Vehicle¶

The vehicle asset represents a ground-mobile platform such as an aircraft, ship, rover, or other moving asset. It behaves like a physical asset from the analysis and visualization point of view, but its motion is produced from a geodetic waypoint trajectory rather than an Orekit orbit propagator.

Role in ASTROLAB¶

Workflow	Vehicle role
2D/3D visualization	Moving ground asset with position, velocity, attitude, and optional 3D model.
Link analysis	Mobile endpoint for contact or RF links.
Coverage or access	Moving source or target when compatible with endpoint logic.
Mounted payloads	Parent for sensors, antennas, transmitters, receivers, and solar arrays.

Architecture¶

flowchart TD
    V["VehicleAsset"] --> W["Waypoints"]
    V --> T["VehicleTrajectoryService"]
    T --> G["Geodetic state at time"]
    G --> I["ITRF position"]
    I --> F["Requested frame transform"]
    G --> A["Velocity-based attitude"]
    F --> P["PoseSnapshot"]
    A --> P

Main Parameters¶

Field	Meaning
`initial_date`	Start date of the trajectory.
`waypoints`	List of geographic waypoints used to define the route.
`trajectory_method`	Trajectory construction method, currently speed-oriented.
`attitude_mode`	Body frame alignment convention.
`constraints`	Access/environment constraints attached to the vehicle.
`color_hex`	Visualization color.
`model_3d_path`	Optional 3D model path.

Attitude Modes¶

Mode	Description
`ecf_velocity_alignment`	X body follows ground velocity; Z body points local Up.
`ecf_velocity_radial`	X body follows ground velocity; Z body follows geocentric radial outward direction.
`ecf_velocity_nadir`	X body follows ground velocity; Z body points local Nadir.

Timeline Bounds¶

The vehicle exposes native time bounds from the waypoint trajectory. Outside those bounds, pose queries return no valid state.

Best Practices¶

Define enough waypoints to avoid unrealistic sharp route changes.
Use a trajectory interval that overlaps the scenario interval.
Attach communication or observation equipment as children when modelling mobile platforms.
Validate trajectory visualization before using the vehicle in long analyses.