Joseph Vignola
Naval Res. Lab., Code 5136, 4555 Overlook Ave., Washington, DC 20375-5000
Brian H. Houston
Naval Res. Lab., Washington, DC 20375-5000
A noncontact tool for measuring simultaneously the three components of vibration-induced displacement on the surface of underwater structures has been designed and constructed. From a distance of approximately 2 ft from the surface of a target structure the three components of motion can be measured. Data for acoustic studies can be obtained by collecting data at a series of points on the surface. Optical fiber is used so that a compact optical probe with no electronics is the only device in the water. The majority of the hardware, both optical and electrical, are located on an optical bench that does not need to be near the probe or target structure. An analysis of the sensitivity, frequency response, and other performance characteristics of the system will be included.