Figure 2.

Example results for tracking target with different maneuverability. The moving trajectories are in the left column and the tracking errors of the target position, extent, and orientation are shown in the right column. True target (black contour) is compared with the proposed two methods, i.e., GPR-UKF (magenta contour) and GPR-AUKF (red contour), and other competing method, GPR-EKF (green contour). The black dashed line represents the moving trajectory which is connected by the center position of the target at each moment, and the measurements are depicted as black dots. (a) Motion model: S1, (c) Motion model: S2, (e) Motion model: S3, (b) Tracking error of S1, (d) Tracking error of S2, (f) Tracking error of S3.