Six decades of evolution in underwater acoustics at the Applied Physics Laboratory - University of Washington (APL-UW)

Professor Joe Henderson of the University of Washington physics department formed the Applied Physics Laboratory during WWII. The initial efforts by the Laboratory were to redesign the magnetic influence exploders used in US torpedoes. The first of a long line of APL-UW success stories in underwater acoustics (UA) was development of transducers used in the Bikini Atoll Able test (1946). Those transducers, used to trigger other instrumentation, proved critical. Combining UA and torpedo expertise brought APL-UW to the forefront of tracking range design, construction and deployment in Dabob Bay, Nanoose and St. Croix in the 50's and 60's. Understanding the torpedo behavior seen in tracking ranges required measuring both the ocean environment and the acoustics within that environment. Making those measurements, as well as development and testing of models based on those measurements, also became standard operating procedure at APL, led in the 50's by Drs. Stan Murphy and David Potter. This blueprint of applied research motivating basic research, and the pursuit of basic research via ocean experiments and high fidelity modeling, continues to this day. The presentation will follow this evolution using a small subset of both the ocean experiments carried out and APL-UW research papers published as examples.