Source characteristics and variability of impulsive sources used in ocean acoustics experiments

Two types of impulsive sources were used extensively in the Seabed Characterization Experiment 2017 (SCE2017): Mk-64 Sound Underwater Source (SUS), and the Combustive Sound Source (CSS). Both of these sources rely on the release of chemical energy and hence the radiated acoustic signal is subject to variability from shot to shot. In addition, SUS activates via a pressure sensor and there is variability in the depth of activation, which translates into additional variability in the radiated acoustic signal. A pair of ship-deployed hydrophones was used during SCE2017 to record source waveforms, and in this presentation, various acoustic characteristics of these sources, such as source level, frequency content, and the nature of the time domain signals will be described in terms of their statistical variability. [Work supported by ONR.]