Patent ID: 9218799
Filing Date: 2015-12-22
Classification: B06B,G01S,G10K

Abstract:
1. An underwater swath beam acoustic transducer for projecting and receiving far-field acoustic swath beams through water, comprising: an elongate support structure defining a longitudinal axis of the transducer; an array of active acoustic elements, supported by the elongate support structure, that are arranged to collectively provide an elongate concave radiation surface with an associated acoustic aperture that extends in the direction of the longitudinal axis of the transducer such that the radiation surface has a concave cross-sectional profile along the longitudinal axis of the transducer, and each active acoustic element being operable to project an individual acoustic beam from the radiation surface toward a near-field focal zone of the transducer; and a control system that is electrically connected to the active acoustic elements and which is configured to generate electrical driving signals to drive each of the active acoustic elements so as to project far-field acoustic swath beams through water beyond the acoustic aperture of the transducer, the far-field acoustic swath beams each being a superposition of all of the individual acoustic beams such that in the far-field, beyond the focal zone and acoustic aperture of the transducer, the acoustic swath beams have a wide field of view in a plane that is transverse to the longitudinal axis of the transducer, a narrow width in the direction of the longitudinal axis of the transducer, and an acoustic intensity that is substantially uniform across the field of view, and wherein the control system is further configured to receive and process electrical signals from the active acoustic elements that are generated in response to swath beams incident upon the radiation surface that are reflected back to the transducer from the far-field beyond the focal zone and acoustic aperture of the transducer.