“…ET-PHD-based algorithms [1,2,3,4,5] are capable of estimating the target extent and measurement rates as well as the kinematic state of the target. For the weak extended target, track-before-detect (TBD) methodology, which makes full use of multi-scan, has been employed to develop Hough transformation-based TBD [6], dynamic programming-based TBD [7], Grey Wolf optimization-based (GWO) TBD [8], and particle filter-based methods [9]. The existing methods [1,2,3,4,5,6,7,8,9] have achieved excellent tracking performance.…”