`orbitalgym.groundstations`¶

Ground-station network and contact-schedule primitives.

Network types¶

orbitalgym.groundstations.network.GroundStation ¶

A single ground station — Earth-fixed lat/lon/alt + elevation mask.

name is a Python-level string (not a traced array) so it stays usable by visualization and logging without escaping the JAX trace.

orbitalgym.groundstations.network.ContactSchedule ¶

Precomputed contact windows for one side over the episode horizon.

windows is a fixed-shape padded array so in_contact_now runs in JIT without Python control flow. Sentinel rows have t_end <= t_start and are guarded by the per-row idx < n_valid mask.

orbitalgym.groundstations.network.GroundStationNetwork ¶

A side's network — static-tuple stations + their precomputed schedule.

schedule is filled by precompute_contact_schedule (in contacts.py) at scenario construction. Construction without a schedule is allowed for tests that don't exercise contacts; production code goes through the builder.

Contact computation¶

The runtime predicate in_contact_now is pure JAX and JIT-stable; the brahe-backed builder precompute_contact_schedule runs once at scenario construction.

orbitalgym.groundstations.contacts.precompute_contact_schedule ¶

precompute_contact_schedule(
    stations: tuple[GroundStation, ...],
    reference_orbit: ReferenceOrbitState,
    epoch_mjd_utc: float,
    horizon_s: float,
    *,
    pad_to: int = 256,
) -> ContactSchedule

Build a ContactSchedule from per-station brahe queries.

Calls brahe once per station, concatenates the per-station window lists, sorts ascending by start time, pads to pad_to rows with sentinels.

Raises ValueError if the total window count exceeds pad_to.

orbitalgym.groundstations.contacts.in_contact_now ¶

in_contact_now(
    schedule: ContactSchedule, t: Array
) -> jax.Array

Scalar bool: is t inside any valid contact window?

Open-closed semantics: t_start <= t < t_end. Pure JAX — single jnp.any over the padded (N_max, 2) array, gated by an idx < n_valid mask so sentinel rows never match.

orbitalgym.groundstations¶