Aircraft Navigation Basics 1/C MQS

Two Schools of Air Nav  Visual Flight Rules (VFR)  Navigation accomplished primarily by visual reference to the ground (charts, DR)  Requires at least 1000 ft. cloud ceiling and 3 miles of visibility (must be able to see where you’re going!)  Basic pilot training/certification  Instrument Flight Rules (IFR)  Navigation accomplished primarily by reference to onboard instruments, electronic navigation aids, and Air Traffic Control  No weather minimums  More advanced pilot training/certification required

Methods of AirNav  Visual (“Pilotage’)  Dead Reckoning  “Course Rules” (preplanned routes based on major landmarks)  Charts  Global Navigation Satellite System  GPS  GLONASS  Radio Beacons  Automatic Direction Finder (ADF)/Non-Directional Beacon (NDB)  Very-High Frequency Omnidirectional Range (VOR)  Tactical Air Navigation (TACAN)  RADAR Surveillance  Air Traffic Control  Airborne/Shipboard RADAR

Visual Flight Rules  VFR Charts Display  Major landmarks/obstacles  Airports and relevant information  Population centers  Major roads  Airspace dimensions

Global Positioning System (GPS)  Primary navigation method for modern aircraft  Minimal error  Can be used for precision landings  Worldwide coverage

Non-Directional Beacon (NDB)  Fixed ground station provides basic “bearing to” information  Greater range but less precision than other methods  Aircraft can use signal to “home” on the station

Radio Navigation VHF Omnidirectional Range (VOR)  Ground station emits directional radio signals 360° around station  Offers more precise course guidance  Line-of-Sight (LOS) dependent  Provides aircraft with a line of position to/from the station (“radial”)  Multiple station fixes can be used to triangulate position

TACAN (TACtical Air Navigation)  Available to military users only  Ground or ship-based  Provides bearing AND range information  Distance Measuring Equipment (DME) onboard aircraft sends and receives signals to ground station to determine range (similar to active SONAR).  Distance provided is “slant range” distance, which is not the same as distance over the ground!

RADAR Surveillance  Navigation function performed by RADAR stations  Ground facilities  Airport towers  Approach/Departure Control  Air Route Traffic Control Centers (ARTCC)  Ships  CIC  ASW/ASUC Tactical Air Controller (ASTAC)  Aircraft  E-2 Hawkeye  E-3 AWACS  Primary function is aircraft separation and airspace management  Requires two-way communication  Severe weather avoidance available

Signals Degradation  Navigational data is typically provided simultaneously, providing redundancy and enhanced reliability.  Any of the navigational aids utilized by aircraft are vulnerable to attack/jamming/compromise.  In a degraded signals environment, aircraft navigation and operational performance will suffer as data inputs are reduced or eliminated altogether.  Many modern weapon systems – such as the GPS guided JDAM – are similarly vulnerable to a degraded environment.

Review  Two categories of aircraft navigation  Visual Flight Rules (VFR)  Instrument Flight Rules (IFR)  Methods of aircraft navigation  Dead reckoning, visual orientation, “pilotage”  GNSS (GPS)  Radio beacon (NDB, VOR, TACAN)  RADAR Surveillance  Signals degradation  Navigational accuracy and operational performance are degraded when input signals are jammed or compromised