Underwater explosions have been studied intensively in the United States since 1941 [e.g., Cole (1945)]. Research to date primarily focuses on the initial shock and subsequent pressure waves caused by the oscillations of a “gas-globe” that is the result of a charge detonation. These phenomena have relatively short timescales (typically less than 2 [s]). However, as the gas globe rises in the water column and breaks the surface, it leaves behind a residual bubble cloud which has been markedly less studied. A recent experiment measured the spatial and temporal acoustic response of the bubble cloud resulting from a charge detonated at 15.2 [m] (50 [ft.]) depth. A directional projector was used to propagate a 40 kHz continuous-waveform (CW) pulse and a linear FM (5 − 65 kHz) pulse through the bubble cloud to two hydrophone arrays in order to measure the energy lost in propagating through the bubble cloud as well as backscattered to the vicinity of the acoustic projector. This thesis focuses on estimating and modeling the bubble population resulting from an underwater explosion (UNDEX). The resulting model is used to predict attenuation through, and backscatter from an UNDEX bubble cloud, and is compared to measured data.
