Multiple Detection-Aided Low-Observable Track Initialization Using ML-PDA

In low signal-to-noise ratio or heavy clutter environments, target track initialization is a challenging task. The maximum likelihood probabilistic data association (ML-PDA) algorithm has been demonstrated to be effective in dealing with this issue. In practical scenarios, multiple signals from one target via different propagation paths can be detected in a scan. Signals from different propagation paths convey useful information and can improve track initialization performance. However, the conventional ML-PDA algorithm assumes that a target can generate at most one detection per scan. That is, it cannot handle multiple target-originated measurements per scan correctly, nor take full advantage of the additional information contained in those seemingly extraneous returns. In this paper, a multiple-detection ML-PDA (MD-ML-PDA) estimator is proposed to rectify this shortcoming. The proposed estimator exploits the additional information available in all measurements by considering the combinatorial events of association that are formed from MD patterns. It is capable of handling the possibility of multiple target-originated measurements per scan with less-than-unity detection probability for various paths in the presence of clutter. The proposed MD-ML-PDA estimator is applied to a simulated sonar target tracking scenario. The same algorithm can be used on other angle-only tracking problems as well. Results show that MD-ML-PDA can effectively handle multiple target-originated measurements and yield improved track initialization performance over the traditional single detection ML-PDA. The Cramer–Rao lower bound for MD track initialization is also derived.