Air Traffic Control Services
- Airport Traffic Control Towers (ATCT)
- Terminal Radar approach Control (TRACON) Facilities
- Air Route Control Centers (ARTCCs)
Basic Navigational Aids
VHF Omni directional Range (VOR) and Distance Measuring Equipment (DME) stations which transmit signals along "airways", highways in the sky, to route air traffic.
Instrument Landing System (ILS)
Instrument Landing System (ILS), which is a precision approach and landing aid that normally consists of a localizer, a glide slope, marker beacon, and an approach light system.
Airport Surveillance Radar (ASR)
This is used in conjunction with a transponder radar beacon device, is an approach control radar system used to separate aircraft within the immediate vicinity of an airport; it normally has a maximum range of 60 nautical miles.
Performance Based Navigation (PBN)
The arrival of GPS navigation tools has caused a major restructuring of ATC procedures. The FAA has recently announced its strategic goal to make PBN the nation's primary means of navigation in the next 15 years.
Area Navigation (RNAV)
Describes different technologies that enable aircraft navigation on any desired course within the coverage of specific navigation signals. RNAV consist of station-to-station navigation, or it may be between random waypoints offset from published routes depending upon the type of equipment used.
Required Navigation Performance (RNP)
Is a type of PBN that allows an aircraft to fly a specific path between two 3-D defined points in space. RNAV and RNP systems are fundamentally similar, the key difference between them is the requirement for RNP onboard performance monitoring while flying curved approach paths to an airport.
GPS Equipment Enhancement
The current U.S. Aviation navigation system is compromised of more than 4,300 ground-based systems whose signals are used by aircraft avionics for en route navigation and landing guidance. Over the next several years, the navigation system is expected to increase its use of GPS satellites, augmented by ground monitoring stations, to provide navigation signal coverage throughout the National Airspace System (NAS). The transition to satellite- based navigation consists of the following:
Global Positioning System
Used for enroute terminal navigation and non precision approaches. GPS is a radio navigation system composed of 24 orbiting satellites that provide extremely accurate three-dimensional position, velocity, track and time at low cost so that even general aviation planes can use it.
Wide Area Augmentation System (WAAS)
Provide enroute/terminal navigation and category (CAT) I precision approaches. WAAS enhances GPS signals to provide more precise location information to an accuracy approximately 3 meters. WAAS is designed to use reference stations covering wide areas throughout the United States to cross check GPS signals and then relay integrity and correction information to aircraft via geostationary communication satellites.
Types of Instrument Approaches
- Non Precision Approach- This is an instrument approach procedure based on lateral path and no vertical guidance.
- Precision Approach- This is an instrument approach procedure based on lateral path and vertical guidance.
- Category I- Category I is a precision instrument approach and landing with a decision height that is not lower than 200 feet above the threshold and visibility of no less than 1/2 mile.
- Category II- is a precision instrument approach and landing with a DH lower than 200 feet, but no lower than 100 feet and with a Runway Visual Range of not less than 1200 feet.
- Category III- is a precision instrument approach and landing with a DH lower than 100 feet or no DH, and with an RVR less than 1200 feet.
Weather Automation Systems
Weather conditions interfere with flight operations and contribute to aviation accidents more than any other factor. The key to reducing weather-related accidents is to improve pilot decision making through increased exchange of timely information. Currently there are a variety of systems that help maintain aviation safety:
- Integrated Weather System (ITWS)
- Weather and Radar Processor (WARP)
- Next Generation Weather Radar (NEXRAD)
- Terminal Doppler Weather Radar (TDWR)
Integrated Terminal Weather System (ITWS)
Automated weather system that provides near-term (0 to 30 minutes) prediction of significant terminal weather for major terminal locations.
Weather and Radar Processor
Integrated system that receives and processes real time weather data from multiple sources and provides weather information for use by the ARTCCs and Air Traffic Control Command Center (ATCSCC) to support the en route environment.
Next-Generation Weather Radar and Terminal Doppler Weather Radar
NEXRAD is a national network of Doppler Weather Radar to detect, process, distribute and display hazardous weather, providing more accurate weather data for aviation safety and fuel efficiency. This radar has a 250 mile range and the network covers the majority of the domestic en route airspace.
Operational Planning Improvements
To improve flight planning, the FAA has introduced new and improved information services in the areas of Traffic Flow Management (TFM) and flight services that enable collaboration service providers and users sharing the same data and negotiating to find the best solutions to meet operational needs.
Automated Flight Service Stations (AFSSs)