Abstract: Some aspects of the present system include one or more tubs and one or more lids configurable in various arrangements. In some configurations, the tub includes a base, a sidewall extending from the base in a first direction and defining an opening, and a ridge extending from the base in a second direction and defining one or more protrusions. In some configurations, the lid includes a sidewall and a floor cooperating to at least partially define a recess and a plurality of tabs extending from the floor, where each tab is displaceable from a first position to a second position. In some aspects, when the lid is coupled to the tub in a first arrangement, at least one of the one or more protrusions of the ridge engage with a respective one of the plurality of tabs of the lid to couple the lid to the base.

Abstract: Processing of electrical signals representative of incident and reflected acoustic signals generated by underwater explosion and comprising primary and secondary impulse, or bubble pulse, peaks. Acousto-optic diffraction and optical Fourier transform of the primary or explosive incident signal is performed and photographically recorded to provide a bubble pulse spatial filter. The filter is used in performing subsequent acousto-optic diffraction and optical Fourier transforms to derive impulse response, bottom loss, and an output electrical signal representative of the reflected signal, without the bubble pulse.