SUMMARY

Tags and transponders are commonly used for underwater applications to mark underwater targets or tracks of interest to facilitate the navigation of underwater vehicles equipped with SONAR. However, most underwater tag identification systems rely on active source system and electronic hardware to broadcast a beacon acoustic signal. This thesis work develops lower-cost, totally passive acoustic tags ("AcoustiCode") that are able to encode information which can be read by a conventional high-frequency side-scan SONAR. The AcoustiCode tags utilize Braggs scattering principle to create a unique reflected beampattern (an acoustic signature) that can be detected by a side-scan SONAR. The information is encoded in the unique spatial beampattern of each AcoustiCode tag. Numerical simulations and experimental testing in an underwater tank are conducted to investigate the performance of the proposed approach.