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Diffstat (limited to 'ast/erfa/aper13.c')
| -rw-r--r-- | ast/erfa/aper13.c | 181 |
1 files changed, 181 insertions, 0 deletions
diff --git a/ast/erfa/aper13.c b/ast/erfa/aper13.c new file mode 100644 index 0000000..e2b019c --- /dev/null +++ b/ast/erfa/aper13.c @@ -0,0 +1,181 @@ +#include "erfa.h" + +void eraAper13(double ut11, double ut12, eraASTROM *astrom) +/* +** - - - - - - - - - - +** e r a A p e r 1 3 +** - - - - - - - - - - +** +** In the star-independent astrometry parameters, update only the +** Earth rotation angle. The caller provides UT1, (n.b. not UTC). +** +** Given: +** ut11 double UT1 as a 2-part... +** ut12 double ...Julian Date (Note 1) +** astrom eraASTROM* star-independent astrometry parameters: +** pmt double not used +** eb double[3] not used +** eh double[3] not used +** em double not used +** v double[3] not used +** bm1 double not used +** bpn double[3][3] not used +** along double longitude + s' (radians) +** xpl double not used +** ypl double not used +** sphi double not used +** cphi double not used +** diurab double not used +** eral double not used +** refa double not used +** refb double not used +** +** Returned: +** astrom eraASTROM* star-independent astrometry parameters: +** pmt double unchanged +** eb double[3] unchanged +** eh double[3] unchanged +** em double unchanged +** v double[3] unchanged +** bm1 double unchanged +** bpn double[3][3] unchanged +** along double unchanged +** xpl double unchanged +** ypl double unchanged +** sphi double unchanged +** cphi double unchanged +** diurab double unchanged +** eral double "local" Earth rotation angle (radians) +** refa double unchanged +** refb double unchanged +** +** Notes: +** +** 1) The UT1 date (n.b. not UTC) ut11+ut12 is a Julian Date, +** apportioned in any convenient way between the arguments ut11 and +** ut12. For example, JD(UT1)=2450123.7 could be expressed in any +** of these ways, among others: +** +** ut11 ut12 +** +** 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 and MJD methods are good compromises +** between resolution and convenience. The date & time method is +** best matched to the algorithm used: maximum precision is +** delivered when the ut11 argument is for 0hrs UT1 on the day in +** question and the ut12 argument lies in the range 0 to 1, or vice +** versa. +** +** 2) If the caller wishes to provide the Earth rotation angle itself, +** the function eraAper can be used instead. One use of this +** technique is to substitute Greenwich apparent sidereal time and +** thereby to support equinox based transformations directly. +** +** 3) This is one of several functions that inserts into the astrom +** structure star-independent parameters needed for the chain of +** astrometric transformations ICRS <-> GCRS <-> CIRS <-> observed. +** +** The various functions support different classes of observer and +** portions of the transformation chain: +** +** functions observer transformation +** +** eraApcg eraApcg13 geocentric ICRS <-> GCRS +** eraApci eraApci13 terrestrial ICRS <-> CIRS +** eraApco eraApco13 terrestrial ICRS <-> observed +** eraApcs eraApcs13 space ICRS <-> GCRS +** eraAper eraAper13 terrestrial update Earth rotation +** eraApio eraApio13 terrestrial CIRS <-> observed +** +** Those with names ending in "13" use contemporary ERFA models to +** compute the various ephemerides. The others accept ephemerides +** supplied by the caller. +** +** The transformation from ICRS to GCRS covers space motion, +** parallax, light deflection, and aberration. From GCRS to CIRS +** comprises frame bias and precession-nutation. From CIRS to +** observed takes account of Earth rotation, polar motion, diurnal +** aberration and parallax (unless subsumed into the ICRS <-> GCRS +** transformation), and atmospheric refraction. +** +** Called: +** eraAper astrometry parameters: update ERA +** eraEra00 Earth rotation angle, IAU 2000 +** +** Copyright (C) 2013-2016, NumFOCUS Foundation. +** Derived, with permission, from the SOFA library. See notes at end of file. +*/ +{ + eraAper(eraEra00(ut11,ut12), astrom); + +/* Finished. */ + +} +/*---------------------------------------------------------------------- +** +** +** 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. +** +*/ |