diff options
author | William Joye <wjoye@cfa.harvard.edu> | 2019-05-10 15:55:01 (GMT) |
---|---|---|
committer | William Joye <wjoye@cfa.harvard.edu> | 2019-05-10 15:55:01 (GMT) |
commit | 9646e8d50bc1481de77459d59738826f9c256ad6 (patch) | |
tree | e47684c08ae346d96e3c6ea8780f3886fe74e6f6 /ast/erfa/gmst82.c | |
parent | 37e757832a7f2c690cea41df5bf9cfa9ee18f67f (diff) | |
download | blt-9646e8d50bc1481de77459d59738826f9c256ad6.zip blt-9646e8d50bc1481de77459d59738826f9c256ad6.tar.gz blt-9646e8d50bc1481de77459d59738826f9c256ad6.tar.bz2 |
upgrade ast 8.7.1
Diffstat (limited to 'ast/erfa/gmst82.c')
-rw-r--r-- | ast/erfa/gmst82.c | 160 |
1 files changed, 0 insertions, 160 deletions
diff --git a/ast/erfa/gmst82.c b/ast/erfa/gmst82.c deleted file mode 100644 index 9484b66..0000000 --- a/ast/erfa/gmst82.c +++ /dev/null @@ -1,160 +0,0 @@ -#include "erfa.h" - -double eraGmst82(double dj1, double dj2) -/* -** - - - - - - - - - - -** e r a G m s t 8 2 -** - - - - - - - - - - -** -** Universal Time to Greenwich mean sidereal time (IAU 1982 model). -** -** Given: -** dj1,dj2 double UT1 Julian Date (see note) -** -** Returned (function value): -** double Greenwich mean sidereal time (radians) -** -** Notes: -** -** 1) The UT1 date dj1+dj2 is a Julian Date, apportioned in any -** convenient way between the arguments dj1 and dj2. For example, -** JD(UT1)=2450123.7 could be expressed in any of these ways, -** among others: -** -** dj1 dj2 -** -** 2450123.7 0 (JD method) -** 2451545 -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 accuracy (or, at -** least, minimum noise) is delivered when the dj1 argument is for -** 0hrs UT1 on the day in question and the dj2 argument lies in the -** range 0 to 1, or vice versa. -** -** 2) The algorithm is based on the IAU 1982 expression. This is -** always described as giving the GMST at 0 hours UT1. In fact, it -** gives the difference between the GMST and the UT, the steady -** 4-minutes-per-day drawing-ahead of ST with respect to UT. When -** whole days are ignored, the expression happens to equal the GMST -** at 0 hours UT1 each day. -** -** 3) In this function, the entire UT1 (the sum of the two arguments -** dj1 and dj2) is used directly as the argument for the standard -** formula, the constant term of which is adjusted by 12 hours to -** take account of the noon phasing of Julian Date. The UT1 is then -** added, but omitting whole days to conserve accuracy. -** -** Called: -** eraAnp normalize angle into range 0 to 2pi -** -** References: -** -** Transactions of the International Astronomical Union, -** XVIII B, 67 (1983). -** -** Aoki et al., Astron. Astrophys. 105, 359-361 (1982). -** -** Copyright (C) 2013-2016, NumFOCUS Foundation. -** Derived, with permission, from the SOFA library. See notes at end of file. -*/ -{ -/* Coefficients of IAU 1982 GMST-UT1 model */ - double A = 24110.54841 - ERFA_DAYSEC / 2.0; - double B = 8640184.812866; - double C = 0.093104; - double D = -6.2e-6; - -/* Note: the first constant, A, has to be adjusted by 12 hours */ -/* because the UT1 is supplied as a Julian date, which begins */ -/* at noon. */ - - double d1, d2, t, f, gmst; - - -/* Julian centuries since fundamental epoch. */ - if (dj1 < dj2) { - d1 = dj1; - d2 = dj2; - } else { - d1 = dj2; - d2 = dj1; - } - t = (d1 + (d2 - ERFA_DJ00)) / ERFA_DJC; - -/* Fractional part of JD(UT1), in seconds. */ - f = ERFA_DAYSEC * (fmod(d1, 1.0) + fmod(d2, 1.0)); - -/* GMST at this UT1. */ - gmst = eraAnp(ERFA_DS2R * ((A + (B + (C + D * t) * t) * t) + f)); - - return gmst; - -} -/*---------------------------------------------------------------------- -** -** -** 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. -** -*/ |