223 lines
9.0 KiB
C
223 lines
9.0 KiB
C
#include "sofa.h"
|
|
|
|
void iauAper13(double ut11, double ut12, iauASTROM *astrom)
|
|
/*
|
|
** - - - - - - - - - -
|
|
** i a u 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).
|
|
**
|
|
** This function is part of the International Astronomical Union's
|
|
** SOFA (Standards of Fundamental Astronomy) software collection.
|
|
**
|
|
** Status: support function.
|
|
**
|
|
** Given:
|
|
** ut11 double UT1 as a 2-part...
|
|
** ut12 double ...Julian Date (Note 1)
|
|
** astrom iauASTROM* 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 iauASTROM* 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 iauAper 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
|
|
**
|
|
** iauApcg iauApcg13 geocentric ICRS <-> GCRS
|
|
** iauApci iauApci13 terrestrial ICRS <-> CIRS
|
|
** iauApco iauApco13 terrestrial ICRS <-> observed
|
|
** iauApcs iauApcs13 space ICRS <-> GCRS
|
|
** iauAper iauAper13 terrestrial update Earth rotation
|
|
** iauApio iauApio13 terrestrial CIRS <-> observed
|
|
**
|
|
** Those with names ending in "13" use contemporary SOFA 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:
|
|
** iauAper astrometry parameters: update ERA
|
|
** iauEra00 Earth rotation angle, IAU 2000
|
|
**
|
|
** This revision: 2013 September 25
|
|
**
|
|
** SOFA release 2020-07-21
|
|
**
|
|
** Copyright (C) 2020 IAU SOFA Board. See notes at end.
|
|
*/
|
|
{
|
|
iauAper(iauEra00(ut11,ut12), astrom);
|
|
|
|
/* Finished. */
|
|
|
|
/*----------------------------------------------------------------------
|
|
**
|
|
** Copyright (C) 2020
|
|
** Standards Of Fundamental Astronomy Board
|
|
** of the International Astronomical Union.
|
|
**
|
|
** =====================
|
|
** SOFA Software License
|
|
** =====================
|
|
**
|
|
** NOTICE TO USER:
|
|
**
|
|
** BY USING THIS SOFTWARE YOU ACCEPT THE FOLLOWING SIX TERMS AND
|
|
** CONDITIONS WHICH APPLY TO ITS USE.
|
|
**
|
|
** 1. The Software is owned by the IAU SOFA Board ("SOFA").
|
|
**
|
|
** 2. Permission is granted to anyone to use the SOFA software for any
|
|
** purpose, including commercial applications, free of charge and
|
|
** without payment of royalties, subject to the conditions and
|
|
** restrictions listed below.
|
|
**
|
|
** 3. You (the user) may copy and distribute SOFA source code to others,
|
|
** and use and adapt its code and algorithms in your own software,
|
|
** on a world-wide, royalty-free basis. That portion of your
|
|
** distribution that does not consist of intact and unchanged copies
|
|
** of SOFA source code files is a "derived work" that must comply
|
|
** with the following requirements:
|
|
**
|
|
** a) Your work shall be marked or carry a statement that it
|
|
** (i) uses routines and computations derived by you from
|
|
** software provided by SOFA under license to you; and
|
|
** (ii) does not itself constitute software provided by and/or
|
|
** endorsed by SOFA.
|
|
**
|
|
** b) The source code of your derived work must contain descriptions
|
|
** of how the derived work is based upon, contains and/or differs
|
|
** from the original SOFA software.
|
|
**
|
|
** c) The names of all routines in your derived work shall not
|
|
** include the prefix "iau" or "sofa" or trivial modifications
|
|
** thereof such as changes of case.
|
|
**
|
|
** d) The origin of the SOFA components of your derived work must
|
|
** not be misrepresented; you must not claim that you wrote the
|
|
** original software, nor file a patent application for SOFA
|
|
** software or algorithms embedded in the SOFA software.
|
|
**
|
|
** e) These requirements must be reproduced intact in any source
|
|
** distribution and shall apply to anyone to whom you have
|
|
** granted a further right to modify the source code of your
|
|
** derived work.
|
|
**
|
|
** Note that, as originally distributed, the SOFA software is
|
|
** intended to be a definitive implementation of the IAU standards,
|
|
** and consequently third-party modifications are discouraged. All
|
|
** variations, no matter how minor, must be explicitly marked as
|
|
** such, as explained above.
|
|
**
|
|
** 4. You shall not cause the SOFA software to be brought into
|
|
** disrepute, either by misuse, or use for inappropriate tasks, or
|
|
** by inappropriate modification.
|
|
**
|
|
** 5. The SOFA software is provided "as is" and SOFA makes no warranty
|
|
** as to its use or performance. SOFA does not and cannot warrant
|
|
** the performance or results which the user may obtain by using the
|
|
** SOFA software. SOFA makes no warranties, express or implied, as
|
|
** to non-infringement of third party rights, merchantability, or
|
|
** fitness for any particular purpose. In no event will SOFA be
|
|
** liable to the user for any consequential, incidental, or special
|
|
** damages, including any lost profits or lost savings, even if a
|
|
** SOFA representative has been advised of such damages, or for any
|
|
** claim by any third party.
|
|
**
|
|
** 6. The provision of any version of the SOFA software under the terms
|
|
** and conditions specified herein does not imply that future
|
|
** versions will also be made available under the same terms and
|
|
** conditions.
|
|
*
|
|
** In any published work or commercial product which uses the SOFA
|
|
** software directly, acknowledgement (see www.iausofa.org) is
|
|
** appreciated.
|
|
**
|
|
** Correspondence concerning SOFA software should be addressed as
|
|
** follows:
|
|
**
|
|
** By email: sofa@ukho.gov.uk
|
|
** By post: IAU SOFA Center
|
|
** HM Nautical Almanac Office
|
|
** UK Hydrographic Office
|
|
** Admiralty Way, Taunton
|
|
** Somerset, TA1 2DN
|
|
** United Kingdom
|
|
**
|
|
**--------------------------------------------------------------------*/
|
|
}
|