ephemeris meridian

ephemeris meridian

The fictitious terrestrial meridian that rotates independently of Earth at the uniform rate defined by terrestrial dynamical time. It is
1.002 738 δT

east of the Greenwich meridian (see delta T). Ephemeris longitude and ephemeris hour angle are measured relative to the ephemeris meridian.

References in periodicals archive ?
The orientation of the z-axis with respect to the ephemeris meridian of the rotating Earth is the ephemeris hour angle [micro].
Van Stockum thus referenced the longitude of Paramaribo with respect to the Ephemeris meridian instead of with respect to the Greenwich meridian.