Module orbit 

Compact orbit approximations.

Reduced orbits are fitted approximations for caching, transport, and quick visibility math. They are not precise ephemeris products; use crate::ephemeris::Sp3 or crate::ephemeris::BroadcastEphemeris when full-fidelity products are available.

Structs

CalendarEpoch

A UTC calendar instant (year, month, day, hour, minute, second), the form the core TimeScales::from_utc consumes. The Elixir layer produces these from each sample/query epoch; no Instant->TimeScales bridge exists in the core crate, so the calendar tuple is carried explicitly to the boundary.

DriftEntry

A per-epoch drift entry: the model-vs-truth position error at one epoch.

DriftReport

The result of a source-backed drift evaluation.

EcefSample

One fitting/drift truth sample: an epoch and an ECEF (ITRF) position in meters.

Elements

The fitted mean elements plus the kept J2 seed.

FitStats

Residual statistics from a fit, in meters.

PiecewiseOrbit

A long span represented by contiguous independently-fitted reduced-orbit segments.

PiecewiseSegment

One fitted segment in a piecewise reduced-orbit model.

ReducedOrbit

A fitted model: elements plus the residual statistics of the fit.

Enums

Frame

Which reference frame a position/velocity result is expressed in.

Model

Which mean-element model the fit and evaluation use.

PiecewiseOrbitError

Errors from fitting or evaluating a piecewise reduced orbit.

ReducedOrbitError

Errors from fitting or evaluating a reduced orbit.

Constants

MIN_SAMPLES

Minimum number of samples the fitter accepts. The circular model solves five free elements and the eccentric model eight; each ECEF sample contributes three residuals, so four well-spread samples (twelve residuals) is the floor. Below this the geometry seed and refinement are unreliable.

Functions

drift

Evaluate the model against truth ECEF samples and report the per-epoch error, its statistics, and the first epoch the error crosses threshold_m.

fit

Fit the default circular_secular model to ECEF samples, with all epochs interpreted in scale (e.g. an SP3 product’s GPST).

fit_piecewise

Fit contiguous reduced-orbit segments over [t0, t1].

fit_with_model

Fit a chosen Model to ECEF samples interpreted in scale.

piecewise_drift

Evaluate a piecewise model against truth ECEF samples.

piecewise_position

Evaluate a piecewise reduced orbit at epoch.

piecewise_position_velocity

Evaluate piecewise reduced-orbit position and velocity at epoch.

position

Evaluate the model position at epoch (interpreted in scale) in the requested frame, meters.

position_velocity

Evaluate the model position and velocity at epoch in the requested frame. Returns (position_m, velocity_m_s). ECEF velocity includes the Earth-rotation transport term.

select_piecewise_segment

Return the segment covering epoch.

Type Aliases

Error

Error type returned by reduced-orbit fitting/evaluation.

ReducedOrbitModel

Role-oriented alias for a fitted reduced-orbit model.