UAS components — the four labeled on the diagram.

• UAV — the aircraft.
• GPS — onboard positioning so the UAV knows where it is.
• Data Link — wireless two-way channel between aircraft and ground control (carries commands up and telemetry/imagery down).
• Antenna — the ground-station side of the data link.

The remote pilot in command (RPIC) sits at the ground station; together with the UAV and the link, these four elements are the minimum UAS.