Gallery¶

Runnable examples — four producer archetypes and three annotation entities. Each lives under examples/ and writes a .czml you can open in any Cesium client — see viewing the output.

Run them from the repository root with the package installed:

python examples/leo_ground_track.py
python examples/geo.py
python examples/skyfield_tle.py      # needs Skyfield: pip install skyfield
python examples/lunar_transfer.py
python examples/contacts_mission.py
python examples/maneuver_mission.py
python examples/attitude_mission.py

The images below are rendered with Cesium ion world imagery.

LEO with ground track — from a GMAT ephemeris¶

The flagship interop case: a trajectory GMAT already computed, read from a CCSDS-OEM and converted with the ground track enabled.

A GMAT LEO ephemeris animated in Cesium with its ground track

from orbit_formats import read
from gmat_czml import to_czml

trajectory = read("examples/data/gmat-leo.oem")
to_czml(trajectory, ground_track=True).save("leo-ground-track.czml")

Source: examples/leo_ground_track.py.

A geostationary orbit — built in code¶

Not every producer is a file reader. This one builds a circular geostationary orbit directly as the canonical schema, proving the schema — not a GMAT file — is the real input contract.

A geostationary orbit rendered in Cesium

Source: examples/geo.py.

A non-GMAT producer — an ISS TLE via Skyfield¶

A TLE propagated by Skyfield — no GMAT anywhere — through the same one call, ground track included.

An ISS orbit and ground track in Cesium

Source: examples/skyfield_tle.py.

A lunar transfer — out past the Moon, from GMAT¶

The deep-space case. GMAT targets a full translunar mission — a low-perigee departure, a trans-lunar injection, a powered swing past the Moon, and capture into lunar orbit — and writes it as a four-segment CCSDS-OEM in Earth-centred EME2000. orbit-formats reads the segments as one continuous state series, and the same one call turns the whole eight-day voyage into a scene that reaches past lunar distance.

A translunar transfer trajectory drawing itself out from Earth to the Moon in Cesium

from orbit_formats import read
from gmat_czml import to_czml

trajectory = read("examples/data/gmat-lunar-transfer.oem")
to_czml(trajectory, playback_seconds=90).save("lunar-transfer.czml")

The scene spans ~400,000 km, so the viewer zooms out until Earth is a bright point and the path fills the frame; the Moon's gravity shows as the bend where the trajectory swings around and captures. The trajectory is Earth-centred — gmat-czml renders the geometry GMAT computed, it does not model the third body — and the ground track is left off, as an Earth-surface projection is meaningless out at lunar distance. Source: examples/lunar_transfer.py.

Contacts — ground stations and a windowed line of sight¶

The GMAT LEO again, with two ground stations and the access windows between each station and the satellite. Each observer is placed on the globe, and a line of sight is drawn only while the station can see the spacecraft — so a link appears as the pass begins and clears when it ends.

Two ground stations and a line of sight to the satellite during a pass

from orbit_formats import read
from gmat_czml import Contact, GroundStation, to_czml

trajectory = read("examples/data/gmat-leo.oem")
contact = Contact(observer=GroundStation("Station-A", latitude=45.5, longitude=-9.9), target="GmatLeo", windows=windows)
to_czml(trajectory, contacts=[contact], ground_track=True).save("contacts.czml")

The example computes plausible windows by placing each station beneath the satellite at a chosen instant; a real mission gets them from an access tool. See Contacts. Source: examples/contacts_mission.py.

Maneuvers — impulsive and finite burns¶

An impulsive burn pinned on the orbit where it happens, and a finite burn drawn as a highlighted arc over the span it fires, each labelled with its Δv.

An impulsive maneuver marker and a finite-burn arc on a LEO orbit

from orbit_formats import read
from gmat_czml import to_czml

trajectory = read("examples/data/gmat-leo.oem")
to_czml(trajectory, maneuvers=maneuvers).save("maneuvers.czml")

maneuvers is an iterable of orbit-formats Maneuver records, read from a CCSDS OPM / OCM. See Maneuvers. Source: examples/maneuver_mission.py.

Attitude — the body axes turning over the orbit¶

A spacecraft attitude history rendered as an animated orientation: the body box turns to the spacecraft's orientation at each instant as the playhead moves along the orbit.

A spacecraft body box turning over its orbit

from orbit_formats import read
from gmat_czml import to_czml

trajectory = read("examples/data/gmat-leo.oem")
attitude = read("spacecraft.aem")   # a CCSDS-AEM quaternion history
to_czml(trajectory, attitude=attitude).save("attitude.czml")

The example synthesizes a slow body-Z roll so it stays self-contained; a real mission reads the quaternion history from an AEM. See Attitude. Source: examples/attitude_mission.py.

Rendering these images¶

The screenshots and GIF here are produced headlessly by scripts/render_gallery.py, which runs the examples, loads each output in the bundled viewer, and captures the frames. The committed images are what this site embeds, so building the docs never needs a browser.