R. K. Jeffers
S. G. Boucher
Airmar Technol. Corp., Meadowbrook Dr., Milford, NH 03055
Both dual-beam and split-beam array transducers are widely employed in underwater sonar systems. The split-beam principle is used to find the position of individual targets, for target strength measurements and fish stock assessment. The dual-beam array transducer can transmit signals on one beam and receive the echoes with either one or two beams and has been widely used for target strength measurements and fish stock assessment. Here, a new array transducer has been developed, which combines the strengths of split-beam and dual-beam array transducers. The dual-beam mode is achieved by driving the linear array elements with Chebyshev weighting, while the split-beam mode is obtained by driving the quadripartite subarrays. Furthermore, this new array transducer can transmit signals in split-beam mode and receive the echoes in the dual beam mode, or vice versa. The configuration of the new array transducer will be presented. The beam patterns at different transmitting and receiving situations have been numerically simulated.