SUMMARYTarget tracking filters with a low computational load are desired in air traffic control systems in order to simultaneously search and track multiple aircraft. The applications of the α-β filter and the Kalman filter have been widely studied. Although excellent tracking accuracy can be obtained for linear motion by the α-β filter, the tracking accuracy degrades for a maneuvering target, the difference between the predicted position and the actual target position becomes large, and mistracking where the target is lost may occur. While there has been research on filters that estimate the acceleration, these filters could only be used when there is little maneuvering and the computational load is huge. In this research, we propose a method that adds an acceleration term during turning motion as the tracking filter for maneuvering motion and not just linear motion and estimates the turning acceleration from past estimated positions of the target. We also reduce the tracking errors for a maneuvering target. We use simple trajectories of the target in computer simulations and compare the proposed method to conventional filters to demonstrate its effectiveness. And we evaluate the performance of the proposed acceleration estimation method.

In this paper, we propose a multiple radar target tracking system that uses a mobile station, which is effective in reducing cross‐range errors. The mobile station is an airplane equipped with radar and tracks the target by radar while in flight. By controlling the motion of the mobile state according to the proposed algorithm, the beams from the radars to the moving target can be orthogonal to or nearly orthogonal to each other compared to a multiple radar target tracking system that uses only conventional stationary stations. Combining the measurements from radars placed so that their beams to the target are orthogonal or nearly orthogonal can lessen the effect of increases in the cross‐range errors and can obtain excellent tracking accuracy. Computer simulations compare the proposed method to a multiple radar target tracking system that used only conventional stationary stations and demonstrate its ability to obtain excellent tracking accuracy for distant targets. © 2002 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 85(8): 1–12, 2002; Published online in Wiley InterScience (http://www.interscience.wiley.com). DOI 10.1002/ecja.1113

SUMMARYA Kalman filter that can estimate equal velocity and equal angular velocity by means of angular velocities in two directions is proposed. In the proposed tracking filter, the angular velocity is calculated in two directions from the difference of the two velocity vectors obtained from the observation values of the past three samples. By making use of the fact that the speed of rotation of the velocity vector coincides with the angular velocity in constant-speed circular motion, the variation of the velocity is expressed without using an acceleration term. Since the calculation of the rotating acceleration is not needed, the error due to shift of the estimated center and the estimated radius in Ref. 10 can be made zero and the tracking accuracy can be improved. The effectiveness of the proposed tracking filter is demonstrated with regard to the tracking accuracy and computational load by computer simulation.

No abstract

SUMMARYIn this paper, we propose a multiple radar target tracking system that uses a mobile station, which is effective in reducing cross-range errors. The mobile station is an airplane equipped with radar and tracks the target by radar while in flight. By controlling the motion of the mobile state according to the proposed algorithm, the beams from the radars to the moving target can be orthogonal to or nearly orthogonal to each other compared to a multiple radar target tracking system that uses only conventional stationary stations. Combining the measurements from radars placed so that their beams to the target are orthogonal or nearly orthogonal can lessen the effect of increases in the crossrange errors and can obtain excellent tracking accuracy. Computer simulations compare the proposed method to a multiple radar target tracking system that used only conventional stationary stations and demonstrate its ability to obtain excellent tracking accuracy for distant targets.