Underwater multi-frequency transmitter for seabed characterization

In the underwater acoustic domain, there is a large interest for techniques able to achieve seafloor characterization. The idea is to realize a new kind of source capable of generating simultaneously several frequencies taking advantage of the saturation effect: generated harmonic components of a shock wave become the exploited acoustic beams. The source is unique in time and space so that the multi-frequency responses are inherently perfectly matched. Such a system could offer frequency diversities useful for applications such as detection of sunken oil slicks or sediment characterization. The goal is the study of feasibility of such a source. Three antennas have been tested and experimental results are presented.