Design and application of high power parametric sonars

A design procedure is presented for an underwater acoustic source that utilizes the medium\´s nonlinearity to generate energy at the difference frequency of the high level, or primary, frequencies. Several designs are presented and the results compared with experimental data. One of these experimental systems develops source levels as high as 220 dB// Pam at a difference frequency of 14 kHz. The peak envelope power input to the projector is 20 kW for this system. Several attractive applications are described and verified by field measurements. These applications include echo ranging and bottom, subbottom, and deep scattering layer profiling.