tdbtt¶
-
erfa.
tdbtt
(tdb1, tdb2, dtr)[source]¶ Wrapper for ERFA function
eraTdbtt
.- Parameters
tdb1 : double array
tdb2 : double array
dtr : double array
- Returns
tt1 : double array
tt2 : double array
Notes
The ERFA documentation is below.
- - - - - - - - - e r a T d b t t - - - - - - - - - Time scale transformation: Barycentric Dynamical Time, TDB, to Terrestrial Time, TT. Given: tdb1,tdb2 double TDB as a 2-part Julian Date dtr double TDB-TT in seconds Returned: tt1,tt2 double TT as a 2-part Julian Date Returned (function value): int status: 0 = OK Notes: 1) tdb1+tdb2 is Julian Date, apportioned in any convenient way between the two arguments, for example where tdb1 is the Julian Day Number and tdb2 is the fraction of a day. The returned tt1,tt2 follow suit. 2) The argument dtr represents the quasi-periodic component of the GR transformation between TT and TCB. It is dependent upon the adopted solar-system ephemeris, and can be obtained by numerical integration, by interrogating a precomputed time ephemeris or by evaluating a model such as that implemented in the ERFA function eraDtdb. The quantity is dominated by an annual term of 1.7 ms amplitude. 3) TDB is essentially the same as Teph, the time argument for the JPL solar system ephemerides. References: McCarthy, D. D., Petit, G. (eds.), IERS Conventions (2003), IERS Technical Note No. 32, BKG (2004) IAU 2006 Resolution 3 Copyright (C) 2013-2019, NumFOCUS Foundation. Derived, with permission, from the SOFA library. See notes at end of file.