Air Combat Maneuvering Instrumentation (ACMI) systems record an aircraft's in-flight data.
Autonomous air combat maneuvering instrumentation (AACMI) are second-generation GPS-based ACMI systems.
Recording of aircraft tracks can therefore be independent of ground-based radar, and are sometimes called range-less or autonomous.
This enables real-time air-to-air exercises to be carried out and also complex ground debriefs (after-action review or AAR) based on data recorded at the time.
Such de-briefs involve the use of modern graphics and display techniques that can bring out training and other points to aircrew and ground staff.