ENR 4: Navigation Aids/Systems ▶ ENR 4.1 Navigation Aids - En Route 1. Nondirectional Radio Beacon (NDB) 2. VHF Omni-directional Range (VOR) 3. VOR Receiver Check 4. Distance Measuring Equipment (DME) 5. Tactical Air Navigation (TACAN) 6. Instrument Landing System (ILS) 7. Compass Locator 8. ILS Frequency 9. ILS Minimums ▶ ENR 4.2 Special Navigation Systems 1. Doppler Radar ▶ ENR 4.3 Global Navigation Satellite System (GNSS) ENR 4.3: Global Navigation Satellite System (GNSS) ▶ ENR 4.4 Name-Code Designators for Significant Points 1. Data Set 2. Alphanumeric Waypoints ▶ ENR 4.5 Aeronautical Ground Lights — En-Route ENR 4.5: Aeronautical Ground Lights — En-Route