astroforge.coordinates.MEMEDToCIRS#

astroforge.coordinates.MEMEDToCIRS(time, X)[source]#

Converts a cartesian vector from the Mean Equator Mean Equinox of Date (MEMED) coordinate system to the Celestrial Intermediate Reference System (CIRS). CIRS is a geocentric coordinate system whose x-axis is in the direction of the Celestial Intermediate Origin (CIO) and whose z-axis is in the direction of the Celestial Intermediate Pole (CIP). See Kaplan (2005) for more information.

Parameters:
  • time (float) – Reference epoch for the MEMED coordinate system, specified as a Modified Julian Date (MJD) in the UT1 time system.

  • X (NDArray[np.float64]) – Shape (3,) vector to be rotated

Returns:

Rotated vector in the CIRS system

Return type:

NDArray[np.float64]