Ut1Epoch
Defined in: convert.rs:311
pub struct Ut1EpochAn epoch on the UT1 (Earth-rotation) time scale, stored as a UT1 Julian Date.
Separate from Epoch because UT1 is realized by Earth’s rotation, not
atomic clocks: reaching it requires a measured dUT1 (see
Epoch::<Utc>::to_ut1). Carries the definitional Earth Rotation Angle.
Methods
Section titled “Methods”from_jd_ut1()
Section titled “from_jd_ut1()”fn from_jd_ut1(jd: f64) -> Self
Create a UT1 epoch from a Julian Date value interpreted as UT1 JD.
fn jd(&self) -> f64
The UT1 Julian Date.
fn era(&self) -> f64
Earth Rotation Angle (ERA) in radians.
IAU 2000 Resolution B1.8 / SOFA iauEra00:
ERA(T_u) = 2π × (0.7790572732640 + 1.00273781191135448 × T_u)
where T_u = JD_UT1 − 2451545.0.
ERA は UT1 の definitional な関数。Ut1Epoch にのみ提供される。