Altitude estimation for 3-D tracking with two 2-D radars

This paper first proposes a method to estimate the altitude of an aircraft using two 2-D radars for Air Traffic Control (ATC) applications. Assuming that the aircraft flies with a nearly constant velocity and nearly constant height, we first estimate its velocity, initial position in 3-D coordinates from the measurements of two 2-D radars using a maximum likelihood estimator. Next, we incorporate the estimates as initial values for 3-D flight tracking that uses an extended Kalman filter (EKF). Furthermore, a multiple model approach is adopted to further improve the tracking performance. The simulation results are shown to demonstrate the effectiveness of the proposed method.