Penn State's Applied Research Laboratory contributions to underwater acoustics

The Applied Research Laboratory (ARL) at the Pennsylvania State University has had a rich history of research and development in the field of underwater acoustics dating from its founding in 1945. The author reviews some of the important contributions made over the intervening decades in sub-fields such as sound propagation, scattering, transducers and arrays, signal processing, autonomous systems decision making, structural vibration and sound radiation, and hydro acoustics. The Laboratory was established by the US Navy as a derivative of the Harvard Underwater Sound Laboratory following World War II. Dr. Eric Walker, the first Director, was charged with continuing research and development on acoustically guided torpedoes following his highly successful effort during the war. In 1949, the Garfield Thomas Water Tunnel was constructed to further the understanding of flow-driven underwater acoustic phenomena, such as cavitation and flow induced vibration as examples of early achievements. Due to a growing need for scientists and engineers educated in acoustics, the Navy encouraged Penn State to establish its Graduate Degree Program for Acoustics in 1965. While the Program covers a broad scope of acoustic disciplines, it has a served a significant role in the development of the underwater acoustics field.