Abstract: An array of piezoelectric transducers from which acoustical energy is emid at a low and high frequency within a predetermined frequency band, synthesizes a localized underwater simulation of a remotely located explosion pressure field, by programmed computer control over the electrical energy input from a signal frequency generator transmitted through power transfer circuitry to the array of acoustic projecting transducers.

Abstract: An inexpensive decoy which simulates the evasive tactics of a submarine ur attack for pulse echo type search systems and which can be ejected through the flare tube of a submarine.

Abstract: An apparatus for extracting, storing and repetitively replaying a broadband atasample is fabricated from proven electronic components to assure long term reliability and reproducibility. A broadband acoustic signal is digitized and stored in a RAM until it is loaded with the desired signal. An adjustable clock controls the rate at which the stored signal is loaded and repetitively displayed so that its spectrum and characteristics can be fully analyzed. Appropriate filters are provided on the input and output sides to block incoming signals outside of the range of interest and those signal components attributed to the variable clock. Selection of particular portions of the stored desired signal may be addressed for detailed analysis on a repetitive basis if needed.