Updates for SOFA Release 13 : 2017 April 20
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Summary of Changes
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The changes fall into the following categories:
1. Implementation of the IAU 2012 definition of the astronomical
unit (au). Not only has this constant been updated, but also
(a) all derived quantities are evaluated via the appropriate
formulas, and
(b) all documentation now uses the appropriate symbols for the
unit, for example, 1 au and 2.3 au/day.
2. Update to PVSTAR to make it consistent with the version of STARPV
that was updated in the previous release.
3. Other minor typographical corrections to various routines.
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FORTRAN Library
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1. iau_APCS The IAU 2012 value of the astronomical unit (au) is
iau_LDN now implemented in these six routines.
iau_PMPX
iau_PVSTAR
iau_STARPM
iau_STARPV
2. iau_PVSTAR An expression (sqrt(1-x)-1), where x is usually tiny,
has been replaced with (-x/(sqrt(1-x)+1) to improve
numerical precision.
3. t_sofa_f Check values in this validation program updated due
to the change in the astronomical unit.
4. sofa_ast_f The SOFA Astrometry Tools cookbook.
(a) In the table on page 22 there is a change of
+1 x 10^-7 seconds in RA for three results when
compared to using the previous value for the au.
These cases are repeated on the next 2 pages.
(b) The listing of the relativistic version of the
routine iau_PMPX in the Appendix has been updated
on page 77 with the required changes for the au.
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ANSI C Library
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1. sofam.h The astronomical unit (au) has been updated in this
include file and all constants that are derived from
the au have been replaced by the appropriate formulas.
2. iauPvstar An expression (sqrt(1-x)-1), where x is usually tiny,
has been replaced with (-x/(sqrt(1-x)+1) to improve
numerical precision.
3. t_sofa_c Check values in this validation program updated due
to the change in the astronomical unit.
4. sofa_ast_c The SOFA Astrometry Tools cookbook. In the table on
page 20 there is a change of +1 x 10^-7 seconds in RA
for three results when compared to using the previous
value for the au. These cases are repeated on the
next three pages.
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End of Updates
2017 March 22
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