A HORIZONTAL MISS DISTANCE FILTER SYSTEM FOR SUPPRESSING FALSE RESOLUTION ALERTS

摘要

A horizontal miss distance filter system (220) is provided for inhibiting resolution alert messages from an air traffic alert and collision avoidance system (210) to a pilot's display (230). The horizontal miss distance filter employs a parabolic range tracker (10) to derive a range acceleration estimate (11) utilized to discriminate intruder aircraft (110) having non-zero horizontal miss distances. The horizontal miss distance calculated from the range data provided by the parabolic range tracker is compared with a bearing based horizontal miss distance provided by a bearing based tracker (22). The smaller of the two calculated horizontal miss distances defines a projected horizontal miss distance which is compared with a threshold value. Any resolution alert for intruder aircraft whose projected horizontal miss distance is greater than the threshold will be inhibited unless it is determined that the encounter involves a maneuver of one of the aircraft.