0.0000000172 ) + * t) * t) * t) * t) * t * ERFA_DAS2R; + +/* Angle between moving and J2000.0 ecliptics. */ + + *pia = ( 46.998973 + + ( -0.0334926 + + ( -0.00012559 + + ( 0.000000113 + + ( -0.0000000022 ) + * t) * t) * t) * t) * t * ERFA_DAS2R; + +/* Longitude of ascending node of the moving ecliptic. */ + + *bpia = ( 629546.7936 + + ( -867.95758 + + ( 0.157992 + + ( -0.0005371 + + ( -0.00004797 + + ( 0.000000072 ) + * t) * t) * t) * t) * t) * ERFA_DAS2R; + +/* Mean obliquity of the ecliptic. */ + + *epsa = eraObl06(date1, date2); + +/* Planetary precession. */ + + *chia = ( 10.556403 + + ( -2.3814292 + + ( -0.00121197 + + ( 0.000170663 + + ( -0.0000000560 ) + * t) * t) * t) * t) * t * ERFA_DAS2R; + +/* Equatorial precession: minus the third of the 323 Euler angles. */ + + *za = ( -2.650545 + + ( 2306.077181 + + ( 1.0927348 + + ( 0.01826837 + + ( -0.000028596 + + ( -0.0000002904 ) + * t) * t) * t) * t) * t) * ERFA_DAS2R; + +/* Equatorial precession: minus the first of the 323 Euler angles. */ + + *zetaa = ( 2.650545 + + ( 2306.083227 + + ( 0.2988499 + + ( 0.01801828 + + ( -0.000005971 + + ( -0.0000003173 ) + * t) * t) * t) * t) * t) * ERFA_DAS2R; + +/* Equatorial precession: second of the 323 Euler angles. */ + + *thetaa = ( 2004.191903 + + ( -0.4294934 + + ( -0.04182264 + + ( -0.000007089 + + ( -0.0000001274 ) + * t) * t) * t) * t) * t * ERFA_DAS2R; + +/* General precession. */ + + *pa = ( 5028.796195 + + ( 1.1054348 + + ( 0.00007964 + + ( -0.000023857 + + ( 0.0000000383 ) + * t) * t) * t) * t) * t * ERFA_DAS2R; + +/* Fukushima-Williams angles for precession. */ + + *gam = ( 10.556403 + + ( 0.4932044 + + ( -0.00031238 + + ( -0.000002788 + + ( 0.0000000260 ) + * t) * t) * t) * t) * t * ERFA_DAS2R; + + *phi = *eps0 + ( -46.811015 + + ( 0.0511269 + + ( 0.00053289 + + ( -0.000000440 + + ( -0.0000000176 ) + * t) * t) * t) * t) * t * ERFA_DAS2R; + + *psi = ( 5038.481507 + + ( 1.5584176 + + ( -0.00018522 + + ( -0.000026452 + + ( -0.0000000148 ) + * t) * t) * t) * t) * t * ERFA_DAS2R; + + 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. +** +*/ |