Underwater acoustics at the Naval Air Development Center

Abstract

Much of the progress in underwater-acoustic research from World War II to the present has been funded by government agencies for development of sonar systems. Although sonar is often considered the domain of surface ships and submarines, the naval aviation community has made significant contributions to basic underwater-acoustic measurement and to acoustic-system development. In the 1940s, the U.S. Navy established the Naval Air Development Center (NADC) in Warminster, Pennsylvania, as the lead laboratory for naval aviation research and development and a substantial part of the work of that laboratory supported development of air-deployed sonar systems. Partnerships between NADC, other laboratories both domestic and foreign, and manufacturers produced a stream of innovative, inexpensive, and expendable devices to support the missions of marine patrol aircraft; these same devices were used extensively for ocean-acoustic measurements. Basic bottom-reflection loss, ambient-noise level and directivity, and reverberation measurements were made using air-deployed sonobuoys and acoustic sources. While lacking the precision of ship-based measurements, the cost of airborne surveys was low, deployment was rapid, and the coverage was ultimately global.