Software Archive

The IAU SOFA Center makes a release of the SOFA product at intervals. Each release is termed an Issue and is identified by the date on which it was made available. Past issues of the SOFA product are available from this page.

  The SOFA Libraries

	Issue 2001-03-31.		This was the first release for Fortran 77.
	Issue 2003-04-29.		This was the second release for Fortran 77. A large number of new routines were added, supporting the IAU 2000 resolutions.
	Issue 2005-09-01.		This was the third release for Fortran 77. A number of small changes were introduced.
	Issue 2007-08-10.		This was the fourth release for Fortran 77, revised on 2007-08-28. A cookbook and a number of additional routines supporting the IAU 2006 precession model were added.
	Issue 2008-03-01.		This was the fifth release for Fortran 77. A number of small changes were introduced.
	Issue 2009-02-01.		This was the sixth release for Fortran 77 and the first release for ANSI C, revised on 2009-04-02. An ANSI C version of the SOFA library was introduced and small changes were introduced for both distributions.
	Issue 2009-12-31.		This was the seventh release for Fortran 77 and the second release for ANSI C, revised on 2010-01-27. Several Geocentric/Geodetic transformations were added to both libraries and some small changes were introduced for both distributions.
	Issue 2010-12-01.		This was the eighth release for Fortran 77 and the third release for ANSI C. Eighteen new routines were added to the Time Scales section of the Astronomy Library and some small changes and corrections were introduced for both distributions.
	Issue 2012-03-01.		This was the unified ninth release for Fortran 77 and ANSI C, revised on 2012-07-10. Some small changes and corrections were introduced for both distributions.
	Issue 2013-12-02.		This was the unified tenth release for Fortran 77 and ANSI C, revised on 2014-10-07. This includes the release of the Astrometry section containing 32 new routines and some small changes and corrections for both distributions.
	Issue 2015-02-09.		The unified eleventh release for Fortran 77 and ANSI C, revised on 2015-04-02. This includes a new section "Galactic Coordinates" consisting of 2 routines for transforming between ICRS and 1958 IAU galactic coordinates as well as one small correction for both distributions.
	Issue 2016-05-03.		The unified twelfth release for Fortran 77 and ANSI C, revised on 2016-12-23. This includes four new routines in the Precession/Nutation/Polar motion section delivering long-term precession and a new section "Ecliptic Coordinates" consisting of 6 routines for transforming between equatorial and ecliptic coordinates using either the IAU 2006 precession model or the long-term precession model of Vondrak et al. Separate Earth Attitude Cookbooks for Fortran and C users are provided as well as some small documentation corrections for both distributions.
	Issue 2017-04-20.		The unified thirteenth release for Fortran 77 and ANSI C. This release implements the IAU 2012 value of the astronomical unit, replacing the IAU 1976 value used up to now. Although this version inevitably changes returned values, it will only be at the microarcsecond level. Also, the routine PVSTAR has been changed to harmonize with algorithmic improvements made to STARPV in the previous release, eliminating discrepancies seen in round-trip test cases. Small documentation corrections have also been made and all changes have been summarized in the changes file for both distributions.
	Issue 2018-01-30.		The unified fourteenth release for Fortran 77 and ANSI C. This release implements two new sections entitled Horizon/Equatorial Coordinates and Gnomonic (tangent plane) Projections. Three routines have been added to the former covering transformations from azimuth and altitude to hour angle and declination and vice versa and the determination of the parallactic angle. Six routines have been added to the latter covering the determination of the tangent point and transformations of the position of the star to and from celestial and tangent plane coordinates. The Astrometry Tools Cookbook, the test programs and other supporting files have also been updated. Other minor documentation and typographical corrections have also been made. Changes are summarised in the changes file.
	Issue 2019-07-22.		The unified fifteenth release for Fortran 77 and ANSI C. This release implements four new routines in the Star Catalog Conversions section, corrects an incorrect sign in the ANSI C function iauTdbtcb and updates the DAT routines to the release year. Seventeen routines that compare the two components of given date/time arguments to minimize rounding errors, have been enhanced so that optimum results are achieved even when one of the arguments is negative Due to the introduction of the new routines, the Astrometry Tools Cookbook, the test program and other supporting files have been updated. Miscellaneous typographical corrections and improvements to various other documents have been made. Changes are summarised in the changes file.
	Issue 2020-07-21.		The unified sixteenth release for Fortran 77 and ANSI C. This release implements a correction of a sign in routine P06E and a correction in the ANSI C macro function dnint in the include file sofam.h to improve rounding. Improvements have also been made in precision and rounding in routines JD2CAL and JDCALF and in the method of decomposing the rotation matrix by ensuring that angles near zero are preferred in PB06. Miscellaneous typographical corrections and improvements to various other documents have been made. Changes are summarised in the changes file.
	Issue 2021-01-25.		The unified seventeenth release for Fortran 77 and ANSI C. This release implements extra defensive precautions when computing atmospheric refraction at low altitudes and the application of polar motion handling has been changed to rigorous. Documentation has been expanded including a new cookbook for the SOFA Vector Matrix Library and typographical and other minor corrections have also been applied. Changes have been made to the test programs. Minor release 17a corrects a shortcoming with D2DTF and its handling of leap seconds in the interval 1960 to 1971. Changes are summarised in the changes file.
	Issue 2021-05-12.		The unified eighteenth release for Fortran 77 and ANSI C. This major release implements three new support routines. Two deal with calculating astrometric places, while the third provides the approximate lunar position and velocity. The validation program has also been updated. A rearrangement of the ANSI C header files sofam.h and sofa.h has been implemented. The consequence of this is that an explicit #include "sofam.h" has been added to many of the SOFA functions. Thus developers of applications that use constants from sofa.h will now need to include an explicit #include. Further explanation is given in the changes.pdf files included in the distributions. The year of validity for the leap second (dat) routine has been extended and typographical and other minor corrections have been made to the documentation. Cosmetic changes have also been made to a number of ANSI C routines. Changes are summarised in the changes file.
	Issue 2023-10-11.		The unified nineteenth release for Fortran 77 and ANSI C. This major release implements corrections to two routines, STARPV and PVSTAR, updated parameters to the routine DAT as well as updated comments to several other routines and the ANSI C test program. Cosmetic changes have also been made to a number of other routines in both distributions. Forty SOFA routines are not mentioned in the existing cookbooks; in some cases simply because the routine was developed after the relevant cookbook had been written. To address this deficiency, enhancements have been drafted to two of the existing cookbooks (those on astrometry and Earth attitude) and a new one (on miscellaneous topics) has been written. This new cookbook is available for each distribution i.e. sofa_misc_f.pdf for Fortran 77 and sofa_misc_c.pdf for ANSI C. Topics include ecliptic and galactic coordinates, Hipparcos/FK5 and FK4/FK5 transformations, geodesy and solar-system ephemerides. This release can be found by following the Current Software link. Changes are summarised in the changes file.