astroforge.coordinates.TIRSToITRS#

astroforge.coordinates.TIRSToITRS(mjd, X)[source]#

Rotate a cartesian vector from the Terrestrial Intermediate Reference System (TIRS) to the International Terrestrial Reference System (TIRS). TIRS and ITRS only differ by the polar motion.

Parameters:
  • mjd (float) – Time at which to evaluate the polar motion, expressed as a Modified Julian Date (MJD) in the UT1 time system.

  • X (NDArray[np.float64]) – Vector to be rotated, should have shape (3, )

Returns:

Y – Rotated vector

Return type:

NDArray[np.float64]