3-D tracking of air targets using a single 2-D radar

Three-dimensional (3-D) aircraft tracking using two-dimensional (2-D) radar measurements is a common task in air traffic control (ATC) systems. In this paper, a new algorithm using a 2-D ATC radar, called HPEKF with probabilistic data association (HP-PDA-EKF), is proposed for aircraft tracking with false alarms and missed detections. An improved filter initialization technique is also proposed to yield better estimates. To mitigate the degradation in altitude estimation accuracy with increasing aircraft distance, ATC waypoints are used as extra measurement information, and a new height-parametrized cascaded PDA filter (HP-CPDAF) algorithm is proposed to make use of waypoints. The posterior Cramér–Rao lower bounds (PCRLBs) quantifying the achievable accuracies of these two filters are derived. Simulations are carried out to analyze the relationship between aircraft distance, waypoint accuracy and state estimation accuracy. The viability of using a single 2-D radar for 3-D ATC and the usefulness of the proposed algorithms under different operating conditions are analyzed. Simulation results demonstrate the validity of the proposed algorithms.