| name | satellitetoolbox-propagators |
| description | SatelliteToolboxPropagators.jl providing a unified API for analytical orbit propagators (TwoBody, J2, J4, SGP4). Use when propagating orbits with analytical models, fitting mean elements, or comparing propagator outputs. |
SatelliteToolboxPropagators.jl
Unified API for analytical orbit propagators. Repo: JuliaSpace/SatelliteToolboxPropagators.jl
Available Propagators
| Symbol | Type | Description |
|---|
:TwoBody | OrbitPropagatorTwoBody | Keplerian two-body |
:J2 | OrbitPropagatorJ2 | J2 mean elements |
:J2osc | OrbitPropagatorJ2Osculating | J2 with osculating output |
:J4 | OrbitPropagatorJ4 | J4 mean elements |
:J4osc | OrbitPropagatorJ4Osculating | J4 with osculating output |
:SGP4 | OrbitPropagatorSgp4 | SGP4/SDP4 from TLE |
Initialize and Propagate
# Init from KeplerianElements or orbital parameters
orbp = Propagators.init(Val(:J2), orb)
orbp = Propagators.init(Val(:J2), epoch_jd, a, e, i, Ω, ω, f)
# Init from TLE (SGP4 only)
orbp = Propagators.init(Val(:SGP4), tle)
# Propagate by Δt seconds from epoch
(r_i, v_i) = Propagators.propagate!(orbp, Δt)
# Propagate to a specific epoch
(r_i, v_i) = Propagators.propagate_to_epoch!(orbp, jd)
# Step from current time (not epoch)
(r_i, v_i) = Propagators.step!(orbp, Δt)
# One-shot: init + propagate
(r_i, v_i, orbp) = Propagators.propagate(Val(:J2), Δt, epoch_jd, a, e, i, Ω, ω, f)
Return as OrbitStateVector
sv = Propagators.propagate!(orbp, Δt, OrbitStateVector)
Vectorized Propagation
(vr, vv) = Propagators.propagate!(orbp, [0.0, 60.0, 120.0]; ntasks=4)
Fitting Mean Elements
mean_elements = Propagators.fit_mean_elements(Val(:J2), vjd, vr_i, vv_i)
Query Propagator State
Propagators.epoch(orbp) # Epoch [JD]
Propagators.last_instant(orbp) # Last propagation time [s]
Propagators.mean_elements(orbp) # Current mean elements
Propagators.name(orbp) # Propagator name string
Key Conventions
- Units: meters, m/s, seconds for Δt, Julian Day for epochs
- Propagator selection via
Val(:Symbol) dispatch
Dates.Period inputs auto-converted to seconds- Output frame: inertial (ECI) for analytical propagators, TEME for SGP4
- Re-exports SatelliteToolboxBase and SatelliteToolboxSgp4
