Crate astrodyn_planet

Expand description

Planetary shape and standard preset bodies.

Pure-Rust port of JEOD’s models/environment/planet/ — the per-body reference-ellipsoid parameters (gravitational parameter, equatorial and polar radii, flattening) consumed by gravity, geodetic, atmospheric, and frame-rotation code.

§Public surface

PlanetShape (re-exported from planet) — the JEOD Planet struct equivalent. Stores name, mu (m^3/s^2), r_eq (m), r_pol (m), and flat_coeff along with derived helpers (flat_inv, e_ellipsoid).
presets — canonical body constants matching JEOD source data files. Earth uses WGS84 geometry from planet/data/src/earth.cc together with the GGM05C gravitational parameter mu = 398_600.441_50e9 m^3/s^2 (which differs from IERS 2010 by 3e6 m^3/s^2; we follow JEOD’s value to keep cross-validation faithful). Additional presets cover the other bodies the JEOD verification sims exercise.

§Role in the pipeline

PlanetShape is the shared parameter block consumed by astrodyn_math::geodetic for ellipsoidal coordinate conversions, by astrodyn_gravity when the gravity model needs the reference radius, and by astrodyn_frames for body-fixed rotation models. Pure Rust, zero Bevy dependency.

§Example

use astrodyn_planet::{EARTH, MOON};

// WGS84 equatorial radius, GGM05C gravitational parameter.
assert!((EARTH.r_eq - 6_378_137.0).abs() < 1.0);
assert!((EARTH.mu - 3.986_004_415e14).abs() < 1e6);

// Moon is much smaller and lighter than Earth.
assert!(MOON.r_eq < EARTH.r_eq);
assert!(MOON.mu < EARTH.mu);

Re-exports§

pub use planet::*;
pub use presets::*;

Modules§

geodetic_verif: JEOD PlanetFixedPosition verification seeds (committed JSON).
planet: Reference-ellipsoid parameter block for a planetary body.
presets: Canonical PlanetShape constants matching the per-body data files under models/environment/planet/data/src/ in JEOD v5.4.0.

Structs§

BodyAttitude: RootInertial → body attitude of vehicle V, witnessed unit-norm and scalar-first / left-transformation (JEOD canonical).
BodyFrame: Body (CoM-centered) frame of vehicle V. Rotates with the vehicle.
Earth: Planet marker for Earth.
Ecef: Earth-centered Earth-fixed frame (ITRF-like). Rotates with Earth.
FrameTransform: Proper rotation taking vectors expressed in From to the same vectors expressed in To.
GMST: Greenwich Mean Sidereal Time (angle, but seconds-ized by convention).
GPS: GPS Time (TAI − 19 s).
GravParam: Gravitational parameter μ = GM tagged with the source planet P.
HarmonicDegree: Spherical-harmonic degree or order index. Unitless ordinal.
InertiaTensor: Mass moment of inertia tensor (kg·m²) expressed in frame F.
IntegOrigin: The integration-frame origin: position and velocity of the integration-frame origin expressed in root-inertial coordinates.
IntegrationFrame: A body’s integration frame — a non-rotating quasi-inertial frame whose origin generally differs from the root inertial origin.
LeftTransform: r' = q r q⁻¹ — the JEOD convention.
Lvlh: Local Vertical / Local Horizontal frame relative to chief vehicle Chief. Z axis points planet-ward; Y opposes orbital angular momentum; X completes the right-handed triad (approximately along-track in near-circular orbits).
Mars: Planet marker for Mars.
MassNode: Mass-tree wildcard inertial-flavor frame for kinematic-propagation scratch state.
Moon: Planet marker for Moon.
Ned: North-East-Down topocentric frame relative to chief vehicle Chief.
NormalizedQuat: A quaternion witnessed to have unit norm at construction time.
PlanetFixed: Planet-fixed frame for any planet P. Rotates with that planet.
PlanetInertial: A particular planet’s inertial (non-rotating, J2000-aligned) frame, centered at the planet’s CoM.
Qty3: Componentwise 3-vector: each of x, y, z carries the dimension D, and the whole vector carries the frame tag F.
Quat: Quaternion tagged with its storage layout and transformation convention.
RightTransform: r' = q⁻¹ r q — the opposite of JEOD; common in many textbooks.
RootInertial: The simulation’s root inertial frame — the unique inertial node at the top of the frame tree.
ScalarFirst: Storage layout [q0, q1, q2, q3] where q0 is the scalar part (JEOD).
ScalarLast: Storage layout [x, y, z, w] where w is the scalar part (glam).
SecondsSince: Seconds elapsed in the named time scale, measured from that scale’s epoch.
SelfPlanet: Phantom marker for “this entity’s own planet” — used by ECS adapters whose per-entity components carry PlanetFixed<P> phantoms but whose planet identity is determined at runtime by the entity itself.
SelfRef: Phantom marker for “this entity’s own vehicle frame” — used by ECS adapters whose per-entity components carry frame phantoms but whose vehicle identity is determined at runtime by the entity itself.
StructuralFrame: Structural (geometric-origin) frame of vehicle V. Rotates with vehicle.
Sun: Planet marker for Sun.
TAI: International Atomic Time.
TDB: Barycentric Dynamical Time (relativistic correction to TT).
TT: Terrestrial Time (TAI + 32.184 s).
TimeConverter: Explicit converter between two time scales.
UT1: Universal Time 1 (Earth-rotation based).
UTC: Coordinated Universal Time (leap-second stepped).

Traits§

Array3Ext: Extension trait on [f64; 3] (raw component arrays from CSVs or JEOD initial conditions) producing frame-tagged 3-vectors.
F64Ext: Unit-construction extension on f64.
Frame: Compile-time reference frame tag.
Layout: Compile-time quaternion storage layout marker.
Planet: Compile-time planet tag used to parameterize planet-fixed frames.
TimeScale: Compile-time time-scale tag.
Transform: Compile-time quaternion transformation convention marker.
Vec3Ext: Extension trait on glam::DVec3 producing frame-tagged 3-vectors.
Vehicle: Compile-time vehicle tag used to parameterize vehicle-relative frames.

Type Aliases§

Acceleration: Acceleration in frame F. Base SI unit: m/s².
AngularAcceleration: Angular acceleration in frame F. Base SI unit: rad/s².
AngularMomentum: Angular momentum in frame F. Base SI unit: kg·m²/s.
AngularVelocity: Angular velocity in frame F. Base SI unit: rad/s.
Force: Force in frame F. Base SI unit: newtons.
JeodQuat: The JEOD canonical quaternion type: scalar-first, left-transformation.
Jerk: Jerk (time derivative of acceleration) in frame F. Base SI unit: m/s³.
MassFlowRate: Scalar mass-flow rate.
Position: Position in frame F (default: RootInertial). Base SI unit: meters.
SpecificAngMom: Scalar specific angular momentum.
SpecificEnergy: Scalar specific energy.
Torque: Torque in frame F. Base SI unit: N·m.
Velocity: Velocity in frame F. Base SI unit: m/s.