Orbital Terms
| Term | Meaning |
|---|---|
| Apogee / perigee | Farthest / nearest orbital point from Earth |
| Inclination | Angle between the orbital plane and the equatorial plane |
| Sub-satellite point | Point on Earth directly below the satellite |
| Footprint | Earth area covered by the satellite antenna beam |
| Elevation angle | Antenna angle above the local horizon |
| Azimuth angle | Horizontal pointing angle measured from north |
| Look angle | Azimuth and elevation needed to point at the satellite |
| Station keeping | Holding the assigned orbital position against perturbations |
Orbital terms.
Footprint: depends on satellite altitude, antenna beamwidth and Earth geometry: GEO satellites have large fixed footprints, whereas LEO satellites sweep smaller, moving footprints across the ground.