moon_position_eci

Defined in: ephemeris.rs:24

fn moon_position_eci(epoch: &Epoch) -> [Vec3<frame::Gcrs>](../../structs/vec3/)

Moon position vector in ECI (J2000) frame [km].

Uses the analytical model from Meeus “Astronomical Algorithms” Chapter 47 with full periodic term tables (60 terms for longitude/distance, 60 for latitude), E correction factor, and planetary perturbation corrections.

Accuracy: ~10” in ecliptic longitude, ~1% in distance (~4,000 km).

Time scale

Meeus ephemerides take a dynamical time argument (TDB). The public signature accepts &Epoch<Utc> (the default alias) for backward compatibility; the UTC epoch is converted to TDB internally via leap seconds + TT offset + Fairhead-Bretagnon periodic correction.