Using Automatic Dependent Surveillance-Broadcast Data for Monitoring Aircraft Altimetry System Error

Altimetry System Error (ASE) is a measure of the height-keeping performance of an aircraft. In airspace where the Reduced Vertical Separation Minimum (RVSM) is applied, the importance of accurate aircraft height-keeping is magnified. ASE is not detectible in routine operations; specialized measurement equipment is necessary to independently measure the errors. To be eligible for RVSM operations, operators must adhere to the height-keeping performance monitoring requirements established for the airspace in which operations are to be conducted. The Federal Aviation Administration (FAA) developed a process to monitor the height-keeping performance of aircraft for RVSM operations. The International Civil Aviation Organization (ICAO) has established long-term minimum monitoring requirements to be used by the regions where the RVSM is implemented which go into effect in November 2010. This paper progresses the work which considers the role of a Next Generation Air Transportation System (NextGen) technology, Automatic Dependent Surveillance–Broadcast (ADS-B), to monitor the height-keeping performance of aircraft. This paper contains results from test flights conducted at the FAA Technical Center to compare aircraft geometric height obtained from three sources; ADS-B, EGMU, and an onboard independent GPS reference receiver. In addition, this paper presents initial results from ADS-B data collected from real airspace operations. The ADS-B data made available for this work result from a cooperative research agreement between the FAA and Airservices Australia The results of this study will be used to determine the quality control processes needed for monitoring aircraft ASE using ADS-B geometric height data.