Enum Frame 

pub enum Frame {
    ITRF,
    TIRS,
    CIRS,
    GCRF,
    TEME,
    EME2000,
    ICRF,
    LVLH,
    RTN,
    NTW,
}

Reference frame identifier.

Used throughout satkit to tag vectors with the coordinate system in which they are expressed. For Earth-centred inertial and Earth-fixed frames the definitions follow the IERS conventions; for spacecraft-local orbital frames see the individual variant docs.

Variants

ITRF

International Terrestrial Reference Frame

TIRS

Terrestrial Intermediate Reference System

CIRS

Celestial Intermediate Reference System

GCRF

Geocentric Celestial Reference Frame

TEME

True Equator Mean Equinox

EME2000

Earth Mean Equator 2000

ICRF

International Celestial Reference Frame

LVLH

Local Vertical Local Horizontal

• z axis = -r (nadir)
• y axis = -h (opposite angular momentum, h = r × v)
• x axis completes the right-handed system (approximately velocity direction for circular orbits)

RTN

Radial / Tangential / Normal — CCSDS OEM/OMM/ODM convention.

Also known as RSW (Vallado’s Fundamentals of Astrodynamics) or RIC (Radial / In-track / Cross-track, older NASA usage and Clohessy-Wiltshire literature). The three names refer to the same axes; different communities use different letters. Compile- time aliases Frame::RSW and Frame::RIC are available so user code can spell the frame whichever way matches the source it’s transcribing from — all three resolve to the same enum variant.

• R (radial): unit vector along position, outward from Earth centre
• T (tangential / in-track): perpendicular to R in the orbit plane, in the prograde direction. Not parallel to the velocity vector unless the flight-path angle is zero (circular orbit, or perigee/apogee of an eccentric orbit). For eccentric orbits at non-apsidal true anomaly, use Frame::NTW if you want an axis parallel to velocity.
• N (normal / cross-track): along the angular momentum direction h = r × v, completing the right-handed system

This frame is the standard choice for CCSDS OEM / OMM / ODM orbit data messages (which label it RTN), for relative motion formulations (Hill / Clohessy-Wiltshire equations, often written in RIC), and for radial/normal burn components whose physical meaning is tied to the position vector. satkit’s state-vector uncertainty API accepts RTN as one of several frames — see SatState::set_pos_uncertainty.

NTW

Velocity-aligned orbital frame (Vallado §3.3).

• N (normal-to-velocity, in-plane): T̂ × Ŵ. For a circular orbit this is the outward radial direction; for an eccentric orbit it leans away from the radial by the flight-path angle.
• T (tangent): v̂, the unit velocity vector
• W (cross-track, out of plane): (r × v) / |r × v|, same as RIC’s C axis

This is the natural frame for thrust-along-velocity maneuvers: a pure +T delta-v of magnitude Δv adds exactly Δv to |v| and changes orbital energy by v · Δv. For eccentric orbits at non-apsidal true anomalies, NTW and RIC differ by the flight-path angle, so the choice matters. Use NTW when planning prograde/retrograde burns, Hohmann transfers, or anything else where “along velocity” is the physically meaningful direction. Use Frame::RTN when you want “perpendicular to position” semantics or when interoperating with CCSDS OEM / OMM covariance messages (which use this frame under the RTN name).

Implementations

impl Frame

pub const RSW: Self = Self::RTN

Compile-time alias for Frame::RTN — Vallado’s name for the same Radial / S=(W×R) / W=(R×V) orbital frame. Provided so code transcribing formulas from Vallado’s Fundamentals of Astrodynamics can use the source’s variable names verbatim. Semantically identical to Frame::RTN; Display always renders as RTN.

pub const RIC: Self = Self::RTN

Compile-time alias for Frame::RTN — the older NASA / Clohessy-Wiltshire literature name for the same axes (Radial / In-track / Cross-track). Provided for backward compatibility with code that was written against the previous canonical name in earlier satkit versions, and for readers of papers that use “RIC” rather than “RTN”. Semantically identical to Frame::RTN; Display always renders as RTN.

Trait Implementations

impl Clone for Frame

fn clone(&self) -> Frame

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for Frame

impl Debug for Frame

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for Frame

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Display for Frame

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Eq for Frame

impl FromStr for Frame

type Err = Error

The associated error which can be returned from parsing.

fn from_str(s: &str) -> Result<Self, Self::Err>

Parses a string s to return a value of this type.

impl PartialEq for Frame

fn eq(&self, other: &Frame) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Serialize for Frame

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for Frame