Unmanned Aerial Vehicle
Unmanned Aerial Vehicles (UAV), in the most literal definition, are powered aerial vehicles, which do not carry humans, can be either remote-controlled by human operators or operate under its own computer control, and can carry lethal or nonlethal payloads (i.e., weapons and sensors). They must use aerodynamic forces in conjunction with their power plant.
From a human factors standpoint, as are unmanned ground vehicles and unmanned underwater vehicles, it is a telepresence application. There is an assumption there will be at least one-way, if not two-way, communications between people and the UAV. The first UAVs were under continuous human control, but more advanced types have autonomous guidance for at least part of their mission. The most basic form of autonomous guidance is the use of an autopilot for the more routine, midcourse part of a flight, once at cruise altitude and before its final mission(s) begin. More advanced UAVs may guide themselves in the actual reconnaissance or attack phases of their mission, much as a guided missile often is responsible for its terminal phase.
Unmanned Aerial System
While the UAV term is most common, the U.S. Department of Defense and Federal Aviation Administration prefers the term Unmanned Aerial System, since UAVs are not very practical without supporting subsytems. Very few people actually use the term UAS, but the Such subsystems include:
- UAVs proper
- Launching and retrieval equipment
- Remote control or programming facilities
- Communications links with the UAV
- People to run the entire system.
Military UAV types
UAV versus PGM
UAVs are not generally considered precision-guided munitions, although the distinction blurs when considering expendable UAVs. Armed UAVs routinely carry PGMs and drop them after the target is confirmed, the first known use being the AGM-114 Hellfire missiles carried by MQ-1 Predator UAVs, operated by the Central Intelligence Agency. A Predator/Hellfire combination destroyed an al-Qaeda vehicle in 2002.
The line gets quite blurry when trying to decide if an advanced cruise missile, which can get in-flight course changes, or can send back information indicating if it hit the target. One example of the latter is a cruise missile that deploys a television camera on a trailing cable, with the camera existing just long enough to send back video of the missile's impact.
Ballistic or semiballistic projectiles, be they intercontinental ballistic missiles or guided howitzer/mortar shells, are not considered UAVs because they are not self-powered. That some unpowered guided shells do use aerodynamic control surfaces does not qualify them as a UAV.