Advances of research work in underwater acoustics

Accostics is an ancient and young science, underwater acowtics is a branch of acoustics. The advances of researeh in recent years are discussed in this paper. Which include new type of transducer materials, non-linear underwater acoustics, matched filter processing, robust signal processing, underwater communication, synthetic aperture imaging technique, data fusion, acoustic tomography, underwater GPS technique etc. Some new concept and idea, such as military oceanography model-based sonar design, are also reviewed in this paper.