Abstract:
The bubble size distribution and bubble motion information are critical to understanding underwater sound propagation and acoustic roles of bubbles in the ocean. Some of the conventional linear and nonlinear acoustic bubble sizing techniques are reviewed. For a bubble rising velocity measurement a nonlinear Doppler technique is discussed. For ocean applications, a new semicoherent acoustic bubble sizing technique based on the sound-speed information as well as sound attenuation from the extinction cross section of bubbles instead of direct sound-speed measurement is proposed.