Abstract: A sonar system for transmitting and/or receiving sonar beams with a desired beam pattern or patterns. The system has a transducer having a linear array of transducer elements, which is driven by element driving signals to project a sonar beam and which generates element receive signals in response to a received sonar signal or sonic wave. A control unit controls the transducer and is configured to generate the element driving signals from a waveform signal based on a set of drive pattern weightings associated with a desired beam pattern to project from the transducer. The control unit is also configured to apply a set of receive pattern weightings to the element receive signals, the receive pattern weightings associated with a desired beam pattern to be detected or sensed received by the sonar system. The drive pattern weightings and receive pattern weightings comprise an amplitude component and polarity component.

Abstract: A sonar system for transmitting and/or receiving sonar beams with a desired beam pattern or patterns. The system has a transducer having a linear array of transducer elements, which is driven by element driving signals to project a sonar beam and which generates element receive signals in response to a received sonar signal or sonic wave. A control unit controls the transducer and is configured to generate the element driving signals from a waveform signal based on a set of drive pattern weightings associated with a desired beam pattern to project from the transducer. The control unit is also configured to apply a set of receive pattern weightings to the element receive signals, the receive pattern weightings associated with a desired beam pattern to be detected or sensed received by the sonar system. The drive pattern weightings and receive pattern weightings comprise an amplitude component and polarity component.

Abstract: A swath beam acoustic transducer (100) for projecting and/or receiving acoustic swath beams (108). The transducer comprises an array of active acoustic elements (104) that are arranged to collectively provide an elongate concave radiation surface (106) with an associated acoustic aperture (110). The array of active acoustic elements (104) is operable to project and/or receive acoustic swath beams (108) via the radiation surface (106).

Abstract: A beam forming system includes one or more beam forming elements that are arranged to provide a non-planar doubly ruled radiation surface. The surface is defined by two families of rulings such that the length of the rulings within each family are configured to provide a radiation surface with substantially straight boundary edges, and the beam forming system is arranged to form acoustic beams.

Abstract: A swath beam acoustic transducer (100) for projecting and/or receiving acoustic swath beams (108). The transducer comprises an array of active acoustic elements (104) that are arranged to collectively provide an elongate concave radiation surface (106) with an associated acoustic aperture (110). The array of active acoustic elements (104) is operable to project and/or receive acoustic swath beams (108) via the radiation surface (106).

Abstract: A beam forming system (10) for acoustic or electromagnetic beams comprising one or more beam forming elements (2) that are arranged to provide a doubly ruled radiation surface.

Abstract: A method and apparatus for determining a characteristic, such as the stiffness, of a portion of a wood specimen characterised by the steps of a) producing an acoustic signal in the wood specimen part way along the length of the wood specimen, and b) sensing a response in the wood specimen part way along the length of the wood specimen including a reverberation from a first end of the wood specimen, and c) calculating a characteristic of a portion of the wood specimen from analysis of the sensed response. A related method and apparatus may be used to determine a characteristic of a portion of a tree stem during harvesting of a tree and the characteristic used to optimise the value of a log cut from the stem.

Abstract: A method and apparatus for determining a characteristic, such as the stiffness, of a portion of a wood specimen characterised by the steps of a) producing an acoustic signal in the wood specimen part way along the length of the wood specimen, and b) sensing a response in the wood specimen part way along the length of the wood specimen including a reverberation from a first end of the wood specimen, and c) calculating a characteristic of a portion of the wood specimen from analysis of the sensed response. A related method and apparatus may be used to determine a characteristic of a portion of a tree stem during harvesting of a tree and the characteristic used to optimise the value of a log cut from the stem.