update ast 8.6.2

1 files changed, 168 insertions, 0 deletions

diff --git a/ast/erfa/taiutc.c b/ast/erfa/taiutc.c
new file mode 100644
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+++ b/ast/erfa/taiutc.c
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+#include "erfa.h"
+
+int eraTaiutc(double tai1, double tai2, double *utc1, double *utc2)
+/*
+**  - - - - - - - - - -
+**   e r a T a i u t c
+**  - - - - - - - - - -
+**
+**  Time scale transformation:  International Atomic Time, TAI, to
+**  Coordinated Universal Time, UTC.
+**
+**  Given:
+**     tai1,tai2  double   TAI as a 2-part Julian Date (Note 1)
+**
+**  Returned:
+**     utc1,utc2  double   UTC as a 2-part quasi Julian Date (Notes 1-3)
+**
+**  Returned (function value):
+**                int      status: +1 = dubious year (Note 4)
+**                                  0 = OK
+**                                 -1 = unacceptable date
+**
+**  Notes:
+**
+**  1) tai1+tai2 is Julian Date, apportioned in any convenient way
+**     between the two arguments, for example where tai1 is the Julian
+**     Day Number and tai2 is the fraction of a day.  The returned utc1
+**     and utc2 form an analogous pair, except that a special convention
+**     is used, to deal with the problem of leap seconds - see the next
+**     note.
+**
+**  2) JD cannot unambiguously represent UTC during a leap second unless
+**     special measures are taken.  The convention in the present
+**     function is that the JD day represents UTC days whether the
+**     length is 86399, 86400 or 86401 SI seconds.  In the 1960-1972 era
+**     there were smaller jumps (in either direction) each time the
+**     linear UTC(TAI) expression was changed, and these "mini-leaps"
+**     are also included in the ERFA convention.
+**
+**  3) The function eraD2dtf can be used to transform the UTC quasi-JD
+**     into calendar date and clock time, including UTC leap second
+**     handling.
+**
+**  4) The warning status "dubious year" flags UTCs that predate the
+**     introduction of the time scale or that are too far in the future
+**     to be trusted.  See eraDat for further details.
+**
+**  Called:
+**     eraUtctai    UTC to TAI
+**
+**  References:
+**
+**     McCarthy, D. D., Petit, G. (eds.), IERS Conventions (2003),
+**     IERS Technical Note No. 32, BKG (2004)
+**
+**     Explanatory Supplement to the Astronomical Almanac,
+**     P. Kenneth Seidelmann (ed), University Science Books (1992)
+**
+**  Copyright (C) 2013-2016, NumFOCUS Foundation.
+**  Derived, with permission, from the SOFA library.  See notes at end of file.
+*/
+{
+   int big1;
+   int i, j;
+   double a1, a2, u1, u2, g1, g2;
+
+
+/* Put the two parts of the TAI into big-first order. */
+   big1 = ( tai1 >= tai2 );
+   if ( big1 ) {
+      a1 = tai1;
+      a2 = tai2;
+   } else {
+      a1 = tai2;
+      a2 = tai1;
+   }
+
+/* Initial guess for UTC. */
+   u1 = a1;
+   u2 = a2;
+
+/* Iterate (though in most cases just once is enough). */
+   for ( i = 0; i < 3; i++ ) {
+
+   /* Guessed UTC to TAI. */
+      j = eraUtctai(u1, u2, &g1, &g2);
+      if ( j < 0 ) return j;
+
+   /* Adjust guessed UTC. */
+      u2 += a1 - g1;
+      u2 += a2 - g2;
+   }
+
+/* Return the UTC result, preserving the TAI order. */
+   if ( big1 ) {
+      *utc1 = u1;
+      *utc2 = u2;
+   } else {
+      *utc1 = u2;
+      *utc2 = u1;
+   }
+
+/* Status. */
+   return j;
+
+}
+/*----------------------------------------------------------------------
+**  
+**  
+**  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.
+**  
+*/