I. Introduction
Underwater acoustic target recognition (UATR) has long been a crucial and hot topic in a variety of fields, such as ocean exploration and national security. In ocean exploration, UATR can be utilized to make discoveries, detect and analyze seabed topography, and search for resources that are vital to the economy [1], [2]. In national security, UATR plays an essential role in undersea surveillance, military target detection, vicinagearth security [3], and underwater warfare systems [4]. Furthermore, UATR has also been extensively applied in underwater communication, marine biology research, and underwater equipment maintenance [5]. However, the applications of UATR in both military and commerce are significantly impeded by the complexity of underwater environments, where, in addition to the noise from multiple sources, multipath reflected sound waves coexist and deteriorate the original signal.