Abstract: A sonar system has at least two separated bottom-mounted acoustic modules, each module including a projector for generating horizontal sound beam, a vertical line receive array for monostatic and bistatic detection, and a high frequency, upward-directed transducer for providing a steerable vertical beam to ensure full water column coverage by the use of surface reflections to minimize shadowing caused by high relief bottom topography.

Abstract: A sonar system for use in a water body includes a projector on the bottom of a water body for generating and transmitting a direct beam of acoustic energy. A receiving array is immersed in the water body outside the direct beam for detecting reflections from an target in the direct beam. The receiving array may be a horizontal or vertical linear array of hydrophones in the water body. The array of hydrophones may have output signals coupled to an A/D convertor and a multiplexor for digitizing and multiplexing the signals to prepare for transmission and analysis of the signals. A pair of separated projectors on the bottom of the water body may generate parametric acoustic arrays for transmitting direct beams of acoustic energy through the water body towards each other. A receiving array immersed in the water body outside the direct beams detect any reflections from an object in the acoustic beams.