Reconstruction of Aircraft Trajectories from AMDAR Weather Reports

Abstract

t is well known that aircraft-based meteorological measurements exhibit systematic errors depending on various flight dynamic parameters. It is also widely assumed that operational Aircraft Meteorological Data Relay (AMDAR) weather reports by commercial aircraft are affected in a similar way. However, so far, it is not possible to study such systematic errors, because datasets that contain both AMDAR reports and flight dynamic variables are not available. To overcome this deficiency, a method was developed to reconstruct the flight trajectories of aircraft using just the aircraft type and operational AMDAR reports. Because AMDAR reports do not contain information on the flight plan, origin, destination, or the motion vector of the airplane, it is not possible to employ a trajectory solver as used by air traffic control. Instead, the method uses groups of trajectory templates that are fitted to AMDAR data taken during approach or departure. This algorithm allows estimation of the heading, true airspeed, aircraft mass, roll state, pitch angle, and angle of attack of the reporting aircraft for each AMDAR report. For verification, the algorithm was applied to navigation data gathered from two Airbus-manufactured aircraft, of which one is in commercial service and one is used for aviation research. From a total of 48 profiles, a very good agreement of reconstructed and measured values was found.