Updates for SOFA Release 17 : 2021 January 25 - - - - - - - - - - - - - - - - - - - - - - - Summary of Changes ------------------ The changes fall into the following categories: (1) Extra defensive precautions when computing atmospheric refraction at low altitudes. (2) Application of polar motion handling changed to rigorous. These improvements may result in differences which will be less than 1 mu arcsecond (0.000 001 arc seconds). (3) Expanded documentation, including a new cookbook for the SOFA Vector Matrix Library. (4) Typographical and other minor corrections. (5) Changes to the test program. + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + FORTRAN 77 Library ------------------ (1) iau_ATIOQ Include a limit in altitude (about 3 degrees) below which atmospheric refraction is held constant, for defense and to make it consistent with iau_atoiq. (2) iau_ATIOQ Application of polar motion calculation iau_ATOIQ made rigorous for canonical consistency. iau_APCO iau_APIO (3) The updates in the following routines were documentation corrections/additions: iau_EE00B IERS Conventions reference updated to (2003) iau_GST00B IERS Conventions reference updated to (2003) iau_PMAT06 IAU reference added iau_PNM06A Variable renamed to follow SOFA nomenclature iau_PNM80 Date variables now correctly labelled as TT iau_TRXPV Action corrected to R^T * PV together with additional note (4) The updates in the following routines are documentation improvements and typographical corrections: iau_AF2A iau_BI00 iau_C2I00A iau_C2T00A iau_C2T00B iau_C2T06A iau_C2TPE iau_C2TXY iau_CAL2JD iau_EO06A iau_EORS iau_EPB2JD iau_EPJ2JD iau_FAOM03 iau_FW2M iau_GMST00 iau_GMST06 iau_GST00A iau_GST06 iau_GST06A iau_GST94 iau_JD2CAL iau_JDCALF iau_NUM00A iau_PMAT00 iau_PNM00A iau_PNM00B iau_POM00 iau_PVU iau_REFCO iau_RV2M iau_RXPV iau_TCGTT iau_TF2A iau_UT1UTC iau_XYS00B iau_XYS06A iau_ZP iau_ZPV (5) Test program t_sofa_f.f was updated due to items (1) and (2) above. + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ANSI C Library -------------- (1) iauAtoiq Include a limit in altitude (about 3 degrees) below which atmospheric refraction is held constant, for defense and to make it consistent with iauAtioq. (2) iauAtioq Application of polar motion calculation made rigorous iauAtoiq for canonical consistency. iauApco iauApio (3) The updates in the following functions were documentation corrections: iauEe00b IERS Conventions reference updated to (2003) iaugst00b IERS Conventions reference updated to (2003) iauPmat06 IAU reference added iauPnm06a Variable renamed to follow SOFA nomenclature iauTrxpv Action corrected to R^T * PV together with additional note (4) The updates in the following functions are documentation improvements and typographical corrections: iauAtciqn iauAticqn iauBi00 iauC2i00a iauC2t00a iauC2t00b iauC2t06a iauC2tpe iauC2txy iauEo06a iauEors iauFaom03 iauFk45z iauFk54z iauFw2m iauGmst00 iauGst00a iauGst06 iauGst06a iauGst94 iauJd2cal iauJdcalf iauNum00a iauPmat00 iauPn00a iauPn00b iauPn06 iauPnm00a iauPnm00b iauPnm80 iauPom00 iauRefco iauRv2m iauRxpv iauS00 iauSxpv iautcgtt iauUt1utc iauXys00b iauXys06a iauZp iauZpv (5) Test program t_sofa_c.c was updated due to items (1) and (2) above. + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + SOFA thanks all those who have reported the various issues that go + to ensuring the libraries and documentation are kept up-to-date and + relevant. + + End of updates + 2021 January 08 + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + Updates for SOFA Release 17a : 2021 February - - - - - - - - - - - - - - - - - - - - - - - Summary of Change ----------------- The change for this minor release (17a) relates to dealing with leap seconds during the period 1960 and 1971. Between the introduction of UTC at the start of 1960 and the first leap second at the end of 1971 there were a series of small offsets and rate changes with respect to TAI. The SOFA routine D2DTF takes these into account, but a shortcoming in the algorithm meant that under certain conditions a leap second could be flagged even though none had occurred. Such cases were extremely rare, and moreover depended to some extent on compiler behaviour, affecting rounding. SOFA is grateful to the Astropy group for reporting an instance of this bug, which has been corrected. FORTRAN Routine ---------------- iau_d2dtf Format for output a 2-part Julian Date (or in the case of UTC a quasi-JD form that includes special provision for leap seconds). ANSI C: ------- iauD2dtf Format for output a 2-part Julian Date (or in the case of UTC a quasi-JD form that includes special provision for leap seconds). + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + End of Updates 2021 February 14 + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +