Automatic Dependent Surveillance–Broadcast in the Gulf of Mexico

Growing air traffic congestion and delays in the National Airspace System (NAS) require significant restructuring of the current Air Traffic Control (ATC) system. The Federal Aviation Administration (FAA) plans include the Next Generation Air Transportation System (NextGen), a Joint Planning Development Office multiagency effort established by Congress to transform the air transportation system into a more flexible, adaptive, and highly automated system capable of handling two to three times the current traffic. Automatic Dependent Surveillance– Broadcast (ADS–B) will provide the surveillance that NextGen needs to tackle these problems. Surveillance in today's NAS is provided by a system of terminal and en route radars. The FAA is seeking to augment this system by using ADS–B for aircraft surveillance and separation, and plans to implement ADS–B over the next 20 years to track all aircraft. ADS–B, a satellite-based system that provides accurate surveillance and state information to controllers on the ground and to the cockpits of equipped aircraft, is a key enabler of NextGen. Primary and secondary surveillance radars have provided positive position information to air traffic controllers ever since being introduced for commercial aircraft separation services in the early 1950s (see Figure 1). Improvements in radar system performance and the proliferation of coverage have served the FAA well. But radars are expensive to maintain, are subject to terrain blockage , and cannot provide coverage in areas where there is no line of sight. The accuracy of radars in determining position degrades at long range, and errors in measured separation between aircraft are introduced when different aircraft are tracked by different radars. Automatic Dependent Surveillance–Broadcast (ADS–B) to provide surveillance in the National Airspace System (NAS). Aircraft separation services are currently provided by a system of en route and terminal radars, and the performance of these radars in part dictates the separation distance required between aircraft. ADS–B is designed to provide comparable service in areas where no radar coverage exists. It will eventually be the primary surveillance source in the NAS, if it is proven to provide performance equal to or better than radar.