Multitarget Tracking Using Over-the-Horizon Radar

Most conventional multitarget tracking systems assume that in each scan there is at most one measurement for each target. This assumption is, however, not valid for over-the-horizon radar (OTHR), where a target can generate multiple measurements through different propagation modes. A typical multitarget tracking algorithm may fail in this system. For tracking multiple targets using OTHRs, we propose an approach named the decentralized multipath multiple-hypothesis tracker (DM-MHT), where uncertainties in both measurement origin and measurement mode are handled jointly. In DM-MHT, when forming the global hypotheses, each mode first forms local hypotheses separately, because the measurements generated by the same target through different propagation modes are rather different. This largely simplifies data association, and the best global hypotheses are obtained by solving a constrained integer programming problem. Then the measurements that are associated with the same track through the different propagation modes can be used to obtain the overall estimates. The overall estimates are fed back to the corresponding propagation modes to improve tracking performance. Simulation results demonstrate that the proposed approach is effective, and its computational complexity is greatly reduced compared with the existing multiple-detection MHT.