Sliding Backward Recursive EKF Bearings-Only Target Tracking Method

In the field of target location and tracking, when only one observer is present and only the bearings of the target can be obtained, passive bearings-only underwater target tracking by a single observer is difficult. In engineering applications, the time of observation is short and the amount of data is sometimes small, which makes target location and tracking more difficult. In this study, the principle of a conventional extended Kalman filter(EKF) is studied and the characteristics of state estimation changes in bearings-only target tracking by a single observer are analyzed and proved by formula derivation. Considering the special background of short-term observation and the existence of a small amount of data, this study proposes a sliding backward recursive EKF method. Through a combination of backward and forward recursion, the data are reused and estimation errors are reduced. In a simulation of different observation noises and noise covariance estimates, results show that the proposed method generates lower errors than the conventional EKF for bearings-only target tracking by a single observer using a small amount of short-term observation data.