[phire]

Aircraft carriers have two systems.

The Instrument Carrier Landing System (ICLS) is basically just an upgraded version of the civilian ILS which they squashed down onto a ship. It broadcasts a beam of radio waves into the air and any aircraft can pick it up and follow the glide slope.

There is also the Automatic Carrier Landing System (ACLS), which is roughly equivalent to this system. Radar receivers on the carrier are fed into a computer, which calculates the aircraft's position and transmits back commands back to the aircraft's autopilot.

The cool part about this Transponder Landing System is that it doesn't require any equipment upgrades to the aircraft. An aircraft equiped with original ILS equipment from the 60s can use it.

[DiggyJohnson]

Adding for flavor and context: The ACLS is colloquially referred to as the "magic carpet", and we are now decades in to the classic disagreement about pilot skills versus automation. It's just in this case the consequence is splattering into the stern of a ship.