Function lupnt::GetEopData

• Defined in File eop.cc

Function Documentation

EopData lupnt::GetEopData(Real mjd_utc)

Interpolate Earth orientation parameters (polar motion, UT1-UTC, LOD, nutation corrections) to a requested epoch from the loaded IERS EOP table.

Called by frame-conversion routines such as RotPolarMotion, RotSideralMotion, and RotSideralMotionDot (see frame_conversions.cc) to obtain the EOP values needed for the GCRF<->ITRF rotation at a given epoch. Lazily loads the bundled EOP file via LoadEopFileData/GetFilePath(EOP_FILENAME) on first use. For epochs outside the table’s range, the nearest endpoint’s values are held constant (no extrapolation); otherwise a 3rd-order Lagrange interpolation is used.

Parameters:

mjd_utc – Epoch at which to evaluate the EOP [MJD, UTC]

Returns:

Interpolated EOP values (x_pole/y_pole [rad], ut1_utc [s], lod [s], dpsi/deps [rad], dx_pole/dy_pole [rad], tai_utc [s])