Theses 3 services below display data on a webpage and you can retrieve these datas in your
script or program with the command "curl". You will need this command installed on your computer
Traditionnal webservice has been abandonned.
1- Leap second
This page gives the current value of UT1-UTC, the date of the last leap second and the date of the next leap second.
If no leap second is scheduled, then it ouputs "Not scheduled".
This page relies on the information of the last Bulletin C and the current date.
Transformation coordinate M from the international terrestrial reference system
(ITRF) to the international celestial reference frame (ICRF) :
Celestial coordinates ( X Y Z) = M x Terrestrial coordinates ( x y z )
We use the FORTRAN CODE of the VLBI analysis Software GLORIA developped by
Anne-Marie Gontier (Paris Observatory), and compatible with the IAU 2000 resolutions
from 1962 to the current week the matrix can include the whole EOP set of
the IERS combined series C04 (daily step, 0hUTC, time resolution for such
EOP fluctuations is about 6 days), as well as diurnal and semi-diurnal effects
produced by ocean tides, which amount about 0.001". Accuracy is 0.0001",
corresponding to 5 10-10 rad. In turn the time resolution of the
matrix can reach approximatively 6 hours. Bewteen two dates at 0hUTC the EOP
are interpolated according to a cubic spline.
from the current week to 6 months after the matrix is computed from the prediction
of the polar motion and UT1-UTC.
outside the range [1962, current week+ 6 months prediction] the rotation matrix
is restricted to the diurnal rotation and the precession-nutation model IAU
The last digit (12) of the matrix element corresponds to the pico radian level.
Corresponding time resolution for the matrix variation is 14 nano seconds.
Components of the instantaneous rotation vector are deduced from the orientation
matrix and its time derivative.