DME Navigation System

DME Navigation System

1. Role

   • Airborne DME
     • Interrogator
   • DME Ground Station
     • Transponder

2. Unit of Measurement

   • Slant Range
     • in nautical miles
   • Time to Station
     • in hour minute second
   • Ground Speed
     • in nautical miles per hour

3. Airborne DME

   • Control Panel
   • Transceiver
   • Antenna
   • Display

4. Channels

   • X Channel
     • 12us pulse pair spacing
     • Ground signal is 63 MHz higher than Air signal
   • Y Channel
     • 36us pulse pair spacing
     • Ground signal is 63 MHz lower than Air signal

5. Radio Frequencies

   • 960 MHz and 1215 MHz
   • DME frequency is paired with VOR frequency

6. Slant Range Error

   • Minimal
     • Fly Far
     • Fly Low
   • Significant
     • Fly Close
     • Fly High

7. Computation

   • (120µs - 50µs) / 12.35µs nm

8. Ground Station

   • Civilian
     • VOR/DME
       • Slant Range
       • Bearing
     • ILS/DME
       • DME replaces Marker Beacons
   • Military
     • TACAN
       • Slant Range
         • Share with Civilian
       • Bearing