Detection and Tracking of Underwater Targets Using Directional Sensors

The PLM-MDAEM algorithm is proposed for multitarget detection and tracking in cluttered three dimensional (3-D) underwater environments. The measurements are time delays of arrival (TDOA) of passive transient signals. The (underwater) observer platform is modelled as consisting of a number of 3-D ideal geometric bodies. The receiving sensors used to derive the measurements are directional and are fixed onto the observer. By the PLM-MDAEM the measured data is assumed to contain only one target, and the measurements related to all other targets (the presence and/or number of which is not known) are modelled as clutter. The algorithm extracts targets from the measurements batch in a sequential manner as it maximises a set of partially modelled likelihood functions. A detection algorithm is applied to verify whether each motion parameter vector estimated in this way corresponds to a true target in the TDOA measurements batch. Simulation results are presented for a two-target tracking scenario.