W. A. Kuperman
Marine Phys. Lab., Scripps Inst. of Oceanogr., Univ. of California, San Diego, La Jolla, CA 92093-0238
Underwater acoustics is in a period of renaissance with researchers actively pursing studies in many areas from short-range high-frequency shallow water acoustics to global low-frequency acoustics. There has been renewed interest in inhomogeneous sediment acoustics as well as propagation in very shallow water bounded by these sediments. The recent Office of Naval Research ``SRP'' program studying deep water boundary reverberation has not only been fruitful, but has also laid the foundation for innovative research in the area of boundary scattering in coastal water acoustics. On the other scale, the Heard Island Feasibility Test as described by 18 papers in the October 1994 issue of JASA has re-awakened interest in the myriad of possibilities of monitoring all scales of the ocean using acoustic methods. In an expanding number of efforts, underwater acoustics is distinguishing itself as developing the most physically based signal processing schemes presently being considered in any field. These and other hot topics will be discussed.