Facility

The facility asset represents a fixed ground site on the Earth ellipsoid. It is the preferred asset for ground stations, ground antennas, control centers, observatories, and any fixed infrastructure that participates in access or link analysis.

Role in ASTROLAB

Workflow	Facility role
Link analysis	Ground endpoint for spacecraft-to-ground or ground-to-space links.
Coverage validation	Reference site for visibility checks.
Mounted RF assets	Parent for antennas, transmitters, and receivers.
Constraints	Owner of elevation and azimuth constraints.

Spatial Model

flowchart LR
    G["Geodetic lat/lon/alt"] --> I["ITRF Cartesian position"]
    I --> F["Transform to requested frame"]
    G --> E["Local ENU body frame"]
    F --> P["PoseSnapshot"]
    E --> P

Main Parameters

Field	Meaning
geodetic.lat_deg	Facility latitude in degrees.
geodetic.lon_deg	Facility longitude in degrees.
geodetic.alt_m	Altitude above the ellipsoid in meters.
color / color_hex	Visualization color.
model_3d_path	Optional 3D model path.
model_scale	Scale applied to the optional 3D model.
constraints	Facility-level constraints.

Body Frame Convention

Axis	Direction
X body	East
Y body	North
Z body	Up

This ENU convention makes facilities compatible with mounted assets such as antennas and sensors.

Typical Constraints

Constraint	Use
Elevation	Enforce ground station minimum elevation.
Azimuth	Restrict visibility to an azimuth sector.
Range	Limit maximum operational range.