“…Then it calculates the likelihood function for each track and the tracks with likelihoods less than a predefined threshold are deleted. In the nearest neighbor Kalman filter (NNKF) approach (Singer 1971, Sea 1971, Singer 1973, the contact that has the smallest statistical distance to the predicted target track is considered as a true target observation and the others are considered as clutter. The probabilistic data association filter (PDAF) introduced in (Bar-Shalom 1975), provides a suboptimal Bayesian approach for data association in the single target tracking problem.…”