ut1utc¶
- erfa.ut1utc(ut11, ut12, dut1)[source]¶
Time scale transformation: Universal Time, UT1, to Coordinated Universal Time, UTC.
- Parameters:
- ut11double array
- ut12double array
- dut1double array
- Returns:
- utc1double array
- utc2double array
Notes
Wraps ERFA function
eraUt1utc
. The ERFA documentation is:- - - - - - - - - - e r a U t 1 u t c - - - - - - - - - - Time scale transformation: Universal Time, UT1, to Coordinated Universal Time, UTC. Given: ut11,ut12 double UT1 as a 2-part Julian Date (Note 1) dut1 double Delta UT1: UT1-UTC in seconds (Note 2) Returned: utc1,utc2 double UTC as a 2-part quasi Julian Date (Notes 3,4) Returned (function value): int status: +1 = dubious year (Note 5) 0 = OK -1 = unacceptable date Notes: 1) ut11+ut12 is Julian Date, apportioned in any convenient way between the two arguments, for example where ut11 is the Julian Day Number and ut12 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 Note 3. 2) Delta UT1 can be obtained from tabulations provided by the International Earth Rotation and Reference Systems Service. The value changes abruptly by 1s at a leap second; however, close to a leap second the algorithm used here is tolerant of the "wrong" choice of value being made. 3) JD cannot unambiguously represent UTC during a leap second unless special measures are taken. The convention in the present function is that the returned quasi-JD UTC1+UTC2 represents UTC days whether the length is 86399, 86400 or 86401 SI seconds. 4) The function eraD2dtf can be used to transform the UTC quasi-JD into calendar date and clock time, including UTC leap second handling. 5) 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: eraJd2cal JD to Gregorian calendar eraDat delta(AT) = TAI-UTC eraCal2jd Gregorian calendar to JD 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) This revision: 2023 May 6 Copyright (C) 2013-2023, NumFOCUS Foundation. Derived, with permission, from the SOFA library. See notes at end of file.