Textbook in PDF format This book highlights the principles and technology to solve the challenges of multi-target tracking in underwater target detection, with sonar equipment research as the background. While underwater acoustic target detection primarily determines the presence or absence of targets, it fails to provide the information about batches. Multi-target tracking, on the other hand, focuses on addressing issues including dividing target batches, obtaining target start and end times, obtaining information about target quantity, as well as filtering out false targets and smoothing trajectories. For sonar equipment, especially that on unmanned platforms, multi-target tracking is of utmost significance