arika

Traits

Name	Description
Ut1Offset	Provides the UT1 − UTC (dUT1) offset.
PolarMotion	Provides the polar motion components x_pole, y_pole.
NutationCorrections	Provides the IAU 2000A nutation corrections dX, dY.
LengthOfDay	Provides the Length of Day (LOD) parameter.
FullEopProvider	Convenience alias for a provider that supplies every EOP parameter.
AngleUnit	Marker trait for an angular unit.
TimeScale	A time scale marker.
Frame	Top-level frame trait.
Eci	Structural category for earth-centered inertial frames.
Ecef	Structural category for earth-centered earth-fixed frames.
LocalOrbital	Structural category for local orbital frames.
MoonEphemeris	Moon ephemeris source abstraction.

Structs

Name	Description
BodyProperties	Physical properties of a celestial body.
EopEntry	A single EOP data point at a specific MJD.
Finals2000A	Parser for IERS finals2000A.all / finals2000A.data / finals2000A.daily.
EopTable	Interpolated EOP lookup table.
NullEop	EOP placeholder that implements none of the EOP parameter traits.
Geodetic	Geodetic coordinates (WGS-84).
CipCoordinates	All three CIP / CIO quantities evaluated at a single t.
FundamentalArguments	All fundamental arguments evaluated at a single t value, as
FukushimaWilliamsAngles	The Fukushima-Williams angles at a given t, all as [Rad].
EclipticPrecessionAngles	The classical Lieske-style precession angles at a given t, all as
Radians	Radian angular unit (the canonical internal form).
Arcseconds	Arcsecond angular unit: 1 arcsec = π / 648_000 rad.
Milliarcseconds	Milliarcsecond angular unit: 1 mas = 1e-3 arcsec.
Microarcseconds	Microarcsecond angular unit: 1 µas = 1e-6 arcsec.
Angle	A scalar angle tagged with its unit U.
Utc	Coordinated Universal Time.
Tai	International Atomic Time.
Tt	Terrestrial Time.
Ut1	Universal Time (UT1).
Tdb	Barycentric Dynamical Time.
DateTime	A Gregorian calendar date and time (UTC).
Epoch	An astronomical epoch represented as Julian Date in scale S.
Duration	Scale-invariant duration measured in SI (TAI) seconds.
SimpleEci	Approximate Earth-centered inertial frame: the “parent frame” for the
SimpleEcef	Approximate Earth-centered Earth-fixed frame: the result of applying an
Gcrs	Geocentric Celestial Reference System.
Cirs	Celestial Intermediate Reference System.
Tirs	Terrestrial Intermediate Reference System.
Itrs	International Terrestrial Reference System.
Rsw	Local orbital frame: Radial / Along-track / Cross-track.
Body	Spacecraft body-fixed frame.
Vec3	Frame-tagged 3D vector.
Rotation	座標系 From から To への回転。
HorizonsSample	One state-vector sample from a Horizons vector table.
HorizonsTable	A parsed Horizons vector table with Hermite interpolation support.
HorizonsMoonEphemeris	Moon ephemeris backed by a tabulated JPL Horizons vector table with
MeeusMoonEphemeris	Meeus analytical Moon ephemeris (Chapter 47 of “Astronomical Algorithms”).
IauRotationModel	IAU rotation model parameters for a celestial body.

Enums

Name	Description
KnownBody	Known celestial bodies with pre-defined physical properties.
ObjectCategory	Category of a simulation object.
EopParseError	Error during EOP data file parsing.
EopLookupError	Error during EOP table lookup.
FrameCategory	Category tag for runtime frame identification.
FrameDescriptor	Concrete frame identifier for runtime identification and serialization.
HorizonsError	Errors produced by the Horizons parser / fetcher.

Functions

Name	Description
geodetic_altitude	Compute WGS-84 geodetic altitude [km] directly from a position vector [km].
cip_xy	Evaluate the CIP (X, Y) coordinates at TT Julian centuries t.
cio_locator_s	Evaluate the CIO locator s(t) at TT Julian centuries t, given
cip_coordinates	Evaluate X, Y, and s at TT Julian centuries t in a single
gcrs_to_cirs_matrix	Assemble the 3×3 celestial-to-intermediate rotation matrix C
gcrs_to_cirs_matrix_at	Assemble the GCRS→CIRS matrix directly from TT Julian centuries t.
fa_l	F1 = l, mean anomaly of the Moon.
fa_l_prime	F2 = l', mean anomaly of the Sun.
fa_f	F3 = F = L − Ω, mean argument of latitude of the Moon.
fa_d	F4 = D, mean elongation of the Moon from the Sun.
fa_omega	F5 = Ω, mean longitude of the Moon’s ascending node.
fa_l_me	F6 = L_Me, mean longitude of Mercury.
fa_l_ve	F7 = L_Ve, mean longitude of Venus.
fa_l_e	F8 = L_E, mean longitude of Earth.
fa_l_ma	F9 = L_Ma, mean longitude of Mars.
fa_l_j	F10 = L_J, mean longitude of Jupiter.
fa_l_sa	F11 = L_Sa, mean longitude of Saturn.
fa_l_u	F12 = L_U, mean longitude of Uranus.
fa_l_ne	F13 = L_Ne, mean longitude of Neptune.
fa_p_a	F14 = p_A, general precession in longitude.
fukushima_williams	Evaluate the Fukushima-Williams precession angles at TT Julian
ecliptic_precession_angles	Evaluate the Lieske ecliptic-and-equator precession angles at TT
moon_position_eci	Moon position vector in ECI (J2000) frame [km].
moon_orientation	Moon body-fixed → ECI orientation with IAU 2009 libration corrections.
obliquity	Mean obliquity of the ecliptic at epoch [radians].
ecliptic_to_equatorial	Rotate a vector from ecliptic to J2000 equatorial frame.
heliocentric_position_ecliptic	Compute heliocentric position of a planet in the ecliptic frame [km].
model_for_body	Look up the base IAU rotation model for a body by name.
body_orientation	Compute the body-fixed → ECI orientation for a named body.
equation_of_time	Equation of Time [hours].
sun_direction_eci	Approximate sun direction (unit vector) in ECI (J2000) frame.
sun_direction_from_body	Sun direction (unit vector) as seen from a given central body, in J2000 equatorial frame.
sun_distance_from_body	Sun distance [km] from a given central body.
sun_distance_km	Sun-Earth distance [km] at the given epoch.
sun_position_eci	Sun position vector in ECI (J2000) frame [km].
rsw_quaternion	Compute the RSW (Radial / Along-track / Cross-track) orbital frame
body_quat_to_rsw	Transform a body-to-ECI quaternion into a body-to-RSW quaternion.

Type Aliases

Name	Description
Rad	Type alias for an angle in radians.
Arcsec	Type alias for an angle in arcseconds.
Mas	Type alias for an angle in milliarcseconds.
Uas	Type alias for an angle in microarcseconds.
SimpleEci	Approximate Earth-centered inertial frame vector.
SimpleEcef	Approximate Earth-centered Earth-fixed frame vector.
Gcrs	Geocentric Celestial Reference System frame vector.
Rsw	Local orbital frame vector (Radial / Along-track / Cross-track).

Constants

Name	Description
WGS84_A	WGS-84 semi-major axis [km].
WGS84_F	WGS-84 flattening.
WGS84_B	WGS-84 semi-minor axis [km].
WGS84_E2	WGS-84 first eccentricity squared.
EPSILON_0	Mean obliquity of the ecliptic at J2000.0 (ε₀).
DAS2R	Arcseconds → radians.
DMAS2R	Milliarcseconds → radians.
DUAS2R	Microarcseconds → radians.
TURNAS	Arcseconds in a full turn.
EARTH	IAU 2009 rotation model for the Earth.
MU	Earth gravitational parameter [km³/s²] (WGS-84).
R	Earth equatorial radius [km] (WGS-84).
J2	Earth J2 zonal harmonic coefficient (WGS-84 / EGM96).
J3	Earth J3 zonal harmonic coefficient (WGS-84 / EGM96).
J4	Earth J4 zonal harmonic coefficient (WGS-84 / EGM96).
OMEGA	Earth rotation rate [rad/s] (IERS 2010).
J2000_JD	Julian Date of J2000.0 epoch (JD 2451545.0).
MOON	IAU 2009 rotation model for the Moon (base linear terms).
MU	Moon gravitational parameter [km³/s²].
MARS	IAU 2009 rotation model for Mars.
SUN	IAU 2009 rotation model for the Sun.
MU	Sun gravitational parameter [km³/s²].
AU_KM	One astronomical unit in kilometres.