Ground target tracking of a temporarily invisible target due to topographic constraints

It is possible that topographic constraints hide targets in ground target tracking. It is important that hidden targets are tracked effectively when they are invisible during hidden portions of their motion. In addition to that, existence of heavy clutter makes the problem even more challenging. To address this problem, an airborne GMTI radar with a VSIMM-PDAF tracker is considered. Traditional approaches make assumptions regarding the motion of the target during hidden modes, e.g., constant velocity assumption. However, in reality such assumptions do not model the true target behavior and the track is dropped if the assumption is not satisfied. To mitigate the target drop problem a new approach is presented in this paper. Firstly, a stop model is integrated into the VSIMM-PDAF algorithm. Using the flexibility of the stop model, then secondly a hide model is developed. The hide model enables the tracker to track the targets independent of the time spent and independent of the target velocity during the hidden mode. The root mean square position error and velocity error performances of the algorithm show that there exists a short recovery period in which there is a rise in error whenever the target becomes visible again and that tracking continues thereafter.