Mounted Assets

Mounted assets are child objects that inherit position and velocity from a parent physical asset, while adding their own mounting orientation and dynamic pointing model. Sensors and antennas use this architecture.

Pose Composition

The mounted asset pose is built from three rotations:

flowchart LR
    A["Parent model to frame"] --> B["Mount rotation"]
    B --> C["Dynamic pointing rotation"]
    C --> D["Mounted asset model to frame"]

Conceptually:

q_mounted = q_parent * q_mount * q_pointing

The returned quaternion uses the ASTROLAB convention [w, x, y, z] and represents an active rotation into the requested frame.

Common Mounted Asset Parameters

Field	Meaning
parent_guid	GUID of the physical parent asset.
mounting.mode	Mounting definition mode. Currently Euler-based.
mounting.sequence	Euler sequence such as 321.
mounting.angles_deg	Nominal mounting angles in degrees.
attitude_mode	Dynamic pointing mode.
attitude_params	Parameters for the selected pointing mode.
target_guid	Optional target used by targeted pointing.
target_pointing_fallback	Fallback mode if target pointing cannot be solved.
fallback_attitude_params	Parameters for fallback pointing.
constraints	Optional constraints applied at mounted-asset level.

Pointing Modes

Mode	Description	Typical use
Body-Fixed	Mounted frame remains fixed relative to parent body.	Fixed antennas, fixed sensors, panel-like hardware.
Scan 1D	Rotates according to a one-dimensional scan pattern.	Sweeping payloads or survey sensors.
Conical Scan	Performs conical/spinning pointing motion.	Search or acquisition modes.
Targeted	Attempts to point toward a target asset.	Tracking antennas, targeted sensors.

Timeline Inheritance

Mounted assets do not define their own independent timeline. Their natural time bounds come from the parent asset. This is important when analyses select asset intervals or when viewers animate mounted geometry.

Best Practices

• Define the parent asset first and validate its attitude convention.
• Keep mounting angles simple until the parent frame is verified.
• Use targeted pointing only when the target asset has valid state over the same timeline.
• Attach constraints to the mounted asset when the limitation belongs to the payload, not the bus.