Reconstruction of aircraft trajectories during landing using a rauch-Tung-striebel smoother, instrument landing system deviation information, and taxiway locations

A device called Quick Access Recorder collects huge amount of data during flight of civil aircraft. After flight, the data are transferred to ground stations where they are stored and analyzed by the airline. These investigations focus, beyond others, on flight safety, efficiency and maintenance aspects. For many of these analyses, the position of the aircraft, especially during the landing period, is a crucial input. In general, any recorded data contains uncertainties and errors, which often leads to an unsatisfying quality of the recorded position data. Within this paper, we reconstruct the landing trajectory by a so called Rauch-Tung- Striebel Smoother, which is based on the Extended Kalman Filter. Information about the Instrument Landing System deviation is incorporated into the smoother so that the quality of the aircraft position data could be improved tremendously. Subsequent to the application of the smoother, the aircraft trajectory during landing is shifted based on the specific taxiway location. The assumption that pilots taxi on or very close to taxiway centerlines is well justified in real life operation. Therefore, shifting the aircraft trajectory such that the deviation from the specific taxiway centerline is minimized further increases the quality of the reconstructed trajectory.