ADS-B: Enabling the Next Momentous Transformation in Air Traffic ControlAugust 2013
This dramatic change involves the shift from a radar-based system to one taking advantage of the global satellite network. A key part of this evolution is a technology MITRE has supported since its earliest days: Automatic Dependent Surveillance-Broadcast, or ADS-B.
The ADS-B system enables airplanes to transmit information on their location, speed, and altitude to other planes in their vicinity and to ground stations connected to air traffic control centers. The system uses Global Positioning System (GPS) technology to determine a plane's location and whether it's climbing, descending, or turning—broadcasting this data in real time.
Using this information, pilots can maintain situational awareness of other aircraft around them. This allows for safer and more efficient flights. With radar, only controllers on the ground could see what was happening in the airspace. ADS-B enables another set of eyes because both the pilots and controllers will see a consistent airspace surveillance picture.
Air traffic controllers and ground automation systems also benefit from a highly accurate depiction of the aircraft's position, speed, and direction. This will lead to safer operations and improved efficiencies through the procedural applications of ADS-B in the future. Improvements are already being realized by university flight training programs, Alaska air taxi operators, and in Gulf of Mexico operations. For example, in the Gulf, ADS-B enables controllers to see helicopter traffic servicing oil platforms, permitting higher traffic density and reducing delays. This means helicopter fleet operators are saving fuel via more direct routing.
Our groundbreaking work on this program, begun in the early 1990s and undertaken with 25 government and industry partners, was recognized in 2008 when ADS-B received the most prestigious honor in aviation: the Robert J. Collier Trophy. In the past, this award has gone to such pioneers as Orville Wright, Howard Hughes, Chuck Yeager, and the crew of Apollo 11.
MITRE's Leadership Role
From the project's inception, MITRE has played a vital role in the ADS-B vision and concept development, helping with the design, engineering, and architecture of ADS-B, along with prototype design and fielding. ADS-B system prototypes were developed and shown to be viable in the mid-1990s.
In the early 2000s, MITRE spearheaded an extensive testing program in Alaska called the Capstone demonstration system. This was an effort with two purposes: to prove the ADS-B technology operationally and also improve aviation safety in Alaska, where bad weather, harsh geography, and inadequate equipment often made flying dangerous and aviation accidents commonplace. This work involved the installation of ground infrastructure, GPS-based avionics, and data link communications in commercial aircraft serving remote parts of the state.
MITRE worked closely with the Alaskan aviation industry, the FAA, manufacturers, controllers, pilots, contractors, and others. Together, they deployed the initial system, developed Capstone software and infrastructure, and tested the emerging ADS-B system.
On January 1, 2001, the Anchorage Air Route Traffic Control Center received the first ADS-B position report and vectored two aircraft to the airport in Bethel without the use of surveillance radar. This historic event paved the way for further testing in the state. As a result of the Capstone work, the accident rate in the ADS-B-equipped portion of Alaska's airspace fell by nearly 50 percent between 2000 and 2005.
A key component to the program's success was MITRE's research into the avionics necessary for providing ADS-B services. Our invention of the Universal Access Transceiver (UAT), a device that can communicate with the ground and with nearby aircraft to exchange ADS-B and weather data, represented an important leap forward for the overall system.
MITRE designed the UAT, a wideband data link technology operating on a single global channel, to provide a communications system with a simple and robust design based on proven techniques. UAT uses readily available components to keep costs down and can be incorporated into radios in small and low-flying aircraft. These types of aircraft are prominent in Alaska and the rest of the United States. Prior to the Capstone program, MITRE licensed the UAT technology to IIMorrow Corporation (as acquired by Garmin Ltd.), who subsequently won a competitive bid from the FAA for commercial production of the avionics used in the Capstone demonstration system.
Wider Implementation of ADS-B
In 2005, the FAA determined that the ADS-B technology had been proven and was ready to operate throughout the National Airspace System. Today, single- and twin-engine aircraft in the U.S. and commercial airlines throughout the world use ADS-B. In the United States, the ADS-B infrastructure was completed in 2014. In recent years, multiple new avionics companies have entered the market, and UAT avionics are now widely available. UAT-based ADS-B systems are being installed to meet the FAA's rapidly approaching 2020 ADS-B airspace access rule, which requires aircraft operating around busy airports and above 10,000 feet to transmit ADS-B information.
ADS-B's ongoing development and wider implementation on flight deck applications will improve flight efficiency for aircraft operators. The FAA believes the gains in safety and efficiency expected to result from widespread implementation of ADS-B will also help it meet the growth in air traffic in the coming years..