Aircraft use Distance Measuring Equipment (DME) to determine their distance from a point or equipment on the ground. These systems are used for navigation, determination of flight paths and are also used during landings.
Aircraft DME system works in cooperation with the ground stations, they are also automatically co-located with the ILS and VOR equipment. However, DME systems can be also installed separately. In this category, you can find reliable aircraft DME systems made by Garmin and Bendix King.