astroforge.force_models.F_geo_MEMED#

astroforge.force_models.F_geo_MEMED(time, z)[source]#

Compute Earth’s gravitational potential for a position in ITRS coordinates using an 8x8 spherical harmonics model. This functon is a wrapper around F_geo_ITRS. It converts the position vector from MEMED to ITRS, computes the acceleration, and then converts the acceleration vector back to MEMED.

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

  • z (NDArray[np.float64]) – Position vector at which the Earth’s gravitational potential will be evaluated. Should have shape (3, ) and be expressed in units of km in the MEMED coordinate system.

Returns:

acc – Acceleration vector due to Earth’s gravity. The output has shape (3, ) and is in units of km / s2.

Return type:

NDArray[np.float64]