1) The scientific study of sound and sound waves.  2) The characteristics of a room that determine the audibility of sound within it.

  An FAA informational publication for non-regulatory policy and guidance material.

  Aircraft operating in flight or on airport runways.

  A federal government service operated by the FAA that facilitates the safe and orderly movement of aircraft within and between airports by receiving and processing data from radar and devices that m [..]

  Radar system used at airports to detect and display the position (distance & direction) of aircraft in the airport terminal area.

  Height above ground level.

  Height about mean sea level - 0 feet.

  Also known as Background Noise.  A composite of all noise sources in an area.  For aviation studies, aircraft noise is not included as a noise source.

  Formerly called Random Navigation. A method of navigation that allows aircraft to choose any course within a network of navigation beacons, rather than navigating to/from the beacons.

  Landing at an airport.